What should you know about cause of erythema nodosum?

The condition produces tender, warm red or purple lumps, commonly over the shins. The lumps are not usually a separate infection in the skin; they reflect inflammation in the fatty layer beneath it. Possible triggers include a recent throat or other infection, a medicine reaction, inflammatory bowel disease, sarcoidosis, or pregnancy. Sometimes no cause is identified. A clinician may ask about recent illness, new medicines, joint symptoms, bowel changes, cough, and fever before deciding whether tests are useful.

Arrange a medical assessment if new painful lumps appear, especially when they are accompanied by fever or joint discomfort. Resting the legs, elevating them, and using a cool compress may ease discomfort. Do not stop a prescribed medicine without advice, even if you suspect it is involved. Treatment focuses on the trigger when one is found; a clinician may also recommend symptom relief, and oral corticosteroid treatment is reserved for selected situations after infection has been considered.

Seek prompt care for rapidly worsening pain, marked swelling, high fever, breathing difficulty, or feeling severely unwell. Contact a clinician soon if the nodules keep appearing, do not settle, or occur with persistent diarrhoea, abdominal pain, cough, or unexplained weight change. These features can point to an underlying problem that needs assessment rather than treatment of the skin alone.

Could a recent infection, medicine, or inflammatory condition be triggering these nodules? Do I need an examination or tests? Which pain-relief options fit my health history? What changes should prompt an earlier review?