Erythema Nodosum

Overview

Erythema nodosum (EN) is an inflammatory condition that causes tender, red bumps (nodules) to form under the skin, typically on the shins. It represents the most common form of panniculitis, which is inflammation of the fat tissue beneath the skin.

Key Characteristics

• Appearance: Round, raised, red or purple tender nodules
• Size: Usually 1-5 cm in diameter
• Location: Most commonly on shins, but can appear on other areas
• Duration: Typically resolves within 2-8 weeks

Common Causes

Primary Triggers:

1. Infections

   • Streptococcal throat infections
   • Tuberculosis
   • Viral infections

2. Medications

   • Birth control pills
   • Antibiotics
   • Sulfa drugs

3. Medical Conditions

   • Inflammatory bowel disease
   • Sarcoidosis
   • Pregnancy

Symptoms

Main Symptoms:

• Tender, warm nodules
• Fatigue
• Low-grade fever
• Joint pain
• Ankle swelling

Diagnosis & Treatment

Diagnosis Methods:

• Physical examination
• Medical history review
• Blood tests
• Chest X-ray
• Throat culture (if infection suspected)

Treatment Options:

1. Supportive Care

   • Rest and leg elevation
   • Cool compresses
   • NSAIDs for pain and inflammation

2. Treatment of Underlying Cause

   • Antibiotics if infection-related
   • Discontinuation of triggering medications
   • Management of associated conditions

Prevention & Self-Care

• Monitor for triggers
• Take prescribed medications as directed
• Rest when nodules are active
• Wear comfortable, loose clothing

When to Seek Medical Care

• New nodules appear
• Severe pain develops
• Fever persists
• Symptoms worsen or don't improve

Prognosis

Most cases resolve within several weeks without permanent scarring. However, recurrence is possible, especially if the underlying cause isn't addressed.