Rheumatology Pearls

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TRAPS patients (TNF receptor-assoc. periodic syndrome) have a mutation in the TNFRSF1A (TNF receptor) gene.
In any patient w/ patellofemoral disease, rule out hypermobility & pes planus. If present, shoe orthotics are a necessary part of therapy.
Muscle cramps, pain, or myoglobinuria brought on by exercise suggests a metabolic myopathy
IV drug users are susceptible to septic arthritis with unusual organisms (gram negatives) and in atypical axial sites (sternoclavicular).
Gouty arthritis is associated with nodal OA, particularly in elderly women with renal failure, HTN, or CHF on long term diuretic therapy.
If a patient with PMR consistently requires > 20 mg of prednisone a day to control the disease symptoms, the diagnosis is probably wrong.
In acute gonococcal septic arthritis, GC is rarely seen on gram stain or by culture. Furthermore, low WBC counts on synovial fluid do occur.
Limited joint mobility in a patient with diabetes mellitus indicates increased risk for microvascular disease, especially retinopathy.
Life expectancy is shorter in patients with RA, & survival rates are comparable to Hodgkin's, diabetes, & 3-vessel coronary artery disease.
P-155 antibodies are directed against transcriptional intermediary factor & are most closely linked to malignancy associated dermatomyositis
The most common arthritic manifestation of relapsing polychondritis is migratory tenosynovitis.
GCA accounts for 16% of cases of fever of unknown origin (FUO) in patients over 65 years old (but <2% of all cases of FUO).
Eye involvement is common in spondyloarthropathies and usually involves the middle layer of the eye-uveal tract
De Quervain's tenosynovitis refers to tenosynovitis of the abductor pollicis longus and extensor pollicis brevis tendons.
The arthritis of acute rheumatic fever is usually migratory and affects predominantly the large joints.
In relapsing polychondritis, an immune response against collagens II, IX, and XI has been demonstrated for many patients.
HIDS patients (HyperImmuno-globulinemia D with periodic fever Syndrome) have a mutation in the MVK (mevalonate kinase) gene.
A patient needs a calcium (corrected for albumin lvl) X phosphorous product of at least 24 to properly mineralize bone
Hip fractures are assoc w/ permanent disability in nearly 50% of patients and w/ 20% excess mortality rate compared to age-match controls
The most common metabolic myopathies associated with myoglobinuria are CPT II deficiency and McArdles disease
In obese patients with knee OA, losing even just one pound results in a 4-pound reduction in knee-joint load for each step.
In GCA, diagnostic histopathologic findings on temporal artery biopsy can be seen even 2 weeks after the institution of steroid therapy.
TRAPS patients (TNF receptor-assoc. periodic syndrome) experience attacks of fever, migratory rash, and periorbital edema, lasting 1-3 weeks
The ENA 4 is comprised of four tests: anti-Sm, anti-RNP, anti-La, & anti-Ro. Often used in the evaluation of connective tissue diseases.
Clubbed fingers & tender periostitis of lower extremities can be clinical signs of a lung tumor. Hypertrophic Osteoarthrophathy
Nephrogenic systemic fibrosis (NSF) is seen exclusively in patients with renal insufficiency who have undergone a gadolinium (contrast) MRI
B Lymphocyte Stimulator (BLyS) binds to 3 different receptors with variable affinity. BAFF-R more than BCMA more than TACI.
Procainamide is associated with the highest incidence of drug-induced lupus of any available drug. Incidence with prolonged therapy is ~30%.
In Duchenne muscular dystrophy, there is a characteristic hypertrophy of the calves but no muscle tenderness.
Erosive osteoarthritis (EOA) is an aggressive subset of OA. The classic radiographic findings include â€œgull-wingâ€ & â€œsaw-toothâ€ deformities.
Several clinical trials have demonstrated the benefit of quadriceps strengthening on pain and function in patients with OA of the knee.
Delayed-onset neutropenia is an increasingly recognized potential complication following rituximab infusion
Mixed cryoglobulinemia is a systemic vasculitis associated with hepatitis C. It is associated with purpura, arthralgia, and asthenia.
Complex regional pain syndrome (CRPS) Type I, (formerly reflex sympathetic dystrophy (RSD)), does not have demonstrable nerve lesions.
Interleukin 6 (IL-6) is a pro-inflammatory cytokine and one of the most important mediators of fever and of the acute phase response.
Vascular Ehlers Danlos (EDS type IV) patients demonstrate abnormalities in type III procollagen (found in hollow organs and vessels).
Belimumab is the first biologic therapy approved for the treatment of lupus. It is a monoclonal antibody which targets the cytokine BLyS.
In lupus patients, IRF5, IRAK1, and STAT4 genes are important for dendritic cell type I interferon production.
Rheumatoid factor (RF) describes an antibody (IgM, IgG, or IgA) which targets the Fc portion of IgG. Together, they form immune complexes.
Osteoarthritis affects nearly 27 million people in the US, accounting for 25% of visits to PCPs, and half of all NSAID prescriptions.
In psoriatic arthritis, nearly 15% of patients will develop psoriasis AFTER the onset of arthritis.
Septic joint infections are divided into gonococcal and non-gonococcal. Common causes of non-gonococcal are staph, strep, and E. coli.
Polymyalgia rheumatica (PMR) is almost exclusively a disease of adults over the age of 50. Prevalence increases progressively with age.
C-reactive protein is normal in ~ 70% of patients w/ rheumatoid arthritis early in the disease course and even if elevated is non-specific.
Rule out vitamin D insufficiency/ deficiency in patients losing bone mineral density while receiving therapy for osteoporosis.
In a patient with diffuse scleroderma, anti-RNA polymerase III is the antibody most associated with an increased risk for renal crisis
Livedo reticularis is strongly associated with the occurrence of arterial ischemic events in the antiphospholipid antibody syndrome.
