Nicolau syndrome after intramuscular benzathine penicillin injection.

A 3-year-old boy was admitted to the emergency department with right lower limb pain, edema, and livedoid discoloration that occurred immediately after intramuscular injection of benzathine penicillin. The patient was diagnosed with Nicolau syndrome, a rare complication of intramuscular injection presumed to be related to the inadvertent intravascular injection. It was first reported following intramuscular injection of bismuth salt, but it can occur as a complication of various other drugs. Fasciotomy was carried out due to the resultant compartment syndrome and medical therapy with heparin, corticosteroid, and pentoxifyllin was initiated.