ERYTHEMA NODOSUM

General Information

DEFINITION--An inflammatory disease of the skin and tissue under the skin, characterized primarily by painful red nodules on the legs. It is not contagious.

BODY PARTS INVOLVED--Skin of the legs, especially areas over the large bone in the lower leg. The disease occasionally involves the arms or other areas.

SEX OR AGE MOST AFFECTED--Both sexes and all ages, but more likely in females (ages 12 to 40).

SIGNS & SYMPTOMS--

Nodules with the following characteristics:

• Nodules are red, painful or tender, and warm.
• Nodules are large (4cm to 10cm). Usually no more than 6 nodules appear at one time.
• Nodules usually occur on the front of the lower legs. They appear on one side and then the other.
• Nodules usually appear suddenly. They are often accompanied by fever and swollen, red, tender ankles and knees.
• Nodules change color from pink to red to blue to brown over 7 to 10 days.

CAUSES--

Sometimes unknown. Known causes include:

• Use of drugs, such as birth-control pills (especially those high in estrogen), sulfonamides, iodides and bromides.
• Preceding infection, including: streptococcus (most common), coccidioidomycosis, histoplasmosis, sarcoidosis, blastomycosis, tuberculosis and Yersinia infections (See Glossary).
• Autoimmune disease.
• Chronic bowel inflammation.
• Dysproteinemia (See Glossary).
• Consumption of foods with food dyes or preservatives.
• Cancer.

RISK INCREASES WITH

• Pregnancy.
• Those listed in causes.

HOW TO PREVENT--Remove or treat the cause, if it can be identified.

What To Expect

DIAGNOSTIC MEASURES--

• Medical history and physical exam by a doctor.
• Laboratory studies, such as antistreptococcal titre or sedimentation rate.
• X-rays of the chest to detect sarcoidosis or tuberculosis.

APPROPRIATE HEALTH CARE

• Doctor's treatment.
• Self-care after diagnosis.

POSSIBLE COMPLICATIONS

• None expected from erythema nodosum.
• Other complications can arise depending on the cause.

PROBABLE OUTCOME--Individual nodules diminish in size and tenderness and heal in 10 to 20 days. However, others may begin. The disease may last several months. Once it disappears, erythema nodosum probably will not return. Treatment hastens recovery.

How To Treat

GENERAL MEASURES--

• Elevate the legs whenever possible.
• Use elastic wrap or support stockings.
• Use wrapped or immersion soaks (see Appendix) to hasten healing and relieve discomfort. Warm-water soaks are usually more soothing for pain or inflammation. Cool-water soaks feel better for itching.

MEDICATION--

• For minor discomfort, you may use non-prescription drugs such as acetaminophen.
• Your doctor may prescribe aspirin, a nonsteroidal anti-inflammatory drug or cortisone drugs to reduce inflammation. (Topical medications usually do not help.)

ACTIVITY--Rest in bed as much as possible with the legs elevated. Overexertion will cause lesions to recur. When symptoms subside, resume normal activity slowly. Allow 3 weeks for recovery.

DIET--No special diet.

Call Your Doctor If

• You have symptoms of erythema nodosum.
• The following occurs during treatment: Symptoms don't improve after 3 days of treatment. Fever.
• Any new symptoms arise that you think may be due to the disorder or the medications prescribed.