PML should be considered in lupus patients with progressive neurologic deficits especially if immunosuppression is ineffective.
Forearm ischemic test: If lactate does not rise but ammonia does - defect in glycolysis (such as McArdles)
Kienbock's disease is also known as avascular necrosis of the lunate bone (wrist), or lunatomalacia.
Legg-Calve-Perthes disease is avascular necrosis of the hip due to insufficient blood supply. Most commonly affects young, overweight boys.
The length of a cane should produce 20â€“30Â° of elbow flexion when the cane is planted approximately 6 inches lateral to the 5th toe.
The risk of lupus panniculitis is associated with discoid lupus, leg ulcers, serositis, and myositis, but not proteinuria. #ACR2012
The malar rash of SLE is not transient. Because inflammation takes time to resolve, lupus rashes do not resolve within hours.
Multicentric reticulohistiocytosis is characterized by severe destructive arthritis and cutaneous papulonodular lesions.
Patients with polymyositis and anti-SRP antibodies have more cardiac involvement, a poor prognosis, and a poor response to therapy.
Patients who undergo knee arthroplasty are at an increased risk of clinically important weight gain following surgery. http://bit.ly/106lCIE
The arthropathy associated with hyperparathyroidism is characterized by subperiosteal bone resorption of the middle phalanges.
Eosinophilia-myalgia syndrome is characterized by pruritus, cutaneous lesions, sclerodermoid changes, arthralgias, myalgias and eosinophilia
Muscle sxs w/ short bursts of high-intensity exercise and the 2nd wind phenomenon are characteristic of a glycogen storage disease
Type 1 autoimmune pancreatitis (AIM) is an organ manifestation of IgG4-related disease. Type 2 AIM appears to be a disease of its own.
Wilson’s dz- Dx by LOW serum ceruloplasmin, HIGH urinary copper, hepatic copper levels, or mutations in ATP7B gene
One of the most common sites for erosions in patients with rheumatoid arthritis is the lateral aspect of the head of the 5th MTP.
Acute calcineurin inhibitor nephrotoxicity causes vasoconstriction of the afferent and efferent glomerular arterioles and a reduction in GFR
Anti-MDA5 autoantibodies are associated with amyopathic dermatomyositis. Patients are at increased risk for rapidly progressive ILD.
Skin ulcerations plus anti-155/140 antibodies in the setting of dermatomyositis suggest an associated underlying malignancy
Excessive overgrowth of craniofacial bones in craniometaphyseal dysplasia may result from a loss of function in ANKH gene product.
The incidence of chondrocalcinosis increases with age, and over 30% of persons over 75 have chondrocalcinosis on the knees.
NOMID (neonatal onset multisystem inflammatory disease) can result from a mutation in the CIAS1 gene, which helps control inflammation.
Foreign bodies such as thorns can lead to chronic tenosynovitis, bursitis & aseptic monoarticular synovitis in relation to the puncture site
The active cyclophosphamide metabolite, phosphoramide mustard, forms DNA crosslinks at guanine positions and leads to cell death.
Radiology findings in Wilsonâ€™s disease can reveal premature osteoarthritis, chondrocalcinosis, and chondromalacia patella. Knees most common
Cellcept (MMF) inhibits inosine monophosphate dehydrogenase, which is a critical enzyme for the for the de-novo synthesis of guanosine.
When considering intra-articular injections for polyarthritis in a JIA patient, triamcinolone hexacetonide is the preferred corticosteroid.
About 10% of patients with giant cell arteritis GCA have upper respiratory symptoms including a sore throat and nonproductive cough.
Rheumatoid arthritis patients with anemia and a ferritin greater than 100ng/ml do not have iron deficiency anemia.
Up to 80% of Stiff Person Syndrome (SPS) patients have an autoantibody against glutamic acid decarboxylase (GAD).
Despite modern therapies, a lupus patient diagnosed at the age of 20 has a 1 in 6 chance of dying by the age of 35.
When palmar fasciitis presents in a woman, think ovarian carcinoma
Children with SLE often require higher doses prednisone than their adult counterparts because of rapid drug metabolism (2 mg/kg vs 1 mg/kg).
Musculoskeletal side effects are seen in 40 to 60% of patients taking aromatase inhibitors like anastrozole
Serum IgA antiendomysial and anti-tissue transglutaminase antibodies are highly specific and sensitive for celiac disease.
A major side effect of IVIg is aseptic meningitis, especially in patients with a history of migraines. Premedication with a triptan may help
When PMR-like symptoms do not respond appropriately to prednisone, other diagnoses should be considered, like PMR associated w/ malignancy.
BLyS is a cytokine expressed on B cells and has been shown to play an important role in B cell proliferation and differentiation.
The most common types of soft tissue rheumatism are subacromial bursitis, epicondylitis, trochanteric bursitis, and fibromyalgia.
Thromboangiitis obliterans (aka Buerger's disease) is strongly associated w/ smoking and the only effective therapy is smoking cessation.
Congenital heart block, due to anti-Ro and anti-La, is most often identified between 18 and 30 weeks gestation.
In patients with scleroderma and abnormal esophageal manometry, almost all will also have abnormal anorectal motility.
Periodontal disease is associated with rheumatoid arthritis but its severity is not correlated with RA disease activity. #ACR2012
Patients with DRESS syndrome often have a prolonged course with frequent relapses despite the discontinuation of the culprit drug
The most predictive factor for a future fall is a previous fall w/in the past 6 months. Almost all hip fractures occur as a result of falls
Movement disorders seen in CNS lupus (tremors, chorea, and extrapyramidal syndromes) may improve with management of the underlying disease.
Crohn's disease articular manifestations tend to be asymmetric, migratory, and pauciarticular with large and small joint involvement.
