66: Rheumatoid Arthritis, Juvenile Idiopathic Arthritis, Adult-Onset Still Disease, and Rheumatic Fever Flashcards
What is rheumatoid arthritis (RA) and its primary characteristics?
Rheumatoid arthritis (RA) is a systemic inflammatory autoimmune disease characterized by debilitating chronic, symmetric polyarthritis. It often leads to joint function limitation, decline in functional status, and possibly premature death. Permanent remission is unusual.
What are the common extraarticular manifestations of rheumatoid arthritis?
Common extraarticular manifestations of rheumatoid arthritis include:
- Rheumatoid nodules
- Pyoderma gangrenosum
- Granulomatous and other skin lesions
- Vasculitis
- Internal organ involvement
What is the prevalence of rheumatoid arthritis in the adult population?
The prevalence of rheumatoid arthritis is approximately 0.4% to 1% of the adult population, with 0.4 per 1000 in females and 0.2 per 1000 in males. The peak onset is around 50 years of age.
What are the typical locations for rheumatoid nodules in patients with RA?
Rheumatoid nodules typically occur over pressure points such as:
- Olecranon
- Extensor surface of the forearms
- Achilles tendon
They have also been described in almost every location, including viscera.
What are the main histologic findings associated with rheumatoid nodules?
The main histologic findings associated with rheumatoid nodules include:
- Palisaded granulomas in the deep dermis or subcutaneous tissues with fibrinoid degeneration of collagen
- Multitude of neutrophils and neutrophilic dust
- Surrounding fibrosis
- Proliferation of vessels
What complications can arise from rheumatoid nodules?
Complications that can arise from rheumatoid nodules include:
- Ulceration
- Infection
- Joint effusion (rheumatoid chyliform bursitis)
- Fistulas (fistulous rheumatism)
What is rheumatoid nodulosis and its characteristics?
Rheumatoid nodulosis refers to the development of rheumatoid nodules in patients without chronic synovitis or radiographic findings, and with mild or no systemic manifestations. It predominantly involves men, and many individuals with rheumatoid nodulosis may develop frank rheumatoid arthritis (RA).
A patient with RA develops symmetric, skin-colored papules on the elbows. What is the likely diagnosis?
The likely diagnosis is Rheumatoid Nodules, the most common dermatologic finding in RA.
What are the characteristics of Pseudorheumatoid nodulosis?
- Similar lesions seen in children
- Distribution differs by localizing over the tibia, dorsal foot, or scalp
- May be large but no systemic disease nor positive serology
- Most regress within 2 years
- Progression to RA is extremely rare
What are the two types of Methotrexate-related cutaneous reactions?
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Accelerated Nodulosis
- Low-dose methotrexate may precipitate erythema and enlargement of preexisting rheumatoid nodules.
- Regression is expected when the methotrexate dose is decreased or discontinued.
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Papular Reaction to Methotrexate
- Syndrome of clustered, erythematous, indurated papules, commonly on proximal extremities and buttocks.
- Reported in patients with RA and other diseases, especially collagen vascular diseases.
What is the presentation and treatment for Palisaded neutrophilic and granulomatous dermatitis (PNGD)?
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Presentation:
- Symmetric skin-colored to erythematous smooth, umbilicated, or crusted papules.
- Primarily on elbows and extremities (51% upper, 27% lower, 21% trunk, head, neck).
- Less common presentations include urticarial plaques, erythematous nodules, and annular papules.
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Treatment:
- Directed at underlying disease.
- Stop TNF inhibitors and allopurinol.
- Intralesional corticosteroids, NSAIDs, Dapsone, Colchicine, Systemic corticosteroids, Oral tacrolimus, TNF inhibitors.
- Topical therapy is generally NOT effective.
What are the characteristics of Interstitial granulomatous dermatitis (IGD)?
- Also known as IGD with arthritis, linear subcutaneous bands of RA, and Ackerman syndrome.
