Target sign

A dermatological or radiologic pattern characterized by concentric rings or a central nodular opacity surrounded by a ring-like opacity, resembling a target or bull’s-eye.

Causes

• Dermatological causes

  • Erythema migrans (Lyme disease)

  • Erythema multiforme

  • Medication reactions

  • Fixed drug eruptions

• Gastrointestinal causes

  • Intussusception

  • Crohn’s disease

  • Bowel infection

  • Bowel ischemia

  • Gastrointestinal cancer

• Malignancy

  • Schwannoma

  • Liver metastasis

• CNS tuberculoma