Erythema nodosum

Erythema nodosum (EN) is an inflammatory condition characterized by painful, red nodules, typically located on the shins. It often indicates an underlying systemic condition or infection. This article provides a comprehensive overview of EN, including its causes, symptoms, diagnosis, and treatment options.

Definition

Erythema nodosum (EN) is a type of panniculitis, which is inflammation of the fat layer under the skin. It presents as tender, red bumps or nodules, usually on the lower legs.

Causes

EN can be triggered by various factors, including:

1. Infections:
   • Bacterial: Streptococcal infections, tuberculosis.
   • Viral: Epstein-Barr virus, hepatitis B and C.
   • Fungal: Coccidioidomycosis, histoplasmosis.
2. Medications:
   • Sulfonamides, oral contraceptives, and certain antibiotics.
3. Systemic Conditions:
   • Autoimmune Diseases: Sarcoidosis, inflammatory bowel disease (Crohn's disease and ulcerative colitis).
4. Pregnancy:
   • Hormonal changes can trigger EN.
5. Idiopathic:
   • In some cases, no specific cause is identified.

Symptoms

Common symptoms of EN include:

1. Tender Nodules:
   • Painful, red or purple lumps, typically on the shins, but can also appear on the thighs, forearms, and other areas.
2. Flu-like Symptoms:
   • Fever, fatigue, and joint pain may accompany the skin lesions.
3. Lesion Changes:
   • Nodules may change color over time, becoming bruise-like as they heal.
4. Symmetrical Distribution:
   • Lesions often appear on both sides of the body symmetrically.

Diagnosis

Diagnosing EN involves:

1. Clinical Examination:
   • Visual and physical examination of the characteristic nodules.
2. Medical History:
   • Reviewing recent infections, medications, and systemic conditions.
3. Laboratory Tests:
   • Blood tests to check for signs of infection or inflammation (elevated ESR or CRP levels).
   • Throat swabs or chest X-rays to identify underlying infections or conditions.
4. Skin Biopsy:
   • In some cases, a biopsy of the nodule may be performed to confirm the diagnosis and rule out other conditions.

Treatment

Treatment of EN focuses on managing symptoms and addressing underlying causes:

1. Rest and Elevation:
   • Resting and elevating the affected limbs to reduce swelling and pain.
2. Medications:
   • NSAIDs: Nonsteroidal anti-inflammatory drugs like ibuprofen to reduce pain and inflammation.
   • Corticosteroids: For severe cases, to reduce inflammation.
3. Treating Underlying Causes:
   • Antibiotics for bacterial infections, antifungal medications for fungal infections, and appropriate treatment for systemic conditions.
4. Compresses:
   • Cool wet compresses to soothe pain and inflammation.

Complications

EN itself is not typically serious, but complications may arise from underlying conditions:

1. Chronic or Recurrent Episodes:
   • EN can recur, particularly if the underlying cause is not addressed.
2. Scarring:
   • Rarely, nodules may leave scars.
3. Persistent Pain and Discomfort:
   • Ongoing symptoms can affect quality of life.

Prevention

Preventive measures for EN include:

1. Managing Infections:
   • Prompt treatment of infections to reduce the risk of developing EN.
2. Medication Review:
   • Monitoring and adjusting medications that may trigger EN.
3. Regular Health Check-ups:
   • Managing chronic conditions and maintaining overall health.

When to See a Doctor

Seek medical attention if experiencing:

• Painful, red nodules on the legs or other parts of the body.
• Accompanying symptoms like fever, joint pain, or fatigue.
• Signs of an underlying infection or systemic condition.

Coping and Support

Living with EN involves:

1. Follow-Up Care:
   • Regular medical check-ups to monitor and manage the condition.
2. Support Groups:
   • Connecting with others who have EN for emotional support.
3. Lifestyle Adjustments:
   • Incorporating rest and stress management techniques into daily life.

Conclusion

Erythema nodosum (EN) is an inflammatory condition that manifests as painful, red nodules on the skin, often triggered by infections, medications, or systemic diseases. Early recognition and treatment of underlying causes are crucial for effective management.

In summary, understanding the causes, symptoms, and treatment options for EN can help individuals manage this condition effectively, ensuring better health outcomes and improved quality of life.