- Associated with several disorders, including RA.
- Usually asymptomatic.
- Presents symmetrically on the lateral upper trunk and proximal inner arms and thighs, occasionally on buttocks, abdomen, breast, and umbilicus.
- Other morphologic presentations include erythematous to violaceous patches or plaques, diffuse macular erythema, and annular lesions.
A patient with RA develops erythematous, indurated papules on the proximal extremities. What is the likely diagnosis?
The likely diagnosis is Methotrexate-Related Papular Reaction, which can occur in RA patients treated with methotrexate.
What are the histopathologic findings associated with IGDR?
- Dense, diffuse infiltrate of histiocytes arranged in a band-like configuration in the middle or deep reticular dermis.
- Foci of basophilic collagen surrounded by palisaded histiocytes.
- Scattered mitotic figures are readily seen.
- Neutrophils and eosinophils may be present, notably in areas of degenerated collagen.
- Variably dense interstitial CD68+ epithelioid histiocytes often surround foci of abnormal collagen, cleaving away altered collagen and histiocyte section (‘floating sign’).
- Vasculitis is usually absent.
- Lymphocytes abutting epidermis with basal vacuolization is rarely seen, which may distinguish IGDR from pure IGD.
- Mucin deposition is minimal or absent.
What are the commonly implicated drugs associated with IGDR?
- Furosemide
- ACEIs
- TNF inhibitors
- Soy
What are the clinical features of Rheumatoid Neutrophilic Dermatosis?
- Very rare cutaneous manifestation in patients with severe RA.
- Usually chronic.
- Erythematous and urticaria-like plaques and papules that are sharply marginated.
What histopathological features are observed in Autoimmune Neutrophilic Dermatoses Syndrome?
- Interstitial and perivascular neutrophilic infiltrate with leukocytoclasia without vasculitis.
- Vacuolar alteration at the dermal–epidermal junction.
What is the treatment approach for patients with drug-induced skin reactions?
- Stopping any causative drug and treating the underlying disease.
A patient presents with erythematous, umbilicated papules primarily on the elbows and extremities. What is the likely diagnosis and treatment approach?
The likely diagnosis is Palisaded Neutrophilic and Granulomatous Dermatitis (PNGD). Treatment involves addressing the underlying disease, stopping TNF inhibitors and allopurinol, and using intralesional corticosteroids, NSAIDs, dapsone, colchicine, or systemic corticosteroids. Topical therapy is generally not effective.
A patient with RA develops erythematous, urticaria-like plaques and papules. What is the likely diagnosis?
The likely diagnosis is Rheumatoid Neutrophilic Dermatosis, a rare cutaneous manifestation in patients with severe RA.
A patient with RA presents with erythematous nodules and papules on the extremities. What is the likely diagnosis?
The likely diagnosis is Palisaded Neutrophilic and Granulomatous Dermatitis (PNGD), which can present with erythematous nodules and papules.
A patient with RA develops erythematous plaques on the trunk and extremities. What is the likely diagnosis?
The likely diagnosis is Interstitial Granulomatous Dermatitis (IGD), which is associated with RA.
A patient with RA develops erythematous, urticaria-like plaques. What is the likely diagnosis?
The likely diagnosis is Autoimmune Neutrophilic Dermatoses Syndrome, which produces urticarial lesions in association with RA.
What is the primary environmental risk factor for rheumatoid vasculitis in male seropositive patients?
Smoking is the most consistently demonstrated environmental risk factor for rheumatoid vasculitis, particularly in male seropositive patients.
What are the constitutional symptoms that herald the onset of rheumatoid vasculitis?
The onset of rheumatoid vasculitis is often heralded by constitutional symptoms such as:
1. Fever
2. Weight loss
3. Increased ESR and/or CRP
4. Thrombocytosis
5. Anemia of chronic disease
What is the most common presentation of rheumatoid vasculitis?
