The next time you use the old allergic-to-exercise excuse to get out of the gym you may want to think again. There is an actual condition called Cholinergic urticarial, where people have imflammatory responses to their own sweat, heat, and/or exercise. Also known as "heat hives," the symptoms of this disease can be mild or severe. In the case of Caitlin McComish, a soccer player at the University of Toledo, her "allergy" to her own sweat is life-threatening as she has gone into anaphylactic shock from exercise. Technically this condition is not an allergy, but a immune response and can be triggered from a variety of things including heat, exercise, spicy foods, stress, or even sitting in a Jacuzzi for too long. Individuals can also suffer similar symptoms from the cold. The name of this disease comes from two sources: cholinergic meaning related to acetylcholine, and urticarial is the medical term for hives. This disorder is not well understood, nor is its prevalence or cause known. Some people experience mere inconvenient hives, while others can experience anaphylaxis. Doctors and researchers are of course, aware of the basic physiological mechanism (Hypothalamus–>Acetylcholine–>Mast Cells–>Histamine Release–>Hives) underlying this condition, but they cannot explain the extreme variability of triggers and symptoms. Further research must be done to fully understand how a seemingly minor inflammatory response can turn into the symptoms that Caitlin McComish has experienced.
Sources:
http://abcnews.go.com/Health/ohio-soccer-player-dangerously-allergic-sweat/story?id=23367577
http://www.cholinergicurticaria.net/
Unfortunately for Caitlin and others with this condition, there is no cure and often times treatments are limited. Although life threatening events may occur (anaphylactic shock), this is rare. Current treatments target symptoms associated with the inflammatory response, where antihistamines and corticosteroids are primarily used. However, prevention seems to be the best form of treatment, such as avoiding triggers that may cause symptoms to develop (spicy foods, stressors, etc).
ReplyDeleteSource: http://www.cholinergicurticaria.net
I wonder if this causes people to stop exercising, and if it does, it makes me wonder if they continue to stay healthy since there really isn't a cure and treatments are so limited. This makes me wonder if the exercise pills we read about for TBL would be effective in keeping these people healthy if they are allergic to exercise. For most people, including me, if I was allergic to something, I try to stay away from it. Although this isn't the case for the Ohio soccer player, most other people may try to stay away from exercising, so this may be a good time to use those exercise pills which mimic the effects of exercise without sweating, ultimately keeping them healthy.
DeleteSource: http://www.cell.com/trends/pharmacological-sciences/abstract/S0165-6147(15)00187-X?_returnURL=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS016561471500187X%3Fshowall%3Dtrue
It appears that the cutaneous inflammation – or wheals – and pain that results from cholinergic uticaria – is a direct result of inhibited expression of AchE (acetylcholinesterase) and decreased levels of CHRM3, the cholinergic receptor muscarinic 3. The exact biochemical mechanism behind the downregulation of both AchE and CHRM3 has been speculated upon, but must be further researched before a lasting cure can be developed. Steroid pulse therapy has been shown to be an effective treatment in some cases, but cold water and wet towels are also an effective non-pharmacological approach. Cholinergic Uticaria truly is a debilitating condition that affects a larger portion of the population than one might expect so it is up to us to delve deeper into the mechanism behind the development of CU to improve the lives of people like Caitlin.
ReplyDeleteSource: http://www.cholinergicurticaria.net; https://en.wikipedia.org/wiki/Cholinergic_urticaria
There have been studies showing the use of anti-immunoglobin E antibodies to treat CU. Immunoglobin E (IgE) typically binds receptors on mast cells to activate the anaphylactic pathway you elucidate in your post, thus anti-IgE ab's can bind free IgE and prevent it from activating mast cells via FcɛRI receptors. Furthermore, by depleting the amount of free IgE in serum, the expression of FcɛRI receptors is downregulated. It was observed in a patient with severe CU that injection with an anti-IgE antibody, omalizumab, the patient reported a complete reversal of symptoms and the ability to engage in rigorous exercise.
ReplyDeleteMetz, M., Bergmann, P., Zuberbier, T., & Maurer, M. (2008). Successful treatment of cholinergic urticaria with anti‐immunoglobulin E therapy. Allergy, 63(2), 247-249.