Erythema nodosum

Last updated: Tuesday, 30, November, 2010
Causes/AssociationsAppropriate Tests
Review clinical findings.FBC, blood film. Skin biopsy (including subcutaneous fat) if diagnosis uncertain.

Idiopathic

Streptococcus pyogenes infection

Throat swab, wound swab – microscopy and culture (skin lesion); anti-deoxyribonuclease B antibodies, anti-streptolysin O titre. 

Drug reactions, especially;

  • Penicillins
  • Sulphonamides
  • Oral contraceptives
  • Iodide

Sarcoidosis

Crohn's disease

Ulcerative colitis

Lymphoproliferative disorders

Tuberculosis

Leprosy