Exercise urticaria

Exercise urticaria, sometimes mistaken as exercise allergy, itchy legs, itchy legs syndrome or itchy pants syndrome, is a form of urticaria that happens during exercise. It is characterized by itching, swelling or hives on the legs, arms, torso or neck during or after exercise.

Cholinergic urticaria is brought on by a physical stimulus. Although the physical stimulus might be considered to be sweat, the actual precipitating cause is increased body temperature. Lesions usually appear within a few minutes of sweating, and may last for 30 minutes to over an hour.

In extreme cases, the condition can progress to an anaphylactic reaction, causing the person to pass out or suffocate due to blocked airways. People suffering from cholinergic urticaria may carry an epinephrine autoinjector (such as an EpiPen) in case of anaphylaxis.

Cholinergic urticaria (itching)
Seems to be caused by a rise in body temperature, also experienced in saunas, hot tubs, and on hot days. Treated by:
 * Antihistamines
 * Exercising in a cooler environment
 * Reduced workout intensity
 * Stopping exercising at sign of flushing, itchy skin or hives.

Exercise-induced anaphylaxis
A life-threatening drop in blood pressure that can be fatal in major allergic reactions. Seen commonly when a person allergic to certain foods or medications exercises immediately after ingesting them. Symptoms are: Treatments include:
 * Fatigue
 * Unusual warmth
 * Itching
 * Inflammation of the skin progressing to large hives
 * Collapse and unconsciousness
 * Swelling of the throat, difficulty breathing or choking
 * Nausea
 * Vomiting
 * A self-injectable epinephrine kit prescribed by a doctor
 * Avoiding the triggering food or medication at least a day before vigorous exercise.
 * Medical alert jewelry or ID tags describing the condition and sensitive substances.
 * Accompaniment by someone informed of condition able to contact emergency service, like with an emergency telephone number.

Itchy Pants Syndrome
Some people are sensitive to the fabric in various pants, causing itchiness, stinging, and irritation, mainly in the thighs. Not common with cotton, some surmise it is caused by formaldehyde or fabric finishes in the cloth. Sometimes solved by:
 * Wearing cotton-only non-designer blue pre-washed jeans.
 * Wearing skirts.
 * Over-the-counter topical anti-itch medications.