Cutaneous vasculitis is the most common presentation of rheumatoid vasculitis, followed by vasculitic neuropathy.
What is the relationship between TNF-inhibitor therapy and rheumatoid vasculitis?
TNF-inhibitor therapy is associated with both the onset and improvement of rheumatoid vasculitis.
What are the characteristics of pyoderma gangrenosum in patients with rheumatoid arthritis?
Pyoderma gangrenosum is suspected if deep liquefying ulcers with a characteristic purple, undermined border occur in patients with RA. It may occur at any site but is most common on the lower extremities and abdomen, occurs more frequently and severely in females, and may take years to heal.
What are some other vasculitis syndromes described in patients with rheumatoid arthritis?
Other vasculitis syndromes described in patients with RA include:
- Cryoglobulinemic vasculitis
- Erythema elevatum diutinum
- Benign cutaneous polyarteritis nodosa
- Livedo vasculitis (segmental hyalinizing vasculitis/atrophie blanche)
- Reactive angioendotheliomatosis
What is the typical age and duration of rheumatoid arthritis at presentation for patients with rheumatoid vasculitis?
The median age of participants at presentation for rheumatoid vasculitis is 63 years, and the median duration of rheumatoid arthritis is 10.8 years.
What histopathologic findings are associated with rheumatoid vasculitis?
Histopathologic exam findings in rheumatoid vasculitis include:
- Mononuclear or neutrophilic infiltration of the vessel walls
- Elements of vessel wall destruction (necrosis, leukocytoclasis, and disruption of the elastic laminae)
A patient with RA develops deep liquefying ulcers with a purple undermined border on the lower extremities. What is the likely condition, and what is its association with RA?
The condition is Pyoderma Gangrenosum, which is a vascular manifestation associated with RA. It is suspected when such ulcers occur in RA patients.
A patient with RA presents with indurated erythema and papules over the elbows. What is the likely condition, and what therapy is associated with its onset and improvement?
The condition is Intravascular or Intralymphatic Histiocytosis. TNF-inhibitor therapy is associated with both the onset and improvement of this condition.
A patient with RA presents with a history of smoking and develops cutaneous vasculitis. What are the risk factors and histopathologic findings associated with rheumatoid vasculitis?
Risk factors include male gender, smoking, and seropositivity to rheumatoid factor and citrullinated peptides. Histopathologic findings include mononuclear or neutrophilic infiltration of vessel walls, necrosis, leukocytoclasis, and disruption of elastic laminae.
A patient with RA develops deep ulcers with a purple undermined border on the abdomen. What is the likely diagnosis, and what is its prognosis?
The likely diagnosis is Pyoderma Gangrenosum. It may take years to heal and occurs more frequently and severely in females.
What are the characteristic deformities associated with rheumatoid arthritis?
- Radial deviation of the hand with ulnar deviation of the digits
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Swan neck deformity:
- Hyperextension of PIP
- Flexion of DIP
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Boutonniere deformity:
- Flexion of PIP
- Extension of DIP
What is the significance of anticitrullinated protein antibodies (ACPAs) in rheumatoid arthritis?
- ACPAs are highly specific for RA.
- Found in ~50% of early RA patients.
- Predicts disease severity and radiologic damage.
- Used as a biomarker for patients with a more severe disease phenotype to target for aggressive treatment.
What is the significance of anticitrullinated protein antibodies (ACPAs) in rheumatoid arthritis?
ACPAs are highly specific for RA. Found in ~50% of early RA patients. Predicts disease severity and radiologic damage. Used as a biomarker for patients with a more severe disease phenotype to target for aggressive treatment.
What role does carbamylation play in rheumatoid arthritis?
Carbamylation involves the conversion of lysine to homocitrulline. Smoking can enhance carbamylation, especially during chronic inflammation. Antibodies to carbamylated proteins are found in both ACPA+ and ACPA− RA patients.
