“Why can't I sweat?” was a question of a twenty-three-year-old roofer. He knew he couldn't sweat. He had avoided the heat as a youngster, knowing that headaches, nausea, and shortness of breath always came with hot weather. He became lightheaded and feverish in the hot sun. His parents had told him it was a family trait, with his grandfather and aunt having the same problems.

He had long complained of tender painful fingers and toes, as well as strange red dots around his “belly button.” The pain in his fingers became much worse when he exercised or became overheated. And the red dots were becoming more numerous. Now they were also on his thighs and scrotum.

As a child he had been able to avoid conditions of high temperature. But now, working in the heat was unavoidable. An hour's work triggered a fever of over 100°F. At work he kept a sponge and a 2-gallon jug of water at his side. He had absolutely no sweat for the evaporative cooling we all enjoy. He had never been seen by a dermatologist, but now, after twice collapsing and becoming unconscious at work, he came to see us about his lack of sweating.

The only thing we saw were numerous pinhead-size reddish purple spots, looking like raised tuffs of blood vessels in the periumbilical, pelvic, genital, and thigh areas. The blood vessels of his eyeballs were also enlarged and tortuous.