Hives after cold exposure (cold urticaria)…

From Dermatology Daily of the American Academy of Dermatology:

Bloomberg News (Jan 12, Cortez) reports, “A single gene mutation causes some immune system cells to shut down at body temperature and sends others into overdrive in the cold, creating a mix of ailments that researchers say constitutes a new medical syndrome.”

MedPage Today (Jan 12, Gever) reports a study in the New England Journal of Medicine finding that “an inherited disease known as cold urticaria results from a gain-of-function mutation in an immune system component that explains the condition’s bizarre web of symptoms.” Researchers found that “deletions in the PLCG2 gene lead to gains in the function of phospholipase C-gamma-2 (PLC-gamma-2),” and the resulting “increase in PLC-gamma-2 activity is consistent with the disorder’s symptoms.”

HealthDay (Jan 12) adds, “The researchers have named the immune disorder PLCG2-associated antibody deficiency and immune dysregulation (PLAID).”

Cold urticaria or hives triggered by exposure to cold temperature is likely to be the symptom of a GROUP of diseases. In the study mentioned above, members of the two families studied have other immune system disorders associated with cold urticaria.

Most patients that I have with cold urticaria only have one single problem with no other apparent immune disease. It is an isolated problem with no familial tendency. This more common form of cold urticaria is likely to be a separate medical entity altogether.

Here is the link to the article in New England Journal of Medicine.