A 22-year-old United States Army reservist presents to her acute care clinic with a rash of her back, chest and upper extremities. The patient recently completed her APFT (biannual exercise test), and states that the rash occurs frequently after exercising. The rash is itchy and developed during the 2-mile run about 30 minutes earlier. The patient denies nausea, shortness of breath, difficulty breathing, or choking sensation. She has not used any new soaps, lotions, or laundry detergent. Multiple, well-defined, edematous, and erythematous wheals on her back, torso, and extremities are observed upon examination.
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Cholinergic urticaria (hives) is a type of urticaria that is caused by sweating and elevated temperature (heat) produced during exercise.1 Urticaria, which typically resolves within hours, is clinically characterized by swollen, red, well-defined plaques that vary in size.1
In cases of cholinergic urticaria, hives that are approximately the size of a ballpoint pen tip present rapidly and sometimes join to form a large, swollen mass.2 The rash typically appears within a few minutes of perspiring and persists until the body returns to a normal temperature, usually 30 minutes to an hour after exercise.2 In some cases, a burning, tingling, and/or warm sensation precedes the pruritic rash; some people may experience headaches, salivation, palpitations, fainting, shortness of breath, and diarrhea.2
A clinical diagnosis of cholinergic urticaria is made based on patient history and physical examination findings.3 Cholinergic urticaria typically presents as raised lesions that develop following an increase in temperature of the skin during physical activity. Lesions are usually found on the neck and upper thorax but can spread to the entire body.3
Exercise-induced chronic urticaria affects up to 20% of young adults.4 The condition can persist for several years, and, in severe cases, can interfere with daily function.5
The underlying pathophysiologic mechanism is not fully understood. Onset is usually in older children entering adolescence, and the diagnosis is more common among females than males.6 Although cholinergic urticaria is not an allergic reaction and does not produce immunoglobulin E antibodies (the allergic antibody created to respond to a particular substance), the mechanism of action is similar to that of an allergy.
Currently, there is no cure for cholinergic urticaria; instead, the goal of treatment is to relieve symptoms. It is not possible to completely eliminate the rash, so patients with cholinergic urticaria may have to limit strenuous activity. Pretreatment before exercise with an antihistamine (cetirizine or hydroxyzine) may help. If the itchy wheal and flare-type skin reactions occur, the current guideline recommends to use H1-antihistamines as first-line therapy and up to 4 times the approved dose as second-line treatment.5
The patient’s treatment plan consisted of 25 mg of intravenous hydroxyzine with saline and a referral to dermatology. At discharge, the patient was placed on a trial of daily oral cetirizine at 10 mg. Her plan included a return to the acute care clinic in 3 months for evaluation of daily prophylaxis and evaluation for possible discharge from military service if the patient was unable to control her condition because of the rigorous military exercise requirements.
The patient did not show to her scheduled 3 month follow-up appointment and, after 2 missed appointments, the patient was lost to follow up.
Marguerite Lawrence, LTC (Retired) USA, DNP, FNP-BC, PHCNS-BC, is an Assistant Professor of Nursing at Columbus State University. She served over 20 years as a US Army Family Nurse Practitioner. She served at various military duty stations including the Middle East.
1. Emer J, Sivek R, Marciniak B. Sports dermatology: part 1 of 2 traumatic or mechanical injuries, inflammatory conditions, and exacerbations of pre-existing conditions. J Clin Aesthet Dermatol. 2015;8(4):31-43.
2. Seto C. Hives when I work out: am I allergic to exercise? AllergicLiving. Published July 2, 2010. Accessed October 27, 2020. https://www.allergicliving.com/2010/07/02/hives-heat-sweat-allergy/.
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6. Del Giacco SR, Carlsen KH, Du Toit G. Allergy and sports in children. Pediatr Allergy Immunol. 2012;23(1):11-20.