Erythema nodosum causes red to purple, painful bumps to form on your skin. These bumps can form anywhere on your body, but most often affect the front of your shins. An infection, underlying condition or medication can cause erythema nodosum as a symptom. The bumps can resolve on their own within weeks to months.
Erythema nodosum is a condition in which the fat within your skin becomes inflamed. It’s characterized by bumps (nodules) on your shins. This can be a reactive process to an underlying cause.
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Studies show that the condition can affect anyone at any age, but it most often affects women and people assigned female at birth between the ages of 20 and 30. You’re more at risk of getting erythema nodosum if you have an infection, have inflammatory bowel disease or are on certain medications.
Erythema nodosum affects an estimated 1 to 5 out of every 100,000 people.
Erythema nodosum causes bumps to form on your skin. These bumps can be tender, painful and warm to the touch, which can make the affected area of your skin feel uncomfortable. You might notice your skin change color from a red to a purple or brown as your skin heals before it returns to your natural skin tone.
Symptoms of erythema nodosum range in severity for each person and could include:
Additional symptoms could include:
Erythema nodosum usually targets the front of your shins, but it can affect other parts of your body, including your:
The exact cause of erythema nodosum is unknown, but many cases occur in reaction to an infection, an underlying condition or a medication. Some cases of erythema nodosum are idiopathic, which means an underlying cause is never identified.
Several infections can cause erythema nodosum. The most common infections include:
Some cases of erythema nodosum are a symptom of an underlying condition, which could include:
Erythema nodosum could be a side effect of a medicine you take. Medicines that can cause this condition include:
Erythema nodosum isn’t an autoimmune condition. A healthcare provider classifies an autoimmune condition if your body’s immune system attacks normal parts of your body (for example, forming antibodies to attack proteins inside your cells). This isn’t the case in erythema nodosum.
A healthcare provider will diagnose erythema nodosum after a physical exam to learn more about your symptoms, along with learning more about your complete medical history. To confirm your diagnosis, they’ll offer tests that could include:
Treatment varies for each person diagnosed with erythema nodosum and depends on what caused your symptoms. Treatment could include:
Erythema nodosum can resolve on its own after a few weeks to months and doesn’t always need treatment.
Treatment could involve taking medications to manage your symptoms, including:
Studies are ongoing to learn more about how certain foods in your diet can help or reduce symptoms. Eating a healthy, well-balanced diet is usually recommended.
After treatment begins, you could see your symptoms of pain and swelling reduce. The bumps (nodules) and visible signs of the condition will still be on your skin for several weeks to months. During this time, your skin might change color, from red and purple to brown, before returning to your natural skin color. This is normal.
Once your skin heals, it’s possible that symptoms could return in the future.
You can’t prevent all cases of erythema nodosum, but you can reduce your risk of having a flare of symptoms by:
Erythema nodosum can return throughout your life after it goes away. If you manage or treat the underlying condition that caused your symptoms or you stop taking medicine that caused your symptoms, you reduce your risk of having an erythema nodosum flare.
At home, you can take over-the-counter NSAIDs for pain as directed by your healthcare provider. Elevating the affected area of your body helps minimize swelling. For example, if you experience symptoms on your shin, you can put your leg on a pillow when lying down.
If your symptoms are severe and prevent you from going about your day normally, talk to your healthcare provider.
Erythema nodosum isn’t a life-threatening condition. The bumps on your skin, along with the symptoms associated with the condition, typically go away in weeks to months. If your diagnosis of erythema nodosum is the result of an underlying condition, the underlying cause could be life-threatening, but the bumps on your skin are only a temporary symptom.
Visit a healthcare provider if you experience symptoms of erythema nodosum, especially when visible symptoms on your skin combine with a fever or you feel ill (malaise). Your healthcare provider will diagnose your condition and locate the cause of your symptoms to offer treatment so you can feel better sooner.
A note from Cleveland Clinic
Symptoms of erythema nodosum can be painful and bothersome. They can last weeks to months. During this time, you can reduce your symptoms by getting a lot of rest and elevating the affected part of your body. Don’t ignore your symptoms because some cases of erythema nodosum can be a sign of an underlying condition that needs treatment. Contact your provider if your symptoms are severe.
Last reviewed by a Cleveland Clinic medical professional on 12/30/2022.
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Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy