Erythema marginatum
Revision as of 23:10, 10 December 2025 by Rossdonaldson1 (talk | contribs)
Background
- A rare, non-pruritic rash that is one of the major Jones criteria for acute rheumatic fever (ARF)
- Strongly associated with post-streptococcal autoimmune responses, particularly in children and adolescents
- Though uncommon in the ED, its recognition is important because it may be an early or subtle clue to a potentially serious systemic illness, especially when accompanied by joint pain, fever, or cardiac involvement.
Clinical Features
Appearance
- Pink to red, serpiginous or annular macules or patches
- Central clearing, with raised margins
- May coalesce into polycyclic shapes
Distribution
- Typically found on trunk and proximal limbs
- Spares the face
Characteristics
- Transient (lesions may appear and disappear over hours)
- Non-pruritic, often unnoticed by the patient
- Usually occurs early in the course of ARF
Differential Diagnosis
- Urticaria (usually pruritic and shorter-lived lesions)
- Tinea corporis (scaly border; longer duration)
- Erythema multiforme (target lesions; mucosal involvement)
- Erythema migrans (Lyme disease; often has history of tick exposure)
- Erythema annulare centrifugum
- Pityriasis rosea (typically has herald patch, follows cleavage lines)
- Systemic lupus erythematosus (may produce annular lesions)
- Drug eruptions
Evaluation
Workup
- Rapid strep test or throat culture
- Anti-streptolysin O (ASO) or anti-DNase B titers
- CBC (may show leukocytosis)
- ESR/CRP (typically elevated in ARF)
- ECG (look for PR prolongation)
- Echocardiogram if there are signs/symptoms of carditis
Diagnosis
Diagnosis of erythema marginatum is clinical and often supportive in the context of other signs of acute rheumatic fever. Confirm diagnosis of ARF using revised Jones criteria:
- Major criteria: migratory arthritis, carditis, chorea, erythema marginatum, subcutaneous nodules
- Minor criteria: fever, arthralgia, elevated ESR/CRP, prolonged PR interval
- A diagnosis of ARF typically requires 2 major or 1 major + 2 minor criteria, plus evidence of recent group A Streptococcus infection.
Management
- Treat underlying acute rheumatic fever:
- Penicillin or other antibiotics to eradicate streptococcal infection
- Aspirin or NSAIDs for arthritis
- Corticosteroids in severe carditis
- Skin lesions themselves do not require direct treatment, as they are self-limited
- Patient and family education about recurrence prevention and long-term prophylaxis
Disposition
Discharge
- If well-appearing, hemodynamically stable, and has a plan for follow-up with cardiology and primary care for rheumatic fever management
Admit
- There is suspected or confirmed carditis
- Patient is febrile, toxic, or has signs of systemic involvement
- Requires workup and treatment initiation for suspected acute rheumatic fever