Vibratory Urticaria
If you happen to be among the few individuals afflicted by the rare condition known as vibratory urticaria, you might approach tasks like operating lawnmowers or using electric mixers with caution. In this peculiar condition, even mild friction or vibration against the skin, such as when drying off with a towel, can lead to the sudden emergence of hives, facial flushing, headaches, or an unusual metallic taste sensation. Vibratory urticaria is exceedingly rare, with only a handful of documented cases discovered by diligent researchers over the years. However, a recent genetic investigation involving three unique families has unveiled a potential underlying mechanism for these perplexing symptoms.
Published online in The New England Journal of Medicine, the research sheds light on a mutation identified in a gene called ADGRE2. This mutation was found in 22 individuals afflicted with vibratory urticaria but was notably absent in 14 of their unaffected relatives. ADGRE2 encodes a receptor protein located on the surface of mast cells, immune cells found in the skin that release inflammatory molecules, including histamines, responsible for increasing blood flow and potentially causing hives. Interestingly, the researchers observed that the act of shaking these mast cells in a laboratory dish resulted in the separation of two subunits of the receptor protein, triggering histamine release. In those with the newly identified mutation, the receptor proved to be more prone to this separation, leading to an exaggerated immune response at the site of physical irritation, ultimately causing the symptoms associated with vibratory urticaria.