Sweat is known to trigger or exacerbate certain kinds of skin irritation, e.g. eczema or cholinergic urticaria (CholU, a type of hives brought on by exercise).
Why do I sweat a lot?
How does sweating help the body?
A sweat allergy can affect people at any age and appears as small red wheals that become visible in response to an elevated body temperature. In many cases, the sweating can trigger intense itching, burning or stinging.
Two types of irritation are possible. One is that the irritation of damaged skin by the contamination or altered pH in sweat may result in itching and lesions. The other possibility is that there’s a hypersensitivity or mild allergy to the actual contents of the sweat.
How can you treat a sweat allegy?
To manage the symptoms, tannic acid has been found to suppress the allergic reaction, as has regularly showering and bathing. Broken or damaged skin often exacerbates the issue, so areas of skin abrasion caused by clothes rubbing, or similar, can make it worse.
A dermatologist can determine whether you have an allergy or not, so I’d recommend getting an appointment to investigate further.