47-Year-Old Man With Pruritus

47-year-old man with a medical history of headaches and seasonal allergies presented to the primary care clinic in late fall for evaluation of diffuse pruritus of 6 weeks’ duration that had occurred after initiating a new diet. The diet mostly restricted foods like dairy, soy, nuts, grains, and processed foods, but he stated that he had substantially increased his consumption of coconut and various spices including turmeric. The itching was present over most of his body but most prominent on the inner thighs and most notable after a hot shower. He provided picturesfromrecent episodes thatillustrated linear excoriations on the thighs. When he showered in cooler water, the diffuse pruritus was still present but minimally improved compared with a hot shower. He had been using the same body soap for years but tried a new soap without relief from the itching. In addition, he changed laundry detergent from one he had used for years with no relief. He had no occupational or habitual exposures that are suspected to contribute to pruritus. Overthe-counter hydrocortisone cream applied to his thighs provided minimal relief. His weight had been stable, and he reported no constitutional symptoms. On physical examination, the patient was a