Erythema Nodosum Lesions: What to Know

These lesions sit beneath the surface of the skin, so they feel firm and sore rather than like a superficial spot. They are often red or warm at first and may later become purple, brown, or bruise-like as they resolve. They usually do not have a central opening, scale, or pus. Several lesions can appear at once, and nearby joints may ache. Similar-looking lumps can have other causes, so photographs, timing, and an examination can help establish what is happening.

Avoid squeezing, needling, or rubbing a lesion because it is not a pimple and surface trauma can add irritation. Rest when the legs are sore, elevate them when comfortable, and use a cool compress with a barrier between the cold source and skin. Wear soft, non-tight clothing and note new lesions, colour changes, fever, joint pain, or recent illness. A clinician may look for a trigger and tailor pain relief. Oral corticosteroid treatment may be discussed only when clinically appropriate after other causes and active infection have been considered.

Arrange prompt assessment if lesions multiply quickly, become much more painful, drain fluid, form an ulcer, or occur with fever or marked illness. Seek urgent help for breathing difficulty, chest pain, fainting, or sudden one-sided leg swelling. An open or draining lesion is not the usual pattern and should be checked.

Do these lesions have the typical features of erythema nodosum? Is a test or biopsy needed to rule out another cause? What symptoms should I record while they change? Which treatment is suitable if pain affects walking?