A Chief Complaint of Blisters in an Adolescent.

1. Ankita Deosthali, MD* 2. Laura K. Grubb, MD, MPH* 1. *Tuft’s Children’s Hospital at Tufts Medical Center, Boston, MA A 19-year-old male with no significant medical history presents to the adolescent clinic with the complaint of blisters. He noticed painful blisters a week ago, starting on the middle finger of his right hand and buttocks bilaterally, and then 2 days later another blister emerged on the shaft of his penis. He describes the blisters as clear fluid collections that erupted and then scabbed over. He has been applying an over-the-counter antibiotic ointment, which has not helped. He has also been applying a thick lotion, which made the skin overlying the blisters smoother but did not make them go away. This morning he noticed a small circular lesion in his pubic area, above his penis. He has had no fevers, sore throat, dysuria, hematuria, or penile discharge. The only medication he takes is emtricitabine/tenofovir disoproxil fumarate (Truvada®; Gilead, Foster City, CA) for preexposure prophylaxis against human immunodeficiency virus (HIV). He is sexually active with only male partners, participating in oral (receiver and giver) and anal (receiver) intercourse. He has inconsistent condom use with both oral and anal intercourse. On examination his vital signs are normal, and he appears generally well and in no acute distress. Skin examination reveals ulcers on the middle finger of his right hand, the lower buttocks bilaterally, and the shaft of his penis. The ulcers on his hand and penis are approximately 1.5 cm in diameter, and on his buttocks they are larger, approximately 5 cm in diameter. The ulcers are irregularly shaped red halos without a central clearing with ragged edges and are tender to palpation. In addition, there is a 1-cm tender red papule on his mons pubis. There is no inguinal lymphadenopathy or oral lesions. ### Differential Diagnosis The global incidence of genital …