Erythema nodosum is an inflammatory disorder that is characterized by tender, red nodules under the skin.

In about half of 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
• Pregnancy
• Sensitivity to certain medications, including:
  • Amoxicillin and other penicillins
  • Sulfonamides
  • Sulfones
  • Oral contraceptives
  • Other antibiotics
  • Progestin

Other associated disorders include leukemia, lymphoma, sarcoidosis, rheumatic fever, Bechet's disease, and ulcerative colitis.

The condition is more common in women than it is in men.

Images

Erythema nodosum associated with sarcoidosis

Erythema nodosum on the foot

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Erythema nodosum Symptoms

Review Date: 10/12/2009
Reviewed By: Kevin Berman, MD, PhD, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)