Erythema Nodosum: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Erythema Nodosum?
A dermatologist, a doctor who treats skin conditions, can diagnose erythema nodosum. A rheumatologist, a doctor who treats joint and immune conditions, may help if the diagnosis is unclear. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is erythema nodosum?
Erythema nodosum is an inflammatory disorder. Inflammation is redness and swelling from the body's defense response. The disorder causes tender, red bumps under the skin. These bumps are called nodules.
Doctors think it is a reaction of the immune system, the body's defense system, to many different triggers. It is uncomfortable but not dangerous in most cases.
Symptoms
The bumps are most common on the front of the shins. They can also appear on the buttocks, calves, ankles, thighs, and arms. At first they are flat, firm, hot, red, and painful lumps. They are about 1 inch across.
Within a few days, the bumps may turn purplish. Over several weeks, they fade to a brownish, flat patch. There is usually no scarring. The pain is often worse when standing. Other symptoms can include:
- Fever.
- A general ill feeling, called malaise.
- Joint aches.
- Swelling of the leg or other affected area.
More than half of people also have joint and muscle pain. The joint pain may last for a few months.
Causes and who gets it
In about half of cases, the exact cause is not known. The rest are linked to an infection or another disorder. Strep throat is the most common infection linked to it. Others include tuberculosis, hepatitis B, and coccidioidomycosis, a fungal infection.
Some medicines can also trigger it. These include penicillin-type antibiotics, sulfonamides, and birth control pills. It may happen during pregnancy. Other linked disorders include sarcoidosis, ulcerative colitis, Behcet disease, leukemia, and lymphoma.
It is more common in women than in men. It is seen most often in women between 25 and 40, but it can happen at any age.
How doctors diagnose it
A provider can usually diagnose erythema nodosum by looking at your skin. In typical cases, no other test is needed to confirm it. Tests may be done to look for the cause. They can include:
- A throat culture to check for a strep infection.
- A chest x-ray to check for sarcoidosis or tuberculosis.
- Blood tests to look for infections or other disorders.
- A punch biopsy of a nodule, which removes a tiny piece of skin to study.
A biopsy is mostly used for unusual cases. One example is nodules that last several weeks.
Treatment
The underlying infection, medicine, or disease should be found and treated. For strep, that means antibiotics. Care for the bumps themselves can include:
- Rest and raising the sore area.
- Hot or cold compresses to ease discomfort.
- Compression to reduce pain when standing.
- Pain medicines and nonsteroidal anti-inflammatory drugs (NSAIDs), which lower swelling and pain.
Stronger options include corticosteroids, which are strong anti-inflammatory medicines, and potassium iodide solution. Your doctor will decide which is right for you.
Symptoms most often go away within about 6 weeks, but they may return. Sometimes the bumps take months to clear, especially if the cause is not treated.
When to see a doctor
Contact your health care provider if you develop red, tender bumps on your shins. Also tell your provider if the bumps last for several weeks, drain fluid, or leave scars. These are not typical and may need a closer look.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. A primary care doctor often sees erythema nodosum first. This kind of doctor can examine the bumps, order tests to look for a cause, and review your medicines. They can also refer you to a skin doctor if the diagnosis is unclear.
Common questions
Is erythema nodosum serious?
Usually not. It is uncomfortable but not dangerous in most cases. It can be linked to another condition, so doctors look for the cause.
How long does erythema nodosum last?
It most often lasts up to about 6 weeks, but it may return. Some bumps take months to clear, especially if the cause is not managed.
What causes erythema nodosum?
In about half of cases, the exact cause is not known. Infections such as strep throat are the most common known trigger. Some medicines and other disorders can also cause it.
Who gets erythema nodosum?
It is more common in women than in men. It is seen most often in women between 25 and 40, but it can happen at any age.
Sources
- NCBI Bookshelf - Erythema Nodosum (StatPearls)
- MedlinePlus - Erythema nodosum
- MedlinePlus - Erythema nodosum on the foot
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