Diffuse idiopathic skeletal hyperostosis (DISH) is a noninflammatory spondyloarthropathy (aka Forestier's disease & ankylosing hyperostosis)
In most cases of primary angiitis of the CNS, abnormal CSF will be seen, including increased WBCs or an elevated total protein or both.
Systemic AA amyloidosis is the most devastating long-term complication of FMF. Outcomes include nephrotic syndrome & chronic renal failure
PFAPA syndrome (periodic fever, aphthous stomatitis, pharyngitis & adenitis) is seen in children. Fevers occurs periodically every 3â€“5 weeks
The pericarditis of SLE is often painful whereas pericarditis in scleroderma and rheumatoid arthritis is generally painless.
IgG4-related disease is a fibroinflammatory condition characterized by formation IgG4+ plasma cells, fibrosis, a swift response to steroids.
Elevated resting lactate level and/or ragged red fibers on muscle biopsy are characteristic of a mitochondrial myopathy
Myositis patients with positive anti-PL-7 and anti-PL-12 are more likely to have severe ILD and mild or absent myositis
Children with symptoms of a muscle disease without rash almost always have a metabolic or genetic myopathy and not primary polymyositis
HBV infection can present as an arthritis-urticarial syndrome: HCV infection can cause autoantibodies and polyarthritis
All patients with fibromyalgia should be asked about symptoms of sleep apnea. Physical therapy and amitriptyline wonâ€™t work unless corrected
Nontuberculous mycobacterial MSK infections most commonly present as hand tenosynovitis
Pes anserine bursitis is a common finding in patients and/or athletes who present with complaints of anterior knee pain.
Post-steroid injection flares are likely due to crystallization of the steroid within the joint. Pain usually resolves within 1-2 days.
Approximately 10-15% of arthroplasties fail, the most common cause for which is osteolysis (inflammation initiated by arthroplasty debris)
The development of mononeuritis multiplex in the absence of diabetes or compression injuries strongly suggests the presence of vasculitis.
Since probenecid increased urinary calcium excretion in gouty patients, it should be avoided in patients with prior nephrolithiasis.
All patients with newly diagnosed reactive arthritis should have an HIV test. Reactive arthritis develops in 75% of HIV patients w/ HLA-B27.
All patients with rheumatoid arthritis needing pre-op clearance should have c-spine films because of the risk of atlantoaxial subluxation.
Patients who have PM-Scl antibodies typically have an overlap syndrome of polymyositis or dermatomyositis with systemic sclerosis.
The 5 types of psoriatic arthritis are: symmetric, asymmetric, distal interphalangeal predominant, spondylitis, and arthritis mutilans.
Over 50% of patients with long-standing primary hyperparathyroidism will have radiographic evidence of chondrocalcinosis
Anserine bursitis is a major cause of knee pain in some patients with osteoarthritis of the knee.
IL-12 is a strong driver of Th1 cell differentiation. Th1 cells are defined by the production of the cytokine interferon-gamma
A prolonged aPTT suggests the possibility of an lupus anticoagulant (LA), but only about half of all patients with LA have an abnormal aPTT.
Patients with earlier onset SLE are more likely to have renal and neurologic involvement. #ACR2012 #lupus
Lateral epicondylitis is also known as tennis elbow. Medial epicondylitis is also known as golfer's elbow.
Acute calcific periarthritis is a common cause of podagra in young women (hydroxyapatite pseudopodgra). Gout would be much less likely.
Leflunomide is known to cause significant increases in systolic and diastolic blood pressures within 2â€“4 weeks of initiation.
Abatacept is a fusion protein (CTLA-4 Ig) which inhibits the costimulation of T cells by preventing binding of CD28 (T cell) and B7 (APC).
Mycoplasma hominis as an etiologic agent for septic arthritis in patients who have undergone genitourinary manipulation.
Varus alignment (bow-legs) increases the risk of knee OA 5-fold in obese patients. Valgus alignment (knock-kneed) is not as destructive.
â€œRealize that the most important biomarkers (in rheumatology) are the history and physical examinationâ€ â€“ Steve Paget, HSS
GI involvement occurs in ~50% of patients with polyarteritis nodosa (PAN) (with gallbladder and small bowel the most frequently involved).
Th1 cells help defend against intracellular pathogens like mycobacteria. Th17 cells help defend against extracellular bacteria and fungi
The first MTP is the most commonly involved joint in patients with gout. >50% of initial attacks and over time affects >90% of patients.
In Sjogren's, presence of subpleural honeycombing is suggestive of usual interstitial pneumonitis (UIP), which portends the worst prognosis
In Wegener's granulomatosus, a lung biopsy is the most likely site to detect the diagnostic triad of vasculitis, granulomata, and necrosis.
NOMID (neonatal onset multisystem inflammatory disease) symptoms include rash, arthritis, & chronic meningitis leading to neurologic damage.
Never initiate xanthine inhibitor therapy (allopurinol) during an acute gout attack. It can exacerbate and prolong the flare.
Lupus anticoagulant is an immunoglobulin that interacts with platelet membrane phospholipids, increasing adhesion & aggregation of platelets
Most polymyalgia rheumatica (PMR) patients demonstrate striking improvement in their symptoms with 24 to 48 hours of beginning steroids.
Usual interstitial pneumonitis (UIP) is more commonly seen in patients with Sjogren syndrome secondary to RA and SLE rather than primary SS
Iliotibial band syndrome is a common injury in long-distance runners that usually develops with over-training and after vigorous running.
Pulmonary HTN & interstitial lung disease are under recognized complications of systemic JIA that are frequently fatal http://bit.ly/13WQNuA
PMR occurs in about 50% of patients with GCA, while approximately 15 to 30% of patients with PMR eventually develop GCA.
Great apes, dalmatian dogs, & humans are the only mammals that lack a functional uricase gene and, thus, are the only mammals who get gout.
The ARB (angiotensin receptor blocker) losartan has a uric acid-lowering effect.
