The cause of this condition is poorly understood. Microscopic examination of affected tissue shows ischemic necrosis, and so various hypotheses exist to explain this ischemia, including vasospasm from needle prick, the injected drug, or cold compresses applied to the wound.
Livedoid dermatitis
Essential dermatitis
Molluscum dermatitis
Blister beetle dermatitis
Actinic prurigo
Phototoxic tar dermatitis
Lacquer dermatitis
Alopecia mucinosa