What are some differential diagnoses (DDx) for rheumatoid arthritis?
Viral syndromes (parvovirus B19, rubella, hepatitides B and C), Psoriatic arthritis, Polymyalgia rheumatica, Remitting seronegative symmetric synovitis with pitting edema, Palindromic rheumatism, Adult Still disease, Systemic lupus erythematosus, Gout, Multicentric reticulohistiocytosis, Leprosy.
What is the heritability of rheumatoid arthritis and its associated genetic factors?
Twin studies show heritability of RA to be 60%. More than 100 genetic loci are associated with RA. The most important locus is in the HLA class II region, specifically the HLA-DRB1 molecule, which is linked to the risk of progressing from ACPA+ to ACPA+ RA.
What is the significance of rheumatoid factor in diagnosing rheumatoid arthritis?
Rheumatoid factor is an autoantibody that reacts with the Fc portion of immunoglobulin G, found in 85% of patients with RA. However, it has a specificity of 23 to 94% and can also be present in other diseases, making it not definitive for RA diagnosis.
How do anti-citrullinated protein antibodies (ACPAs) compare to rheumatoid factor in terms of specificity for rheumatoid arthritis?
ACPA is a more specific marker than rheumatoid factor, particularly in early disease, where its specificity ranges from 94 to 100%.
What role does ultrasonography play in the assessment of rheumatoid arthritis?
Ultrasonography provides increased sensitivity compared to standard clinical examinations, allowing for detailed information about the synovial membrane, tendons, cartilage, bursae, and cortical bones, and helps detect intraarticular and periarticular inflammatory processes.
What are the first-line treatment strategies for rheumatoid arthritis?
First-line treatment strategies for RA include Methotrexate, unless contraindicated. If contraindicated, alternatives like leflunomide or sulfasalazine are suggested. Short-term glucocorticoids may also be considered when initiating or changing conventional DMARDs.
What are the recommendations for managing rheumatoid arthritis according to the European League Against Rheumatism?
The recommendations include: 1. Rheumatologists should primarily care for patients with RA. 2. Treatment decisions should be shared with the patient. 3. Decisions should be based on disease activity, progression of structural damage, comorbidities, and safety issues. 4. DMARDs should be started as soon as the diagnosis is made, aiming for sustained remission or low disease activity.
What are the potential treatment options for rheumatoid vasculitis in RA patients?
Treatment options for rheumatoid vasculitis include: Hydroxychloroquine and low-dose aspirin to reduce the odds of developing vasculitis. Cyclophosphamide and biologics, although treatment remains difficult. High relapse and mortality rates are noted, with 5-year mortality rates ranging from 26% to 60%.
What are the classification criteria for rheumatoid arthritis according to the 2010 ACR/EULAR guidelines?
The classification criteria for rheumatoid arthritis (RA) include: A. Joint Involvement: 1 large joint (0), 1 to 3 small joints (1), 4-10 small joints (2), >10 joints (5). B. Serology: Negative RF and negative ACPA (0), RF or low-positive ACPA (2), High-positive RF or high-positive ACPA (3). C. Acute-phase reactants: Normal CRP and normal ESR (0), Abnormal CRP or abnormal ESR (1). D. Duration of symptoms: <6 weeks (0), ≥6 weeks (1). A total score of ≥6/10 is needed for definite RA classification.
What are the criteria for diagnosing systemic juvenile idiopathic arthritis (sJIA)?
The criteria for diagnosing sJIA include: Arthritis accompanied or preceded by a documented quotidian fever of at least 2 weeks duration, plus at least 1 of the following: Characteristic rash, Generalized symmetrical lymphadenopathy, Enlargement of liver or spleen, Serositis (pericarditis, pleural or pericardial effusion, rarely peritonitis).
What are the cutaneous findings associated with systemic juvenile idiopathic arthritis (sJIA)?
