Several factors can trigger erythema nodosum. Common causes include:
Infections: Streptococcal infections are the most common cause. Others include tuberculosis, Yersinia, and mycoplasma. Medications: Drugs such as sulfonamides, oral contraceptives, and certain antibiotics can induce EN. Autoimmune diseases: Conditions like sarcoidosis, inflammatory bowel disease, and Behçet's disease are associated with EN.