The axial manifestations of spondyloarthopathies typically do not respond to methotrexate. TNFÎ± antagonists are the treatment of choice.
An IgG1 autoantibody (NMO-IgG) that binds aquaporin 4 (AQP4) has been proposed as the primary autoimmune phenomenon in neuromyelitis optica.
There are currently 171 known types of arthritis, from acromegalic arthropathy to yersinia arthritis.
Posterior tibial nerve compression (tarsal tunnel syndrome) presents with pain & numbness at the sole of the foot, distal foot, toes, & heel
There are approximately 640 muscles in the human body. Muscle constitutes up to 40% of the adult body mass.
Lupus anticoagulant has the most significant odds ratio for the occurrence of CVA, not ACA or anti-prothrombin.
Almost 40% of HLAB27+ ankylosing spondylitis patients will get anterior uveitis. Usually only one eye will be effected at a time.
Hypertrophic lupus erythematosus is a form of discoid lupus characterized by verrucous hyperkeratotic lesions.
Caplan's syndrome describes lung nodules only in patients with both RA and pneumoconiosis related to mining dust (coal, asbestos, silica).
Carpal tunnel syndrome is the most common compression neuropathy. Symptoms include tingling and numbness in digits 1-3 and thenar atrophy.
Those who develop Raynaudâ€™s phenomenon later in life (age >40) are more apt to have secondary Raynaudâ€™s phenomenon.
Calciphylaxis is a rare, painful disorder of metastatic calcification most commonly occurring in patients with ESRD on dialysis
A greater than 4% decline per year in bone mineral density on DEXA suggests treatment failure.
Brucellosis caused by ingestion of unpasteurized dairy products usually presents with sacroiliitis and fever
Leflunomide (rheumatoid arthritis DMARD) works by inhibiting dihydroorotate dehydrogenase (enzyme involved in de novo pyrimidine synthesis).
The major long-term toxicity of hydroxychloroquine use is the development of macular changes and loss of color vision.
In diffuse idiopathic skeletal hyperostosis (DISH), the anatomical location of ossification occurs along the anterior longitudinal ligament
Moyamoya disease is a noninflammatory vasculopathy and notable for stenosis or occlusion of the arteries around the circle of Willis.
The prevalence of carpal tunnel syndrome is increased in the third trimester of pregnancy and it generally goes away after pregnancy.
MCTD combines features of scleroderma, myositis, SLE, and RA and most patients are positive for the anti-U1-RNP autoantibody.
Probenecid is a uricosuric agent used for urate lowering therapy but it is generally not considered effective in tophaceous gout.
When getting a skin biopsy for Henoch SchÃ¶nlein Purpura (HSP), make sure to send a sample for immunofluorescence looking for IgA deposits.
Finkelstein's test is used to diagnose DeQuervain's tenosynovitis. Grasp the thumb and the hand is ulnar deviated sharply to test for pain.
Asians are more prone to Allopurinol hypersensitivity syndrome (aka DRESS) so consider starting at a lower initial dose.
Activated T cells express IL-2R, and engagement of IL-2 results in enhanced T-cell proliferation.
Muckle-Wells syndrome is caused by a defect in the CIAS1 gene. Patients have fevers, sensorineural deafness, recurrent hives, & amyloidosis
Rheumatoid vasculitis overlaps substantially with polyarteritis nodosa and tends to affect the same types of organs.
New unexplained pain located above the neck in a patient over 60 years old should suggest the possibility of giant cell arteritis.
The most serious complication of pauciarticular JIA is uveitis or iridocyclitis (20% of JIA). ANA positive patients are at greatest risk.
The pancreas was the first organ in which IgG4-related disease was identified, but it has now been described in virtually every organ system
Pronator teres syndrome results from median nerve entrapment at the elbow - frequently accompanied by weakness of the index & middle fingers
Independent predictors of disease activity in pts w/ lupus include age, renal activity, immunosuppressant use and pre-existing organ damage
CPPD (pseudogout) can be associated with a wide range of metabolic disorders including acromegaly, thyroid, and parathyroid conditions.
Barefoot walking has been demonstrated to reduce the major force across the knee in patients with medial compartment knee OA.
On a worldwide basis, the most common cause of Erythema nodosum is streptococcal infections (~20% of patients).
Children born to women w/ SLE have increased risk of congenital abnormalities, infections, and cardiac conduction abnormalities. #ACR2012
The vasculitis most commonly associated with hairy cell leukemia is polyarteritis nodosa (PAN).
A prolonged PT in lupus is usually the result of a prothrombin (factor II) deficiency. These patients generally present with hemorrhage.
Wegener's granulomatosus is believed to be two or three times more common than MPA in western countries. This ratio is inverted in Japan.
The most common myopathies confused for polymyositis are acid maltase deficiency and limb-girdle muscular dystrophy
Acetaminophen (Tylenol) potentiates the anticoagulant effect of coumadin so use caution with prescribing both.
Dermatomyositis and Polymyositis patients with a normal CPK but elevated aldolase are more likely to have a malignancy
Osteochondritis dissecans is a result of chronic microtrauma and represents a form of avascular necrosis that is small and focal.
Pulmonary function tests in interstitial lung disease (ILD) typically show a normal or elevated FEV1/FVC ratio and a decreased DLCO.
Osteomyelitis is seen more than 100X more frequently in sickle cell disease than in normal individuals
Forearm ischemic test: If pyruvate rises but lactate does not, the patient has lactate dehydrogenase-M subunit deficiency
Patients who have cold agglutinin syndrome frequently present with a low-grade autoimmune hemolytic anemia and acrocyanosis.
A deficiency of either C1r or C1s is associated with SLE; these deficiencies generally have prominent renal and cutaneous manifestations.
The anti-synthetase syndrome is marked by myositis, Raynaudâ€™s, ILD, & mechanicâ€™s hands. Most often associated with anti-Jo-1 antibodies.
