Pressure Urticaria in an Infant Appearing Similar to Physical Abuse

A healthy Hispanic boy was born via cesarean delivery after an uncomplicated pregnancy. At 4 weeks old , his parents brought him to the emergency department for bruising on both soles of the feet. At 6 weeks old, his parents brought him to primary care for new bruises on his arms and back. After evaluation, primary care referred the patient to the emergency department. The parents denied any recent trauma, fever, cough, decreased urine, or change in appetite. Because of 2 episodes of unexplained bruising, the Department of Children and Families was granted emergency custody of the child. Hematology and ophthalmology did not identify any clear abnormalities. Skeletal surveys were normal. Dermatology was consulted. The examination was normal except for pink blanching patches on the upper back and linearly arranged pink blanching papules on the right lower leg. No crusting, erosions, hyperpigmentation, purpura, petechiae, or ecchymoses were seen. These lesions completely resolved the next day. He tested positive for dermatographism and developed similar lesions on his soles after pushing his feet down onto a soft surface. The intermittent urticarial skin changes were most consistent with physical urticaria. Such lesions could be mistaken for trauma; however, blood vessel damage typically results in progressive coloration changes for >1 day. At the emergency court hearing, given the concurring medical opinions of the dermatologist, pediatrician, and Child Protective Services, the judge returned full custody to the parents. This case reveals the value of dermatologic expertise in assessing skin changes, particularly those associated with physical abuse.