livedoid dermatitis

Perinatal gangrene of the buttock is a skin condition similar to livedoid dermatitis, and is usually a complication of umbilical artery catheterization, exchange transfusion, or cord injections by means of a syringe.

Livedoid dermatitis (also known as "Embolia cutis medicamentosa," and "Nicolau syndrome") occurs immediately after an intramuscular injection, and is characterized by intense pain and blanching of the overlying skin, known as ischemic pallor.