Nicolau syndrome and perforator vessels: a new viewpoint for an old problem.

Nicolau syndrome is rare cutaneous adverse reaction following injection of various drugs. The disease has been associated with almost all classes of medications, such as nonsteroidal anti-inflammatory drugs, local anesthetics, corticosteroids, antibiotics, vitamin B complexes, antihistamines, and vaccines. The most severe cases of this complication occur after injection of nonsteroidal anti-inflammatory drugs. Subcutaneous injection is an important factor in the pathogenesis of the syndrome. We report a case of Nicolau syndrome resulting from intramuscular injection of diclofenac and discuss some precautions to prevent this complication.