The cutaneous findings associated with sJIA include: Classic sJIA eruption: very transient salmon pink mostly macular eruption coincident with febrile episodes, indistinguishable from urticaria but not pruritic. The eruption is identical to that seen in adult-onset Still disease, but different cutaneous presentations have been recognized in adult-onset Still disease.
What is the epidemiology of systemic juvenile idiopathic arthritis (sJIA)?
The epidemiology of sJIA includes: European incidence: 2 to 20 per 100,000, North American incidence: 16 to 150 per 100,000, sJIA accounts for 5% to 15% of children with JIA in North America and Europe, Incidence decreased among females, A cyclic pattern of incidence observed, with peaks approximately every 10 years.
What are the noncutaneous findings associated with enthesitis-related arthritis in juvenile idiopathic arthritis?
The noncutaneous findings associated with enthesitis-related arthritis include: Usually affects boys older than age 6 years with lower-limb asymmetrical arthritis associated with enthesitis. Can develop inflammatory lumbosacral pain and are at risk of developing acute anterior uveitis. Approximately 2/3 of patients have persistent disease. Poorer prognosis factors include hip or ankle arthritis, family history of spondyloarthropathy, and polyarticular joint involvement at onset.
What is macrophage activation syndrome and its association with systemic juvenile idiopathic arthritis (sJIA)?
Macrophage activation syndrome (MAS) is: A secondary or acquired form of hemophagocytic lymphohistiocytosis (HLH). A potentially life-threatening complication of rheumatic disorders, most commonly associated with sJIA and adult-onset Still disease. Occurs in roughly 10% of children with sJIA, but may be partially expressed in as high as 30% to 40%.
A 10-year-old boy presents with arthritis, fever, and a salmon-pink macular rash that appears with fever spikes. What is the likely diagnosis, and what are the diagnostic criteria?
The likely diagnosis is Systemic Juvenile Idiopathic Arthritis (sJIA). Diagnostic criteria include arthritis accompanied or preceded by a quotidian fever of at least 2 weeks duration, plus at least one of the following: characteristic rash, generalized symmetrical lymphadenopathy, hepatosplenomegaly, or serositis.
A patient with sJIA presents with arthritis and a salmon-pink macular rash. What is the typical pattern of fever associated with this condition?
The typical fever pattern in sJIA is intermittent, with 1 or 2 daily spikes up to ≥39°C (102.2°F), followed by a rapid return to baseline.
A patient with sJIA develops arthritis and a salmon-pink rash. What are the systemic features that may accompany this condition?
Systemic features of sJIA include fever, generalized symmetrical lymphadenopathy, hepatosplenomegaly, and serositis (e.g., pericarditis, pleural effusion).
A patient with sJIA develops arthritis and a salmon-pink rash. What is the typical pattern of the rash?
The salmon-pink rash in sJIA is evanescent, appearing with fever spikes and disappearing as the fever subsides.
What are the heralding clinical manifestations of systemic juvenile idiopathic arthritis (sJIA)?
The heralding clinical manifestation of sJIA is a change in the fever pattern from intermittent spikes to a continuous high level. Other manifestations may include hepatosplenomegaly, generalized lymphadenopathy, CNS dysfunction (such as lethargy, irritability, disorientation, headache, seizures, or coma), skin or mucosal hemorrhage, and heart, lung, and kidney failure in the sickest patients.
What laboratory findings are associated with macrophage activation syndrome (MAS) in systemic juvenile idiopathic arthritis (sJIA)?
Laboratory findings associated with MAS in sJIA include: Cytopenia, Abnormal liver function tests, Prolonged prothrombin PT and PTT, Serum ferritin levels ranging from 5000 to 10,000 ng/mL.
What are the proposed guidelines for the classification of MAS in sJIA?
The proposed guidelines for the classification of MAS in sJIA include: A febrile patient with known or suspected sJIA who has a ferritin value >684 ng/mL, and exhibits any 2 of the following: 1. Platelet count ≤ 181 × 10^9/L, 2. Aspartate aminotransferase >48 units/L, 3. Triglycerides >156 mg/dL, 4. Fibrinogen ≤ 360 mg/dL.