Osteoporosis: Approximately 1/3 of all vertebral fractures are painful but 2/3 are asymptomatic
Melanonychia, or nail hyperpigmentation, is a well-described reversible adverse effect of cyclophosphamide.
Lofgrenâ€™s syndrome is a form of sarcoidosis & includes the clinical triad of hilar lymphadenopathy, acute polyarthritis, & erythema nodosum.
CRP is usually normal in SLE flares and its elevation may reflect an active infection in a lupus patient with unclear clinical symptoms
The WOMAC is a set of standardized questionnaires used to determine the overall level of disability in patients with OA of the knee and hip.
Whipple's disease is caused by Tropheryma whipplei. Characterized by insidious onset of weight loss, diarrhea, arthralgias, & abdominal pain
Zidovudine induced myopathy causes myalgias, muscle tenderness, proximal muscle weakness, & muscle atrophy. CPK levels are elevated 10 fold.
Pericarditis often presents early in rheumatoid vasculitis. Its development should trigger an evaluation for other hallmarks of vasculitis.
Purpura, hypocomplementemia, and cryoglobulinemia are three key prognostic factors for adverse outcome in primary Sjogren's Syndrome.
Compared to the general population, there is a substantial increase in the male-to-female ratio in children born to women with SLE. #ACR2012
Mi-2 antibodies are seen in patients with â€œclassicâ€ dermatomyositis, including Gottronâ€™s papules, heliotrope rash, & â€œVâ€ and â€œshawlâ€ sign.
Unlike most other diabetic complications affecting the hand, diabetic cheiroarthropathy is painless.
Forearm ischemic test: in CPT II deficiency, both lactate and ammonium rise appropriately thus not a helpful test in the diagnosis
Diabetic cheiroarthropathy is a common complication of diabetes related to increased glycation and nonenzymatic browning of skin collagen.
Isolated patello-femoral compartmental degenerative changes in the knee is an important indicator of CPPD. (submitted pearl - thanks!)
Feltyâ€™s syndrome is characterized by rheumatoid arthritis, splenomegaly and leukopenia with associated recurrent infections.
The incidence of ANA positivity with procainamide is ~90%. With hydralizine, ~50%, and with isoniazid, ~20%
Celiac disease associated arthritis typically involves the lumbar spine, hips, knees, and shoulders and remits with gluten-free diet.
Synovial fluid crystals with a â€œMaltese crossâ€ appearance on light microscopy indicate lipid drops & are suggestive of subchondral fracture.
CD40L (activated T-cells) binding with CD40 (B cells) induces immunoglobulin class switching from IgM to IgG secretory responses in B cells.
Wilson’s dz- autosomal recessive w/ incr copper deposition in brain, liver & joints (<50%) w/ premature OA in wrist, MCPs, knees & spine.l
Consider acid maltase deficiency (Pompe disease) in patients that appear to have polymyositis w/significant respiratory insufficiency
The major cause of malabsorption in scleroderma is intestinal stasis w/ bacterial overgrowth. Patients are commonly managed with antibiotics
The most common infections preceding reactive arthritis are Chlamydia, Salmonella, Shigella, Campylobacter, and Yersinia.
Rheumatoid arthritis can be seen in patients with T-cell large granular lymphocyte leukemia (T-LGL). Presentation is similar to Felty's.
Patrick's test is useful in evaluating pathology of the hip. A positive test can be indicative of a sacroiliac problem but not very reliably
Denosumab is a monoclonal antibody targeted against RANK ligand and is FDA approved for the treatment of osteoporosis.
Familial Mediterranean fever (FMF) patients who are lactose intolerant may develop dose-limiting side effects of colchicine.
Marfan syndrome results from mutations in the fibrillin-1 (FBN1) gene on chromosome 15, which encodes for the glycoprotein fibrillin.
The shingles vaccine may be safe to give to SLE pts who have low disease activity and are on low doses of immunosuppressive meds. #ACR2012
Paresthesia (burning) or hypesthesia (numbness and tingling) over the upper outer thigh is the classic presentation of meralgia paresthetica
Risk factors for the development of mesenteric vasculitis in lupus patients (lupus enteritis) include peripheral vasculitis and CNS lupus.
Belimumab does reduce the number of circulating B cells, but less significantly and durably than anti-CD20 monoclonal antibodies.
MRL/lrp mice (lupus prone) carry a mutation in the Fas gene (affects cellular apoptosis). They develop anti-dsDNA, nephritis, & synovitis.
Methotrexate competitively inhibits dihydrofolate reductase (DHFR), an enzyme that participates in the tetrahydrofolate synthesis.
Tocilizumab is a humanized monoclonal antibody against the interleukin-6 receptor. It is approved for the treatment of rheumatoid arthritis.
Rheumatoid vasculitis in more common in patients who have had severe, destructive RA but whose joints are no longer active (burnt out).
Plaquenil can theoretically reduce the analgesic effect of both codeine and tramadol due to cytochrome P450 2D6 inhibition.
The use of azathioprine & allopurinol together can lead to a severe drugâ€“drug interaction. It is usually better not to use this combination.
Patients with RS3PE (remitting seronegative symmetrical synovitis with pitting edema) have sudden onset polyarthritis and are RF negative.
The calcineurin inhibitors (tacrolimus, cyclosporine) are immunosuppressants which reduce interleukin-2 (IL-2) production by T-cells.
Radiographic signs of Gaucher disease include bone infarcts, osteopenia and â€œErlenmeyer flaskâ€ deformity
Milwaukee Shoulder (apatite-associated destructive arthritis) is the result of peri- or intraarticular deposition of hydroxyapatite crystals
Adult Henoch SchÃ¶nlein Purpura (HSP) patients generally have less abdominal pain and fever, and more joint symptoms and renal involvement.
