Cholinergic urticaria is a type of urticaria where there is a sudden reaction that occurs due to an increase in the body temperature. Read more on its causes, symptoms and treatment…
Cholinergic urticaria is a sub-type of urticaria or hives, where a skin rash is brought on by a hypersensitive reaction to body heat or secretion of sweat. The symptoms could occur even after taking a hot shower, eating spicy food, after exercising or may even occur due to stress. People who suffer from this condition otherwise do not exhibit any other abnormal symptoms.
Causes and Pathophysiology
When the hypothalamus in the brain detects an increase in the body temperature, it sends down a neuron chain which activates the sweat glands. The neurons then release the neurotransmitter acetylcholine. This chemical, for reasons not known, aids in the degranulation of mast cells in the skin. This rapid degranulation leads to widespread release of histamine in the body near the sweat glands. This release of histamine activates an inflammatory response in tissues nearby creating an urge to itch. This region becomes sticky and prickly.
There is also some flushing seen. What is queer is that once the sweat glands actually release sweat (which is difficult for a person suffering from cholinergic urticaria), the hypersensitive reaction ceases. It is not exactly understood as to what brings about this release of histamine. It has been postulated that hormonal imbalance, vitamin deficiency or long standing allergies may have a role to play in this. A person may also have a genetic susceptibility to this disease. It may also be spurred on by an autoimmune condition.
There are many symptoms that can help recognize this condition.
- First, the person may suffer from an uncomfortable sensation when the room or the body’s temperature starts to increase. This is often an indicator that a hives reaction is imminent.
- The person often feels extreme itching. This is known as pruritis. This can occur anywhere on the body, though it is most common on the face, scalp and the upper torso and at times the legs. It may at times even affect different parts of the body.
- The person may complain of a prickly sensation on the skin. It may also be tingling which may be mild in nature or causes severe irritation. This sensation often occurs simultaneously with the itching or may just precede the urge to itch.
- There is often flushing of skin. This may occur in a localized manner or may be widespread in nature. Flushing is reddening of skin, as blood vessels near the surface of the skin dilate. This flushing is often warmer and redder than usual. There may also be a burning sensation of the skin. If this region is scratched, there may be the appearance of a weal.
- At times, there may even be formation of small pin point hives on the surface of the skin. These pin point hives are normally red in color. These appear as a result of the reaction and fade away after about half an hour.
- The presence of small wheals and raised welts is a common phenomenon. These normally appear when a person vigorously scratches.
- General anhidrosis, that is, decreased or no production of sweat, is a common phenomenon. Many people find it very difficult to sweat and they first experience the hives reaction before sweating.
The main course of treatment to be followed is the use of antihistamines. These prevent outbreaks of urticaria and thus, are, more often than not, the main course of treatment taken when it comes to cholinergic urticaria cure. In very severe cases, steroids can also be prescribed by a certified doctor. Sometimes, it is said that this condition also responds well to beta blockers.
All these medications must be taken strictly on a prescription basis. However, as they say, prevention is better than cure, so avoid situations where you may end up getting an allergic reaction like hives. Try to prevent staying too much in the sun and wear appropriate clothing to keep the body cool. Certain changes in diet and lifestyle may also help to prevent recurrence of attacks.
This condition is not completely treatable, but one can always take precautions to prevent the occurrence of a cholinergic urticaria attack.