An Allergy to Your Own Sweat
People with cholinergic urticaria are essentially having an allergic reaction or hypersensitivity to their own sweat or body heat after a rise in temperature. The condition manifests as an outbreak of hives -- small, itchy, red bumps that may also feel like they're burning or stinging -- that can appear anywhere on the body. That bump in temperature is caused by the usual suspects, such as strenuous activity and eating spicy foods. The rash can last for hours after the initial rise in temperature or outbreak of sweat, and it's very uncomfortable and painful. Those who have the disorder often feel the rash coming on before it happens, and can sometimes stop it by taking a cool shower or applying cold packs to the areas most commonly affected.
The cause of cholinergic urticaria is unknown. It can be aggravated by other conditions and may also be hereditary. The disorder rarely travels alone, either. Instead, it brings along its buddies -- other types of rashes, eczema or allergies. It isn't consistent company, often coming and going over the course of a person's life.
Tips for those with cholinergic urticaria: Try to avoid extreme temperature changes and excessive heat, stay cool in hot weather, and be cautious during strenuous exercise. Some have found relief through antihistamines, steroids and alternative therapies like acupuncture.