Rheumatoid arthritis is currently one of the most frequent causes of amyloidosis of the AA type, however the prevalence is declining.
Elevations in ESR due to advanced age or sex can be calculated according to the following equation: ESR(mm/hr) < age (+10 for women) / 2
Interstitial nephritis, manifest as a type 1 renal tubular acidosis, is the most common renal manifestation of SjÃ¶gren's syndrome.
Osteoid osteoma is a solitary benign lesion of bone usually occurring in a long bone cortex. Presents in 2nd or 3rd decade of life.
Amongst the periodic febrile syndromes, responsiveness to colchicine is relatively specific to familial Mediterranean fever (FMF).
Cubital tunnel syndrome is caused by entrapment or irritation of the ulnar nerve in the groove behind the medial epicondyle.
Leflunomide (pregnancy category X) is detectable in plasma up to 3 years after discontinuation. Cholestyramine is given to enhance clearance
Hand deformity in SLE (Jaccoudâ€™s arthropathy) results from ligamentous laxity rather than the destructive synovial pannus of RA.
The most frequent ocular manifestation in patients with Cogan syndrome is interstitial keratitis. Tx is with steroids and immunosupprants
When evaluating a patient for SjÃ¶gren's, ask about dental health as poor dentition is associated with inadequate salivary production.
A febrile patient with HIV and a recent onset of thigh pain and swelling most likely has pyomyositis.
Between 10% and 25% of patients with chronic ITP and a positive ANA develop SLE over time. Higher if AIHA is also present (Evansâ€™syndrome).
Epiphysitis, presenting as a step-like erosion of the anterosuperior angle of the vertebra, is one of the earlier findings in spondylitis.
Osteoporosis: An older patient is more likely to suffer a fracture compared to a younger individual with the same T-score
Two alleles, DRB1*0401 and DRB1*0404, primarily account for the DR4 association with rheumatoid arthritis in Caucasians.
Approximately 33% of lupus patients stop working within 4 years of their diagnosis due to disability.
Ferguson views (plain radiograph) are useful for evaluation of the entire length of the sacroiliac joints symmetrically.
An isolated low DLco (on PFTs) in a patient with scleroderma (especially CREST) suggests pulmonary hypertension.
Superior migration of the humeral head detected by plain radiography indicates a significant rotator cuff tear.
Lupus patients should avoid sulfa-containing antibiotics because of a high incidence of skin rash & other side effects including lupus flare
The DAS28 scale is from 0 to 10. A score above 5.1 means high disease activity (RA) whereas a DAS28 below 3.2 indicates low disease activity
The ANCA-associated vasculitidies (Wegener's, Churg Strauss, & MPA) are all associated with a pauci-immune glomerular nephritis.
Indications for urate lowering therapy include tophaceous gout, erosive changes on xray, nephrolithiasis, & 2 or more gout attacks per year.
Trimethoprim/sulfamethoxazole can enhance the cytotoxic effects of methotrexate because trimethoprim is an antifolate reductase inhibitor.
There are currently 5 FDA approved anti-TNFÎ± agents: infliximab, etanercept, adalimumab, golimumab, and certolizumab pegol.
ALPS (autoimmune lymphoproliferative syndrome) is a disorder of the Fas-Fas ligand pathway that leads to a defect in lymphocyte apoptosis.
Postglucocorticoid hypopigmentation of the skin can be avoided by the injection of air following the medication.
Susac's syndrome is a microangiopathy characterized by the triad of encephalopathy, branch retinal artery occlusions and hearing loss.
Patients with IBD (Crohnâ€™s and UC) spondyloarthritis tend to develop posterior uveitis more commonly than other spondyloarthropathies
"Moyamoya" is a Japanese word meaning obscure, or hazy, like a puff of smoke. Thus, the term is used to denote a vascular collateral network
Pigmented villonodular synovitis is a benign neoplasm that typically presents as an intra-articular tumor. Bloody effusions are common.
Skin biopsy can confirm a diagnosis of calciphylaxis but carries a significant risk of severe pain, poor healing, and superinfection
Diffuse infiltrative lymphocytosis syndrome (DILS) is a disorder that mimics Sjogren's and is seen in HIV patients.
Pseudogout is associated with hypoparathyroidism, hemochromatosis, hypomagnesemia, hypophosphatasia and hypothydroidism.
Pain and/or weakness with isometric testing of shoulder internal rotation suggest pathology in the subscapularis rotator cuff tendon
About 7% of patients with polyarteritis nodosa (PAN) have hepatitis B virus (HBV), but fewer than 1% of patients with HBV develop PAN.
Intrauterine fetal heart block occurs in 2% of pregnant women with anti-Ro/SSA antibodies. Recurrence rate is 16% for subsequent pregnancies
Screening for celiac sprue includes serologic testing with total IgA, IgA tissue transglutaminase or IgA endomysial antibody.
The prevalence of ankylosing spondylitis ranges between 0.1% and 1%, with a male predominance of 2-3:1.
Hypercalcemia occurs in 10% of patients with sarcoidosis and is caused by endogenous production of 1,25 OH Vit D in the sarcoid granuloma.
Up to one-third of lupus patients have one or more additional autoimmune diseases such as Sjogren's or Hashimoto's thyroiditis.
Femoroacetabular impingement syndrome can be a cause of hip pain and premature osteoarthritis in young adults. Refer to an orthopedist.
Plasmacytoid dendritic cells are the major source of type I interferons associated with active systemic lupus erythematosus.
Muscle sxs w/ prolonged low-intensity exercise are/or prolonged fasting suggests a defect in fatty acid oxidation (CPT II def most common)
Lupus nephritis occurs twice as frequently in African Americans with SLE than compared to Caucasians with SLE.
The most common sites for finding radiographic chondrocalcinosis are the knees, triangular fibrocartilage of the wrists, & pubic symphysis.