What are the treatment options for systemic juvenile idiopathic arthritis (sJIA)?
Treatment options for sJIA include: NSAIDs: Short-term monotherapy, not disease-modifying. Intraarticular corticosteroid injections: Frequently used, particularly in oligoarthritis. Methotrexate: Most widely used conventional DMARD. Leflunomide: Similar effectiveness to MTX, but less experience in children. Systemic glucocorticoids: For severe extraarticular manifestations. TNF inhibitors: Increasingly used, but none are yet approved for treating JIA.
What is the significance of HLA DRB1:11 in systemic juvenile idiopathic arthritis (sJIA)?
HLA DRB1:11 is associated with systemic juvenile idiopathic arthritis (sJIA) and indicates a potential genetic predisposition to the disease. It is part of the etiology and pathogenesis of JIA, suggesting familial links and risk factors for autoimmunity.
A patient with a history of sJIA develops continuous high fever, hepatosplenomegaly, and CNS dysfunction. Lab tests show ferritin >5000 ng/mL and cytopenia. What is the likely complication, and how is it diagnosed?
The likely complication is Macrophage Activation Syndrome (MAS). Diagnosis involves a febrile patient with known or suspected sJIA, ferritin >684 ng/mL, and any two of the following: platelet count ≤181 × 10^9/L, AST >48 units/L, triglycerides >156 mg/dL, or fibrinogen ≤360 mg/dL.
A patient with sJIA develops hepatosplenomegaly, CNS dysfunction, and skin hemorrhage. Lab tests show ferritin >5000 ng/mL. What is the likely complication, and what is the treatment?
The likely complication is Macrophage Activation Syndrome (MAS). Treatment includes high-dose corticosteroids, cyclosporine, and IL-1 inhibitors. Etoposide may be used for resistant cases.
What are the classical cutaneous findings associated with adult-onset Still disease (AOSD)?
Classical cutaneous findings in AOSD include: Salmon-colored, mostly macular and evanescent eruption, Skin involvement in 60% to 70% of cases, more common in febrile presentation. Most characteristically occurs on: Abdomen, Chest, Extensor surfaces of the arms. Rash consists of discrete pink to red macules or slightly edematous papules ranging in size from 5 to 10 mm. Relatively fixed in shape and site during daily eruption, seldom itchy. Koebner phenomenon may be observed.
What are the clinical features and common symptoms of adult-onset Still disease (AOSD)?
The clinical features of AOSD include: High fever of unknown origin exceeding 39°C, presenting in most patients. Classically, patients experience 1 to 2 daily fever spikes above 39°C (102.2°F) in the afternoon or evening. Frequency of symptoms (in descending order): 1. Fever (93%), 2. Arthralgia (90%), 3. Rash (70%), 4. Sore throat (64%), 5. Lymphadenopathy/splenomegaly (53%), 6. Hepatomegaly (39%), 7. Pericarditis (13%). Myalgia reported in 35% to 44% of patients. Disease course can be: Monocyclic (24% to 30%), Polycyclic (41% to 44%) with intermittent episodes, Chronic articular (26% to 36%).
What are the atypical cutaneous presentations observed in adult-onset Still disease (AOSD)?
Atypical cutaneous presentations in AOSD include: 87% female, ages 8 to 83 years, with 64% from East Asia. Atypical features often present in addition to the typical rash, with 30% to 43% having only atypical manifestations. Most reported atypical presentation includes: Persistent, pruritic papules and plaques (present in 75% of patients), Pruritic 87% of the time. Rarely seen in systemic juvenile idiopathic arthritis (sJIA). May develop fine scale. Commonly located on trunk, extremities, head, and/or neck. Koebner phenomenon observed, either erythematous or brown, and less commonly violaceous. Multiple morphology or distribution patterns observed, with most commonly involved areas being the back.
