What Is Your Diagnosis? Pressure Alopecia

A 28-year-old man underwent an uncomplicated modified Ravitch procedure for elective repair of asymmetric pectus carinatum. The patient was placed under endotracheal anesthesia and remained in the supine position for the 5-hour operation with his head supported by a pad. Temperature and blood pressure levels were within reference range throughout the operation, and his blood loss was 50 mL. Five hours after the operation, he reported scalp swelling and tenderness around the occiput, and his primary care team noted edema localized to a rectangular region measuring 3×8 cm, with the affected area remaining similar in size over the intervening days. Dermatology was consulted on postoperative day 3. A localized 3×8-cm band of indurated and edematous skin with serous exudate and tenderness on palpation was noted on the occipital scalp. Overlying hair remained in place. Local wound care instructions were provided to the patient and his primary care team, and a 2-week outpatient follow-up was scheduled. On follow-up, the edema and induration had fully resolved; however, a well-demarcated patch of alopecia measuring 3×7 cm had developed on the affected scalp. Tufts of telogen hairs could be easily removed from the edges of the alopecic patch. Minoxidil solution 2% applied twice daily to the affected area was recommended, and at 1-month follow-up, fine velluslike hairs were present throughout the affected patch.