Erythema Nodosum

What is erythema nodosum?

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.

Who does erythema nodosum affect?

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.

How common is erythema nodosum?

Erythema nodosum affects an estimated 1 to 5 out of every 100,000 people.

How does erythema nodosum affect my body?

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.

What are the symptoms of erythema nodosum?

Symptoms of erythema nodosum range in severity for each person and could include:

• Bumps (nodules) on your skin.
• The bumps are warm to the touch and red to purple, similar to a bruise.
• Bumps are tender and painful.
• Bumps fade into a flat, purple to brown patch after several weeks.

Additional symptoms could include:

• Fever.
• Feeling sick (malaise).
• Fatigue.
• Joint pain.

Where do symptoms of erythema nodosum affect my body?

Erythema nodosum usually targets the front of your shins, but it can affect other parts of your body, including your:

• Legs.
• Buttocks.
• Calves.
• Ankles.
• Thighs.

What causes erythema nodosum?

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.

Infections

Several infections can cause erythema nodosum. The most common infections include:

• Streptococcus infections.
• Viral upper respiratory infections.
• Tuberculosis.
• Hepatitis B.
• Coccidioidomycosis.
• Bacterial gastroenteritis.

Underlying conditions

Some cases of erythema nodosum are a symptom of an underlying condition, which could include:

• Ulcerative colitis.
• Crohn’s disease.
• Inflammatory bowel disease.
• Sarcoidosis.
• Rheumatic fever.
• Behçet’s disease.
• Sweet syndrome.
• Pregnancy.
• Leukemia.
• Lymphoma.

Side effects of a medication

Erythema nodosum could be a side effect of a medicine you take. Medicines that can cause this condition include:

• Antibiotics.
• Sulfonamides.
• Penicillin.
• Contraceptive pills.

Is erythema nodosum an autoimmune disorder?

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.

How is erythema nodosum diagnosed?

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:

• Culture tests or blood tests to identify infections.
• Chest X-ray to look for signs of an infection.
• Skin biopsy, where your provider will remove a small sample of tissue from the affected area of your skin to examine it under a microscope.

How is erythema nodosum treated?

Treatment varies for each person diagnosed with erythema nodosum and depends on what caused your symptoms. Treatment could include:

• Managing or treating any underlying conditions or infections.
• Stop taking medicine that caused your symptoms. Don’t stop taking a medication unless your provider tells you it’s safe to do so.
• Taking medicine to reduce symptoms.
• Elevating the affected part of your body, like placing your leg on a pillow when lying down.
• Resting and avoiding strenuous activity.

Erythema nodosum can resolve on its own after a few weeks to months and doesn’t always need treatment.

What medications treat erythema nodosum?

Treatment could involve taking medications to manage your symptoms, including:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) for swelling and pain.
• Anti-inflammatory medicine (corticosteroids) to reduce swelling.
• Potassium iodide solution to reduce inflammation.
• Analgesics for pain.

What foods should I avoid if I have erythema nodosum?

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.

How soon after treatment will I feel better?

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.

How can I prevent erythema nodosum?

You can’t prevent all cases of erythema nodosum, but you can reduce your risk of having a flare of symptoms by:

• Avoiding medicines that cause erythema nodosum.
• Treating or managing any underlying medical conditions.
• Staying away from other people who are sick with a viral or bacterial infection.

What can I expect if I have erythema nodosum?

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.

Is erythema nodosum life-threatening?

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.

When should I see my healthcare provider?

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.

What questions should I ask my doctor?

• What caused my symptoms?
• How often should I take NSAIDs for pain?
• How do I manage the underlying condition that caused my symptoms?
• How do I prevent this condition from returning in the future?

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.