What is erythema nodosum?
Erythema nodosum is characterized by tender, red bumps, usually found symmetrically on the shins.
Up to 55 percent of cases have no clear identifiable cause. Sometimes, erythema nodosum is not a separate disease. Rather, it is a sign of some other infection, disease, or of a sensitivity to a drug.
Diseases that can cause erythema nodosum
These diseases include:
Sarcoidosis (inflammation of the lymph nodes and other organs)
Coccidioidomycosis (infection of the upper respiratory tract and lungs)
Histoplasmosis (an infectious pulmonary disease)
Psittacosis (a flu-like disease)
Ulcerative colitis or Crohn's disease
Medicines that can cause erythema nodosum
These medicines include:
What are the symptoms of erythema nodosum?
The following are the most common symptoms of erythema nodosum. However, each individual may experience symptoms differently. Symptoms may include:
Young adults are particularly susceptible to erythema nodosum. The symptoms of erythema nodosum may resemble other skin conditions. Always talk with your healthcare provider for a diagnosis.
How is erythema nodosum diagnosed?
A biopsy (removal of tissue for exam under a microscope) of a bump can usually confirm the diagnosis. The biopsy is done along with complete lab work. However, the exact cause cannot always be identified. Erythema nodosum caused by medicine can usually be diagnosed by elimination of the medicine causing the reaction. A throat swab may be done to check for strep infection.
Treatment for erythema nodosum
Specific treatment for erythema nodosum will be discussed with you by your healthcare provider based on:
Your age, overall health, and medical history
Extent of the condition
Your tolerance for specific medicines, procedures, or therapies
Expectations for the course of the condition
Your opinion or preference
Treatment may include:
Antibiotics to treat an underlying bacterial infection
Treatment of other underlying cause
Bed rest (to relieve pain)
Nonsteroidal anti-inflammatory medicines
Although erythema nodosum is uncomfortable, it is usually not a serious condition. Symptoms are usually gone within 6 weeks. However, they may appear again.