What are the most reported atypical manifestations of Adult-Onset Still Disease (AOSD)?
The most reported atypical manifestations include persistent, pruritic papules and plaques, present in 75% of patients, and pruritic 87% of the time.
Where are atypical manifestations commonly located in AOSD?
Atypical manifestations are commonly located on the trunk, extremities, head, and/or neck.
What phenomenon is observed in atypical presentations of AOSD?
The Koebner phenomenon is observed, which can be either erythematous or brown, and less commonly violaceous.
What are the major criteria for diagnosing Adult-Onset Still Disease (AOSD) according to Yamaguchi criteria?
The major criteria include:
1. Fever ≥39°C (102.2°F) lasting for 1 week or more
2. Arthralgia lasting 2 weeks or more
3. Typical skin rash: maculo-papular, nonpruritic, salmon-pink rash with concomitant fever spikes
4. Leukocytosis ≥10,000/mm³ with neutrophil polymorphonuclear count ≥80%.
What are the complications associated with Adult-Onset Still Disease (AOSD)?
Two serious complications are reactive hemophagocytic syndrome (2.85% to 6%) and thrombotic thrombocytopenic purpura. AOSD is also associated with malignancy.
What laboratory findings are commonly associated with Adult-Onset Still Disease (AOSD)?
Common findings include leukocytosis in 85% of patients, increased CRP in 93%, increased ESR in 85%, increased hepatic enzymes in 62%, thrombocytosis in 46%, anemia <10 g/dL in 50%-75%, and increased serum ferritin in 56.4%.
What are the red flags in hematologic malignancies associated with Adult-Onset Still Disease (AOSD)?
Red flags include elevated lactate dehydrogenase levels, atypical cells in the blood count, and increased soluble IL-2 receptor levels.
What is the significance of serum ferritin levels in the diagnosis of Adult-Onset Still Disease (AOSD)?
Very high serum ferritin levels combined with low glycosylated ferritin are strongly suggestive of AOSD.
What is the treatment approach for myocarditis in AOSD?
Myocarditis in AOSD is treated with corticosteroids and other immunomodulatory drugs.
What are the treatment options for chronic disease in inflammatory conditions?
For chronic disease, biologic agents such as anti-TNF agents, Anakinra, Rituximab, Tocilizumab, and Canakinumab are sometimes used as first-line therapy.
What are the typical features of subcutaneous nodules associated with acute rheumatic fever?
Subcutaneous nodules are typically less than 2 cm, firm, painless, mobile, and localize over extensor surfaces. They may last for up to 2 weeks.
What are the major clinical features of rheumatic fever?
The major clinical features include migratory polyarthritis, carditis, chorea, erythema marginatum, and subcutaneous nodules.
What is acute rheumatic fever and what typically triggers it?
Acute rheumatic fever is an inflammatory response to group A streptococcal infection, typically occurring 2 to 3 weeks after a throat infection.
What is the typical age range for most cases of acute rheumatic fever?
Most cases occur in children ages 5 to 15 years, but it may occasionally occur in young adults.
What is the initial treatment approach for acute rheumatic fever?
Treatment is directed at eradicating group A β-hemolytic streptococci from the oropharynx, often using Phenoxymethylpenicillin.
What is the clinical appearance of erythema marginatum in rheumatic fever?
Erythema marginatum appears as evanescent, erythematous patches in annular or serpiginous configuration, typically sparing the face.
What is the classic cutaneous presentation of juvenile idiopathic arthritis?
The classic cutaneous presentation is a transient, salmon pink macular eruption that coincides with febrile episodes.
What are the characteristics of pyoderma gangrenosum associated with rheumatoid arthritis?
Pyoderma gangrenosum presents as deep, liquefying ulcers with a purple, undermined border, commonly affecting the lower extremities and abdomen.
