Erythema nodosum

Background

Normal dermal anatomy.

• Often marker for systemic disease
• Most common in women 30-50 years of age
  • 1:6 male to female
• Usually a self-limited disease, resolving in 3-6 wks

Associated Disease Processes

• Most often idiopathic
• Drug induced (OCPs, sulfonamides, PCN)
• Tuberculosis
• Fungal disease (Coccidioidomycosis, Histoplasmosis)
• Sarcoidosis
• Ulcerative colitis
• Crohn's disease
• Behcet's disease
• Cat scratch disease
• Mononucleosis
• Streptococcal pharyngitis (most common identifiable cause)
• Normal pregnancy
• Malignancy (leukemia, lymphoma)

Clinical Features

Erythema nodosum in a person who had recently had streptococcal pharyngitis

A single lesion of erythema nodosum.

• Painful
• Non-ulcerative nodules
• Violaceous, erythematous
• Usually anterior tibia, arms, trunk

Differential Diagnosis

• Erysipelas
• Erythema induratum (nodular vasculitis)
• Familial Mediterranean Fever
• Insect bites
• Superficial thrombophlebitis
• Thrombophlebitis
• Urticaria

Evaluation

Erythema nodosum. (A) Symmetric, smooth and shiny, erythematous nodules affecting the both shins of the parient. (B) Classical appearance of septal inflammation.

• Clinical diagnosis

Management

• Treat underlying cause
• NSAIDs
• Potassium Iodide
• RICE, cool wet compresses

Disposition

• Typically outpatient

References

• Hebel et al. Erythema Nodosum. Apr 13, 2015. http://emedicine.medscape.com/article/1081633-overview