Erythema Nodosum

Erythema nodosum (EN) is an inflammatory condition characterized by the sudden appearance of painful, red nodules, typically on the shins. It is considered a hypersensitivity reaction to a variety of stimuli, including infections, medications, and systemic diseases.

EN most commonly affects young adults, particularly women aged 20-40. The condition can be associated with infections such as streptococcal pharyngitis, tuberculosis, and fungal infections. It is also linked to systemic conditions like sarcoidosis, inflammatory bowel disease, and pregnancy. Certain medications, including oral contraceptives, can also trigger EN.

Symptoms include the development of tender, erythematous nodules that usually measure between 1-5 cm in diameter. These nodules typically appear on the extensor surfaces of the lower legs but can also affect the thighs and forearms. The nodules evolve over several weeks, starting as firm and red, then becoming softer and less red before eventually resolving without ulceration or scarring.

Treatment for erythema nodosum focuses on addressing the underlying cause and providing symptomatic relief. NSAIDs and potassium iodide can be used to reduce inflammation and pain. Bed rest and elevation of the affected limbs are recommended for severe cases. Identifying and treating any underlying infections or discontinuing causative medications are also crucial in managing EN.

References:

• Schwartz, R. A., Nervi, S. J., & Nervi, S. J. (2007). Erythema nodosum: A sign of systemic disease. American Family Physician, 75(5), 695-700.
• Bohn, S., & Buchner, R. (2006). Erythema nodosum: Etiology, diagnosis, and treatment. Journal of the American Academy of Dermatology, 55(6), 1133-1146.
• Mert, A., Kumbasar, H., Ozaras, R., Erten, S., Tasdelen, F., & Bilir, M. (2007). Erythema nodosum: An evaluation of 100 cases. Clinical and Experimental Rheumatology, 25(4), 563-570.