A condition that causes painful red nodules to form in the legs, and other places.
Erythema nodosum is an inflammatory disorder. It involves tender, red bumps (nodules) under the skin.
In about half of cases, the exact cause of erythema nodosum is unknown.
- Streptococcus (most common)
- Cat scratch disease
- Hepatitis B
- Mononucleosis (EBV)
Medication associated EN
Erythema nodosum may occur with sensitivity medications, including:
Antibiotics, including amoxicillin and other penicillins
- Birth control pills
Erythema nodosum is most common on the front of the shins, but also can occur in buttocks, calves, ankles, thighs, and arms.
The lesions begin as flat, firm, hot, red, painful lumps that are about 1 inch (2.5 centimeters) across. Within a few days, they may become purplish in color. Over several weeks, the lumps fade to a brownish, flat patch.
- General ill feeling (malaise)
- Joint aches
- Skin redness, inflammation, or irritation
- Swelling of the leg or other affected area
- Punch biopsy of a nodule
- Throat culture to rule out a strep infection
- Chest x-ray to rule out sarcoidosis or tuberculosis
- Blood tests to look for infections or other disorders
Treatment may include:
- Nonsteroidal anti-inflammatory drugs (NSAIDs).
- 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).
- Raising the sore area (elevation).
- Hot or cold compresses to help reduce discomfort.
Erythema nodosum leprae
Erythema nodosum leprosum usually manifests with fever and painful erythematous nodules, but peripheral neuritis, orchitis, lymphadenitis, iridocyclitis, nephritis, periostitis and arthralgias may also occur. Mild episodes may require no therapy, or symptomatic measures such as aspirin administration may suffice. Several drugs are useful for the management of severe episodes.
- Corticosteroids are effective in all patients and should always be used if an acute neuritis is present to prevent permanent nerve injury.
- Thalidomide (Thalomid) is extremely effective in treatment of ENL.
- Clofazimine is also effective for the control of ENL.
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