Think you’re allergic to running? You actually could be!
Pounding the muddy fields during school cross country races, PE teachers are sure to have heard the excuse, “I’m allergic to running,” more than once. Now a new study has revealed that it could actually be a real thing, with a genetic mutation meaning that vibration can induce a rare form of hives.
It’s not just running that can trigger the painful skin rash, as a bumpy bus journey, clapping your hands or drying them on a towel could also cause the welts to appear.
It’s a condition known as vibratory urticaria, and it means that sufferers’ cells have an exaggerated response when compared to those who don’t have the mutation.
As well as a rash, vibratory urticaria can lead to symptoms such as headaches, blurry vision, fatigue and a metallic taste in the mouth which usually disappear within an hour. However, those affected could suffer several episodes every day.
A team of scientists at the National Institutes of Health (NIH) used three families as subjects for the study, within which several generations have experienced the condition.
In a healthy person, mast cells in the skin and other tissues of the body release the substance histamine and other inflammatory chemicals into the blood as a response to certain situations and stimuli – known as degranulation.
Researchers believed the mast cells had a vital part in vibratory urticaria, so measured the levels of histamine in the blood during a sufferer’s hive episode.
The results showed that the levels of histamine rose dramatically when the mast cells responded to the vibration, and decreased after around an hour – meaning that these cells had then finished excreting chemicals into the system.
An increase in tryptase, another indicator of mast cell degranulation, was also noted in the skin around the rash area.
“Notably, we also observed a small increase in blood histamine levels and a slight release of tryptase from mast cells in the skin of unaffected individuals exposed to vibration,” the study's author, Dr Hirsch Komarow, of the National Institute of Allergy and Infectious Diseases’ Laboratory of Allergic Diseases, said according to the Daily Mail Online.
“This suggests that a normal response to vibration, which does not cause symptoms in most people, is exaggerated in our patients with this inherited form of vibratory urticaria.”
The condition was first researched by scientists at Yale University back in 1981, when they were approached by a family with symptoms of vibratory urticaria. It was found that the sufferers had a single mutation in the ADGRE2 gene.
Going forward, the NIH scientists are hoping to conduct further research into the disorder and find out other ways the gene is mutated.