Dr. M.J. Bazos, MD Patient Handout


About Your Diagnosis

Erythema nodosum (EN) is a rash that occurs in a number of different conditions. It almost always occurs on the front of the lower legs (over the shin bones) but can also occur in other places. Erythema nodosum is more common in women than men. Although anyone can get EN, it usually occurs in individuals in their 20s and 30s. Erythema nodosum is caused by inflammation of the fat under the skin. The most common causes of EN are certain medications (in particular, birth control pills and “sulfa” medicines) and infections. Sarcoidosis, ulcerative colitis, Crohn’s disease, thyroid conditions, lupus, and pregnancy can also cause EN. In many individuals the cause of EN is not known. Erythema nodosum is usually diagnosed by the typical way it looks. However, a skin biopsy specimen is sometimes needed to make the diagnosis. A medical history, physical examination, chest X-ray, and certain blood tests may help determine whether there is a specific cause.

Living With Your Diagnosis
Erythema nodosum causes painful, bright-red nodules (or bumps) under the skin. It usually occurs on both legs. Sometimes individuals have fevers, chills, fatigue, and joint pain before the rash begins.

Treatment of the condition causing erythema nodosum usually will help improve the rash. Otherwise, it usually improves on its own in about 6 weeks. If your doctor believes the EN is from a medication, it will be necessary to stop that drug. Nonsteroidal anti-inflammatory drugs (NSAIDs) may help reduce the pain and inflammation of EN. Occasionally, a more potent anti-inflammatory medicine such as prednisone, a cortisone-like medicine, is necessary. Potential side effects of NSAIDs include stomach upset, ulcers, constipation, diarrhea, headaches, dizziness, difficulty hearing, and skin rash. Potential side effects of cortisone-like medicines are increased appetite, weight gain, difficulty sleeping, easy bruising, and stomach upset.

The DOs
• Take your medicines as prescribed.
• Follow your doctor’s treatment instructions.
• Ask your doctor which over-the-counter medications you may take with your prescription medications.

The DON’Ts
• Don't wait to see if side effects from medications will go away.

When to Call Your Doctor
• You experience any medication side effects.
• The treatment is not decreasing your symptoms in a reasonable amount of time.
• You develop new, unexplained symptoms.