Erythema nodosum (also called EN) is a type of skin inflammation disorder that is characterized by tender red nodules under the skin. EN is usually located in a certain portion of the fatty layer of skin. EN results in reddish, painful, tender lumps most commonly located in the front of the legs below the knees.
Erythema nodosum is most common on the shins but it may also occur on other areas of the body (buttocks, calves, ankles, thighs, and arms). The tender lumps or nodules of erythema nodosum range in size. The nodular swelling is caused by a special pattern of inflammation in the fatty layer of skin. The lesions begin as flat, firm, hot, red, painful lumps approximately an inch across. Within a few days they may become purplish and over several weeks fade to a brownish, flat patch.
EN is more common in women than it is in men. Erythema nodosum is uncomfortable but it is usually not dangerous. Erythema nodosum can be self-limited and resolve on its own in three to six weeks. Upon resolution, it may leave only a temporary bruised appearance or leave a chronic indentation in the skin where the fatty layer has been injured.
There are several scenarios for the outcome of erythema nodosum. Typically, these areas of nodular tenderness range in size from about a dime to a quarter and they may be tender and inflamed off and on for a period of weeks. They usually then resolve spontaneously, each one of the little areas of inflammation shrinking down and then becoming flat rather than raised and inflamed. They leave a bruised appearance. Then, they resolve spontaneously completely. Other lesions can sometimes pop up elsewhere. This may occur for periods of weeks to months and then eventually goes away. However, chronic erythema nodosum that may last for years is another pattern. Chronic erythema nodosum with intermittent recurrences can occur with or without an underlying disease present.
Other symptoms of EN may include fever, general ill feeling (malaise), joint aches, skin redness, inflammation or irritation and swelling of the leg or other affected area.
In about half of the cases, the exact cause of erythema nodosum is unknown. Some cases may be associated with the following infections. Some of the more common ones are streptococcus (most common), cat scratch disease, Chlamydia, Coccidioidomycosis, Hepatitis B, Histoplasmosis, Leptospirosis, Mononucleosis (EBV), Mycobacteria, Mycoplasma, Psittacosis, Syphilis, Tuberculosis,
Tularemia, Yersinia and pregnancy.
Also, another cause could be sensitivity to certain medications like Amoxicillin and other penicillins, Sulfonamides, Sulfones, Oral contraceptives, other antibiotics and Progestin.
Other associated disorders include leukemia, lymphoma, sarcoidosis, rheumatic fever, Bechet's disease, and ulcerative colitis.
The underlying infection, drug or disease should be identified and treated. Nonsteroidal anti-inflammatory medications (NSAIDs) may reduce symptoms. An oral potassium iodide (SSKI) solution may produce prompt resolution of the nodules.
Corticosteroids or salicylate medications may be needed to reduce acute inflammation. Analgesics and limitation of activity may be needed to control varying amounts of pain.
Topical therapy is not generally needed, although hot or cold compresses may reduce discomfort.
The diagnosis is primarily based on the appearance of the skin nodules. Punch biopsy of a nodule may show characteristic changes (septal panniculitis). Throat culture may be done to rule out a strep infection. Chest X-ray may be done to rule out sarcoidosis or tuberculosis.
Call for an appointment with your health care provider if you develop symptoms of erythema nodosum.
Sources:
http://www.medicinenet.com
http://en.wikipedia.org
http://www.webmd.com
MC Ortega is the former publicist for the late Walter Payton, Coca-Cola and Dunkin’ Donuts. Ortega is a senior communications and messaging executive specializing in media relations, social media, program development and crisis communications. Also, Ortega is an avid traveler and international shopper. Ortega resides with her partner, Craig, dog, Fionne and extensive shoe collection. Ortega also enjoys jewelry design/production and flamenco dancing.