Erythema nodosum

Causes/Associations

Appropriate Tests

 

Review clinical findings. Full blood count, 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 Ab, Antistreptolysin O titre.

Drug reactions, especially;

  • Penicillins
  • Sulphonamides
  • Oral contraceptives
  • Iodide

 

Sarcoidosis

Crohn's disease

Ulcerative colitis

Lymphoproliferative disorders

Tuberculosis

Leprosy