This is a type of skin disease that usually affects a certain part of the fatty layer on the skin. It results in painful, reddish, tender lumps often situated just below the knees on the frontal surface of the legs.. These nodules or tender lumps of erythema nodosum range in size from 1-5 cms. The nodular swelling is found to be caused by a certain pattern of edema in the fatty layer of skin.
This condition can be self-limited and usually fades away or settles down on its own in 3-6 weeks. In most cases, it may leave a temporary injured look or a chronic groove in the skin where the fatty layer has been damaged.
Erythema nodosum can have many possible outcomes. Usually, affected areas of nodular tenderness are about a coin size and they may be inflamed off and on for a period of weeks after which they resolve all of a sudden, and each one of the little areas of inflammation will shrink down. The affected area will not be raised or inflamed any more. What they leave behind is a bruised appearance. Then, they resolve completely very fast. Other lesions can sometimes pop up elsewhere. This may occur for a few weeks to months and then finally goes away. However, chronic erythema nodosum may last for years too. Keep in mind that chronic erythema nodosumcan can recur irregularly with or without an underlying disease.
Causes of Erythema nodosum
This condition may occur either as an isolated condition or in connection with other similar conditions. There are various conditions that are associated with erythema nodosum. Some of them are medications such as birth control pills, sulfa-related drugs, estrogens. Other conditions that are associated with erythema nodosum include fungal diseases, infectious mononucleosis, strep throat, sarcoidosis, Behcet's disease, cat scratch disease, inflammatory bowel diseases like Crohn's disease and ulcerative colitis and normal pregnancy.
How is erythema nodosum diagnosed?
This condition involves a straightforward, simple diagnosis. It can be done by examining a patient and noting the typical firm area of raised tenderness. This area might be red in colour. Also, areas which have had lesions resolved will be examined. This area might show a bruised-like appearance. An experienced doctor can diagnose erythema nodosum by careful examination of the affected areas and he will not typically require any other investigative tests.
In case the patient has an isolated, odd area and a doctor not sure to make a correct diagnosis based on its appearance a biopsy can be done to confirm the diagnosis. The biopsy of the inner layers of tissue of skin can prove that it is erythema nodosum if it is. These will show the identifiable fatty layers of inflammation.
How is erythema nodosum treated?
This condition is initially managed by identifying and treating any underlying condition present. At the same time, treatment is directed toward the inflamed skin from the erythema nodosum.
Treatments for this disease include cortisone and anti-inflammatory drugs by mouth or injection. A drug named colchicine is found to be helpful in reducing the inflammation. Make sure the treatment is tailored for a specific patient and conditions present. Even though erythema nodosum is a condition which is often painful and annoying, it does not pose a threat to internal organs.