In ankylosing spondylitis, inflammation has a predilection for fibrocartilaginous sites rich in aggrecans and type II collagen.
Osteoporosis: For each vertebral fracture, there can be a decrease in FVC by 9%, reducing pulmonary function significantly
I patients with lupus, the presence of an anticardiolipin antibody can cause a false positive test for syphilis (RPR).
Familial CPPD is associated with a gain of function of the ANKH gene product, leading to increased extracellular pyrophosphate.
The presence of HLA-B5 is associated with BehÃ§et's disease, ulcerative colitis, and polycystic kidney disease.
Alport's syndrome is a default in type IV collagen which effects the basement membrane.
McArdleâ€™s disease is the most common glycogen storage disease. Most patients have an elevated CK level and have myopathic changes on EMG.
Urticarial lesions persisting for more than 48 hours are more likely to be related to an underlying vasculitis.
Lupus pernio is a chronic raised indurated skin lesion associated with sarcoidosis. It has nothing to do with either lupus or pernio.
Polyarteritis nodosa (PAN) can be associated with hepatitis B. Classic PAN usually manifests within the first 6 mo of hepatitis B infection
Celiac disease is associated with arthritis in ~9% of patients. Typically nonerosive and usually responds to a gluten free diet.
B Lymphocye Stimulator (BLyS) levels are higher in SLE patients who present at a younger age and predict damage accumulation. #ACR2012
In children, Henoch SchÃ¶nlein Purpura (HSP) is usually benign and self-limiting, however in adults, can be severe with worse outcomes.
In patients with RS3PE who donâ€™t respond to low dose prednisone, consider the possibility of an underlying malignancy.
The presence of anti-SRP antibody is assoc with severe, steroid resistant polymyositis, muscle pain from necrosis, & cardiac involvement
Lupus patients with nephrotic syndrome are at increased risk for venous thrombosis, particularly deep vein and renal vein thrombosis.
Anti-TIF1-gamma autoantibody positive dermatomyositis patients carry an increased risk for internal malignancies.
Palindromic rheumatism - episodic inflammation in usually 2 to 3 joints, large joints commonly. There is no joint damage after attacks.
SLE patients with subacute cutaneous lupus erythematosus (SCLE) generally have mild disease with a low incidence of nephritis & arthritis.
Sparing of the epidermis and presence of mucin deposits differentiate scleromyxedema (lichen myxedematosus) from scleroderma and morphea.
The allopurinol hypersensitivity syndrome consists of rash, fever, hepatitis, eosinophilia, and renal failure. Mortality approaches 25%.
Trigger finger (aka stenosing flexor tenosynovitis) is noninfectious inflammation of the flexor tendon sheath of the finger (or thumb).
Up to 10% of patients with biopsy proven GCA can have a normal ESR. Systemic manifestations are more common in those with high ESRs.
Posterior interosseous neuropathy is a cause of lateral elbow pain and hand weakness and can be a complication of rheumatoid arthritis.
Osteoporosis accounts for approximately 1.5 million fractures in the United States each year
Patients with ANCA negative Churg-Strauss syndrome are more likely to have cardiac and parenchymal lung disease.
Cogan's syndrome hallmarks include interstitial keratitis and vestibuloauditory dysfunction. It is most commonly seen in young adults.
Spondyloarthropathy occurs in ~ 20% of patients with inflammatory bowel disease. Occurs more often in Crohnâ€™s than in ulcerative colitis.
Th1 cells secrete IL-2 & interferon gamma (cell-mediated immunity). Th2 cells secrete IL-4, IL-5, IL-6, IL-10, & IL-13 (humoral immunity).
Osgoodâ€“Schlatter syndrome (tibial tubercle apophyseal traction injury) is an irritation of the patellar ligament at the tibial tuberosity
28% of SLE adult patients may carry an underlying primary immunodeficiency. #ACR2012
Up to 15% of patients with chondrocalcinosis will be found to have primary hyperparathyroidism
SAPHO syndrome is an inflammatory bone disorder assoc w/ skin changes. It stands for Synovitis, Acne, Pustulosis, Hyperostosis, & Osteitis.
In pregnant SLE patients who are flaring, starting azathioprine may not be all that effective. Better when started before. Pred still best.
Respiratory involvement (glottis or tracheobronchial tree) is a frequent finding in relapsing polychondritis and is the main cause of death.
IL-23, along with IL-1 and IL-6, drive the differentiation of Th17 cells. Th17 cells are defined by the production of the cytokine IL-17
Cochicine-induced axonal neuromyopathy most commonly occurs when renal dysfunction is present, but it is reversible not permanent.
Radiographic osteoarthritis is at least twice more common than symptomatic osteoarthritis
Osteopetrosis is caused by an osteoclast proton pump deficiency resulting in a failure of bone resorption while its formation persists.
Young children with oligoarticular onset, ANA positive, JIA should be screened every three to four months for uveitis.
Undifferentiated connective tissue diseases and â€œincomplete lupusâ€ represent up to 10â€“20% of patients referred to rheumatologists.
Overgrowth causing limb length inequality is the second most frequent complication of oligoarticular JIA (uveitis is the most common).
Consider phosphofructokinase deficiency (Tarui disease) in patients w/ exercise induced muscle sxs, elevated CK, and hemolytic anemia
Patients with â€œrhupusâ€ have an overlap syndrome with clinical and serologic signs of both SLE and RA, including radiographic erosions.
A shorter disease duration and younger age are predictors of a major clinical response to TNF blockers in active ankylosing spondylitis
The DAS28 is an index of RA disease activity. Calculated using a 28 tender & swollen joint count, ESR (or CRP), & patient global health VAS.
Discoid lesions in children and adolescents are likely secondary to SLE, not to isolated discoid lupus.
Hydroxyurea is the most commonly reported medication to induce drug-induced dermatomyositis (50-70% of case reports).
