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    Erythema nodosum

    Erythema nodosum is an inflammatory disorder. It involves tender, red bumps (nodules) under the skin.

    Causes

    In about half of cases, the exact cause of erythema nodosum is unknown. The remaining cases are associated with an infection or other systemic disorder.

    Some of the more common infections associated with the disorder are:

    Erythema nodosum may occur with sensitivity to certain medicines, including:

    • Antibiotics, including amoxicillin and other penicillins
    • Sulfonamides
    • Sulfones
    • Birth control pills
    • Progestin

    Sometimes, erythema nodosum may occur during pregnancy.

    Other disorders linked to this condition include leukemia, lymphoma, sarcoidosis, rheumatic fever, Behcet disease, and ulcerative colitis.

    The condition is more common in women than it is in men.

    Symptoms

    Erythema nodosum is most common on the front of the shins. It may also occur on other areas of the body such as the buttocks, calves, ankles, thighs, and arms.

    The lesions begin as flat, firm, hot, red, painful lumps that are about 1 inch (in) or 2.5 centimeters (cm) across. Within a few days, they may become purplish in color. Over several weeks, the lumps fade to a brownish, flat patch.

    Other symptoms may include:

    • Fever
    • General ill feeling (malaise)
    • Joint aches
    • Skin redness, inflammation, or irritation
    • Swelling of the leg or other affected area

    Exams and Tests

    Your health care provider can diagnose this condition by looking at your skin. Tests that may be done include:

    • Punch biopsy of a nodule
    • Throat culture to check for a strep infection
    • Chest x-ray to check for sarcoidosis or tuberculosis
    • Blood tests to look for infections or other disorders

    Treatment

    The underlying infection, medicine, or disease should be identified and treated.

    Treatment may include:

    • Nonsteroidal anti-inflammatory drugs (NSAIDs).
    • Stronger anti-inflammatory medicines called corticosteroids, taken by mouth or given as a shot.
    • Potassium iodide (SSKI) solution, most often given as drops added to orange juice.
    • Other oral medicines that work on the body's immune system.
    • Pain medicines (analgesics).
    • Rest.
    • Raising the sore area (elevation).
    • Hot or cold compresses to help reduce discomfort.

    Outlook (Prognosis)

    Erythema nodosum is uncomfortable, but not dangerous in most cases.

    Symptoms most often go away within about 6 weeks, but may return.

    When to Contact a Medical Professional

    Contact your provider if you develop symptoms of erythema nodosum.

    Open References

    References

    James WD. Diseases of the subcutaneous fat. In: James WD, ed. Andrews' Diseases of the Skin: Clinical Dermatology. 14th ed. Philadelphia, PA: Elsevier; 2026:chap 18.

    Korsten P, Sweiss NJ, Baughman RP. Sarcoidosis. In: Firestein GS, McInnes IB,  Koretzky GA, Milkuls TR, Neogi T, O'Dell JR, eds. Firestein & Kelley's Textbook of Rheumatology. 12th ed. Philadelphia, PA: Elsevier; 2025:chap 122.

    Kuhn KA, Bewtra M, Mayer A, Ogdie A. Inflammatory bowel disease-associated arthritis and other enteropathic arthropathies. In: Firestein GS, McInnes IB, Koretzky GA, Milkuls TR, Neogi T, O'Dell JR, eds. Firestein & Kelley's Textbook of Rheumatology. 12th ed. Philadelphia, PA: Elsevier; 2025:chap 79.

    Moon M, Guerrero AM, Li X, Koch E, Gehris RP. Dermatology. In: Zitelli BJ, McIntire SC, Nowalk AJ, Garrison J, eds. Zitelli and Davis' Atlas of Pediatric Diagnosis. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 8.

    Shields BE, Forrestel A, Rosenbach M. Erythema nodosum. In: Lebwohl MG, Heymann WR, Coulson IH, Murrell DF, eds. Treatment of Skin Disease: Comprehensive Therapeutic Strategies. 6th ed. Philadelphia, PA: Elsevier; 2022:chap 76.

      • Erythema nodosum associated with sarcoidosis

        Erythema nodosum associated with sarcoidosis - illustration

        This picture shows reddish-purple, hard (indurated), painful nodules (erythema nodosum) that occur most commonly on the shins. These lesions may be anywhere on the body and may be associated with tuberculosis (TB), sarcoidosis, coccidioidomycosis, systemic lupus erythematosis (SLE), fungal infections, or in response to medications.

        Erythema nodosum associated with sarcoidosis

        illustration

      • Erythema nodosum on the foot

        Erythema nodosum on the foot - illustration

        This person has erythema nodosum nodules on the feet. The feet are red and painful. This disorder may be associated with drugs or infections.

        Erythema nodosum on the foot

        illustration

        • Erythema nodosum associated with sarcoidosis

          Erythema nodosum associated with sarcoidosis - illustration

          This picture shows reddish-purple, hard (indurated), painful nodules (erythema nodosum) that occur most commonly on the shins. These lesions may be anywhere on the body and may be associated with tuberculosis (TB), sarcoidosis, coccidioidomycosis, systemic lupus erythematosis (SLE), fungal infections, or in response to medications.

          Erythema nodosum associated with sarcoidosis

          illustration

        • Erythema nodosum on the foot

          Erythema nodosum on the foot - illustration

          This person has erythema nodosum nodules on the feet. The feet are red and painful. This disorder may be associated with drugs or infections.

          Erythema nodosum on the foot

          illustration

        A Closer Look

         

        Tests for Erythema nodosum

         

        Review Date: 8/2/2025

        Reviewed By: Ramin Fathi, MD, FAAD, Director, Phoenix Surgical Dermatology Group, Phoenix, AZ. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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