Erythema Nodosum: Symptoms, Causes, Treatment

What are the symptoms of erythema nodosum?

Erythema nodosum (EN) is a type of skin inflammation that is characterized by red, painful nodules or lumps, usually on the shins. The symptoms of erythema nodosum can vary but typically include:

1. Painful Red or Purple Nodules: These nodules are usually located on the shins but can also appear on other parts of the body, such as the thighs, arms, or trunk. They may start as flat, firm, and warm to the touch, then become raised and tender over time.
2. Symmetrical Appearance: The nodules often appear in symmetrical pairs on both legs.
3. Fever: Some people with erythema nodosum may also develop a fever and feel generally unwell.
4. Malaise: A general feeling of being unwell or fatigued.
5. Joint Pain: Some individuals may experience joint pain or swelling, especially in the ankles, knees, wrists, or elbows.
6. Skin Bruising: In some cases, the nodules may progress to a bruise-like appearance as they resolve.

Erythema nodosum can be associated with various underlying conditions or triggers, including infections (such as streptococcal infections or tuberculosis), medications (such as certain antibiotics or oral contraceptives), inflammatory bowel disease (such as Crohn’s disease or ulcerative colitis), sarcoidosis, and some types of cancers.

If you suspect you have erythema nodosum or experience any of these symptoms, it’s important to see a healthcare provider for proper diagnosis and treatment. Treatment often focuses on addressing the underlying cause and relieving symptoms.

What are the causes of erythema nodosum?

Erythema nodosum (EN) can have various causes, but it is often associated with conditions that cause inflammation in the body. Some common causes and triggers of erythema nodosum include:

1. Infections: EN can be triggered by bacterial infections, such as streptococcal throat infections (including strep throat), as well as viral infections like Epstein-Barr virus (EBV), hepatitis B and C viruses, and fungal infections like coccidioidomycosis and histoplasmosis.
2. Inflammatory Conditions: EN can be associated with inflammatory conditions such as inflammatory bowel disease (Crohn’s disease and ulcerative colitis), sarcoidosis, and Behçet’s disease.
3. Medications: Certain medications can trigger EN as a side effect. These may include antibiotics (such as penicillins and sulfonamides), oral contraceptives, nonsteroidal anti-inflammatory drugs (NSAIDs), and some anti-seizure medications.
4. Pregnancy: EN can occur during pregnancy, possibly due to hormonal changes and increased sensitivity to certain triggers.
5. Other Factors: EN has also been linked to other factors such as exposure to certain chemicals, immune system disorders, and some cancers (such as lymphoma and leukemia), although these associations are less common.

In many cases, the exact cause of erythema nodosum may not be identified. It is believed that the condition results from a hypersensitivity reaction in the body, leading to inflammation in the fatty layer of the skin. Identifying and treating any underlying cause or trigger is key to managing erythema nodosum effectively.

How is the diagnosis of erythema nodosum made?

Diagnosing erythema nodosum (EN) typically involves a combination of a physical examination, a review of your medical history, and possibly some tests to rule out other potential causes. Here’s what you can expect:

1. Physical Examination: A healthcare provider will examine the skin to look for the characteristic tender, red, subcutaneous nodules typically found on the shins.
2. Medical History: Your healthcare provider will ask about your symptoms, any recent illnesses, infections, medications you’re taking, and any underlying medical conditions you may have.
3. Skin Biopsy: In some cases, a skin biopsy may be performed. During a biopsy, a small sample of skin tissue is taken and examined under a microscope to rule out other skin conditions and confirm the diagnosis of EN.
4. Blood Tests: Blood tests may be done to check for signs of infection (such as streptococcal infection or tuberculosis), inflammatory markers, and other potential causes of your symptoms.
5. Chest X-ray: A chest X-ray may be recommended to check for signs of sarcoidosis, a condition that can be associated with EN.
6. Throat Swab: If streptococcal infection is suspected, a throat swab may be taken to check for the presence of streptococcal bacteria.
7. Other Tests: Depending on your symptoms and medical history, other tests may be done to rule out other potential causes of your symptoms, such as inflammatory bowel disease or other autoimmune conditions.

It’s important to see a healthcare provider for proper diagnosis and treatment if you suspect you have EN or if you develop symptoms consistent with the condition. Prompt medical attention can help alleviate symptoms, identify any underlying causes, and improve outcomes.

What is the treatment for erythema nodosum?

Treatment for erythema nodosum (EN) typically focuses on managing the underlying cause, relieving symptoms, and preventing complications. Since EN is often a reactive condition, treating the underlying cause is crucial. Here are common treatment approaches:

1. Treating Underlying Infections: If an infection is identified as the cause of EN, such as streptococcal infection or tuberculosis, antibiotics or other appropriate medications will be prescribed to treat the infection.
2. Anti-Inflammatory Medications: Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, may help reduce pain and inflammation associated with EN.
3. Corticosteroids: In more severe cases or when symptoms are not relieved with NSAIDs, corticosteroids may be prescribed to reduce inflammation. These are typically used for a short period due to their potential side effects.
4. Potassium Iodide: This medication is sometimes used to help resolve nodules more quickly, although its effectiveness can vary.
5. Rest and Elevation: Keeping the affected legs elevated when resting can help reduce swelling and discomfort.
6. Compression Stockings: Wearing compression stockings may help reduce swelling and improve circulation in the legs.
7. Pain Management: Pain relievers, such as acetaminophen (paracetamol), can help manage discomfort.
8. Avoiding Triggers: If certain medications or other factors are identified as triggers for EN, avoiding them can help prevent recurrence.
9. Monitoring: Regular monitoring by a healthcare provider may be necessary to ensure that the condition is improving and to watch for any complications.

In most cases, EN resolves on its own within a few weeks to months, especially with treatment of the underlying cause. However, it can recur in some individuals. It’s important to follow your healthcare provider’s recommendations for treatment and follow-up care.