In patients with psoriasis, nail changes have the strongest association with arthropathy, particularly affecting the DIP joints.
Anti-DNA cross reacting w/ brainstem neuronal receptors induce apoptosis & cause preferential loss of female fetuses in murine SLE. #ACR2012
Infection with parvovirus B19 has been associated with symmetrical polyarthralgia/ polyarthritis which can mimic rheumatoid arthritis.
Adhesive capsulitis (shoulder) is characterized by restricted range of motion (active AND passive) and nocturnal pain.
Mixed connective tissue disease (MCTD) (aka Sharp Syndrome) was first described in 1972 by Gordon C. Sharp and colleagues.
Patients with primary SjÃ¶grenâ€™s syndrome and hypocomplementemia, particularly C4, are at increased risk for the development of lymphoma.
Neuropathic arthropathy of hands & wrists due to cervical syringomyelia can result in articular deformities resembling rheumatoid arthritis
Although controversial, the frequency of autoimmune thyroiditis (Hashimoto's) is reportedly increased in those with SjÃ¶gren's syndrome.
Survival in SLE has improved significantly, but patients still have 3-5 times increased mortality compared to the general population.
In women, the estimation of the upper limit of normal for the ESR is: ESR <= (age[yrs] + 10) / 2. For men: ESR <= age[yrs] / 2.
Lupus erythematosus tumidus (LE tumidus) is characterized by smooth, erythematous plaques on sun-exposed areas without surface changes.
In psoriatic arthritis, a CRP >0.9 md/dl at diagnosis may predict an inadequate response to conventional DMARDS. #ACR2012
Patients with HCV can have systemic vasculitis manifestations of polyarteritis nodosa type or mixed cryoglobulinemia type.
Weber-Christian disease (relapsing febrile nodular panniculitis) is an inflammatory infiltration of subcutaneous adipose tissue.
The leading cause of death in patients with diffuse systemic sclerosis is interstitial lung disease.
Pleural effusions in RA are exudates, with high protein and LDH levels & very low glucose. In contrast to empyemas, lymphocytes predominate.
The target uric acid level for a patient with tophaceous gout is <4.0 mg/dL (compared to non-tophaceous gout where the target is <6.0 mg/dL)
The majority of African-Americans with rheumatoid arthritis do not carry the shared epitope in their DR genes (in contrast to Caucasians).
Drug reaction w/ eosinophilia & systemic symptoms (DRESS) is notable for a long latency (2 â€“ 8 wks) between drug exposure and disease onset
Dupuytren's contracture is progressive fibrosis of the palmar fascia resulting in contractures of one or more fingers at the MCP joints.
Four forms of vasculitis which commonly cause bruits: Takayasuâ€™s arteritis, giant cell arteritis, Behcetâ€™s disease, and Coganâ€™s syndrome.
Acquired factor VIII inhibitor (aka acquired hemophilia A) is a complication of severe rheumatoid arthritis and systemic lupus erythematosus
10â€“20% of patients with SjÃ¶grenâ€™s syndrome have anti-thyroglobulin antibodies and may go on to develop autoimmune thyroiditis.
Chilblain lupus is a cold-induced microvascular injury, initially resembling chilblains but eventually assumes the form of discoid lupus.
Erythema nodosum and peripheral arthritis are both more common in Crohn's disease than ulcerative colitis.
Diplopia caused by ischemia of extraocular muscles, cranial nerves, or the brainstem may be a feature of GCA in up to 15% of patients.
Neuropathic joints occur in 25% of patients with syringomyelia. The most common joint is the shoulder with about 80% occurrence.
Sudden flank pain and worsening proteinuria in a lupus patient with known glomerulonephritis should be assessed for renal vein thrombosis.
Class IV lupus nephritis (diffuse proliferative) is the renal lesion associated with the highest morbidity and mortality for lupus patients.
Forearm ischemic test: If lactate rises but ammonia does not - patient has myoadenylate deaminase deficiency
Reactive arthritis appears to be triggered by CD8+ T cells responding to peptides derived from bacteria which are bound to HLA-B27.
Chilblain lupus is a rare variant of discoid lupus. Lesions are tender, purplish nodules often affecting the fingers, ears, calves, & heels
The first animal model of systemic lupus erythematosus was the F1 hybrid New Zealand Black/New Zealand White mouse.
The sensitivity and specificity of anti-CCP reactivity for the diagnosis of rheumatoid arthritis is 74.0% and 94.5%, respectively.
In patients with BehÃ§et's disease who present with severe headache and ocular pain, evaluate for cerebral venous thrombosis.
Patients on steroids fracture at a higher T-score than do patients with other types of osteoporosis
Flexor hallucis longus tendinopathy, commonly known as dancer's tendinopathy, commonly is found among dancers, especially ballet dancers.
Interdigital neuritis, or Mortonâ€™s neuroma, occurs most commonly in the web space between the third and fourth toes.
Dural ectasia is a common cause of low back pain and radicular pain in patients with Marfan syndrome.

There are currently 368 rheumatology pearls in the database.
The lastest pearl was added October 30, 2020

Welcome to Rheumatology Pearls

This site is a rather simple educational exercise in the distribution of medical "pearls of wisdom" about rheumatology. There are currently 368 pearls in the database which cover a variety of rheumatologic topics including clinical diagnosis, laboratory tests, genetics, basic science and medications. The pearls are each 140 characters or less and thus are "tweetable" and allow for experimentation in micro-blogging and medical education. There is twitter feed associated with this website @RheumPearls.

The pearls themselves are written by Dr. Christopher Collins M.D., a Rheumatologist at the Washington Hospital Center in Washington DC, and new pearls are added frequently. If you notice an error with one of the pearls, please let us know. Additionally, if you have a rheumatology pearl you would like to submit, send it to us here.