Erythema nodosum is an inflammation of subcutaneous fat that presents as tender, erythematous, nodular lesions. It commonly occurs over the shins, but may occur elswhere e.g., forearms and thighs. It is self-limiting, usually resolving within 6 weeks. The lesions heal without scarring.
- Causes
- Infectious: streptococci, tuberculosis, brucellosis
- Systemic disease: sarcoidosis, inflammatory bowel disease, Behcet’s
- Malignancy or lymphoma
- Drugs: penicillins, sulphonamides, combined oral contraceptive pill
- Pregnancy
- Investigations
- Chest X-ray: for sarcoidosis, tuberculosis, lymphoma, and other pulmonary infections
- Throat swab for group A strep
- Complete blood count
- CRP
- Treatment
- No active treatment (it is self-limiting)
- Analgesia and rest (symptomatic relief)
- Treat the underlying cause
