“I get hives when I get overheated” was the complaint of a thirty-year-old woman. But the problem was more complex than this. Unraveling her lengthy history we learned that the hives came out not only from being in a hot room, but also whenever she took a hot bath. Furthermore, she suffered from attacks of intense flushing of her skin. All this could be brought on also by emotional stress. Even exercise triggered her problem. She had suffered these attacks for six years without relief, and they were increasing in severity and frequency. In the past year during attacks she had experienced intense itching of her entire skin, along with feelings of weakness, headaches, and palpitations. She had consulted many doctors and taken a wide range of medications without help.

The gravity of her problem demanded hospitalization for complete analysis. With blood studies we were able to rule out the two rare tumors known to produce episodic flushing, carcinoid and pheochromocytoma. A strict elimination diet and avoidance of all medications also did nothing to lessen her attacks. Day by day, as we weathered her attacks with her, we realized her lesions began as hives with tiny red halos, characteristic of so-called “cholinergic hives.” In such cases patients become sensitive to acetylcholine, a chemical released from sympathetic nerve endings in times of stress. This compound also causes blood vessels to dilate, which leaves the skin with a red flush.