Dermatologic lesions in Behçet's disease are regarded as important manifestation for diagnosis. Various kinds of cutaneous lesions appear in patients with Behçet's disease. They present as erythema nodosum-like lesion, papulopustular eruption, erythema multiforme-like lesion, thrombophlebitis, skin ulcer, Sweet's syndrome-like lesion, bullous necrotizing vasculitis, and pyoderma gangrenosum. The hyperreactivity of the skin to any intracutaneous injection or needle prick, which is known as pathergy, is one clinically-unique feature of the disease.