Cholinergic urticaria is a type of physical urticaria that occurs when the patient is sweating or their body temperature rises above normal. It is characterized by the appearance of a generalized itchy rash with hives (vasodilation lesions and edema of the dermis) 1 to 3 millimeters in length.
Hives can appear anywhere on the skin and the size and itchiness caused will vary depending on the causative etiological agent and the patient himself. If you want to know everything about cholinergic urticaria, read on.
Causes of cholinergic urticaria
Urticaria, in general, can be defined as a skin disease with the appearance of edematous skin lesions, accompanied by itching. These lesions (known as hives ) last between 2 and 6 hours after they appear, but they can reappear in different parts of the body.
Although the pathogenetic mechanism of cholinergic urticaria is not fully understood, there are certain theories. As the Subiza Clinic indicates, one of them is that there seems to be a series of intrinsic disorders in patients that allow the cellular release of histamine when stimulated by cholinergic fibers.
These nerve fibers influence the stimulation of the sweat glands. On the other hand, histamine is an amine that causes many of the well-known allergy symptoms. So it makes sense that cholinergic urticaria and exercise are related.
In summary, we can define the causes of this type of urticaria in 4 large blocks:
- Hypersensitivity to sweat: it is an excessive reaction to the production of sweating.
- Hypohidrosis: pathological lack of sweat production.
- Idiopathic – The underlying cause is unknown.
- Drugs: such as opiates or cholinesterase inhibitors.
According to the International Dermatological Clinic portal, approximately 20% of the world population will present some type of urticaria at any time in their life. On the other hand, the cholinergic variant is very rare.