A 29-year-old man presented with an intensely pruritic rash on his thighs and groin. He had just returned from vacationing in Florida, where itching had begun the previous day while he was swimming at the beach; the rash appeared several hours after he left the water. He denied any systemic symptoms.
Physical examination revealed numerous erythematous, urticarial papules on the thighs and groin, in follicular, perifollicular, and linear arrangements (Figure 1). Biopsy specimens were obtained from 2 separate lesions on the hip (Figure 2). The patient's medical history was significant for childhood eczema and asthma, as well as numerous (approximately 40) jellyfish stings during adolescence.
Bowman PH, Sullivan JR, Hogan DJ, Sanusi ID, Burnett JW. Pruritic Urticarial Papules of the Thighs and Groin. Arch Dermatol. 2000;136(11):1409-1414. doi: