Cholinergic urticaria is a subtype of urticaria and it features with a sudden skin reaction. The condition occurs due to hypersensitivity to body heat. It typically develops after exercise, exposure to the sun, hot showers and saunas or it may develop after consuming spicy food. So all the previously mentioned stimulate the body to sweat and this consequently results in characteristic skin rash. To sum up, all the patients suffering from cholinergic uriticaria develop symptoms of the disease after they are exposed to any kind of stimuli which induce increased production of sweat.
Pathophysiology and Causes of Cholinergic Urticaria
The hypothalamus is the part of the brain in charge of regulation of body temperature. Once it detects increase in the body temperature it signals the sweat glands to produce sweat. This is achieved thanks to a neurotransmitter called acetylcholine. This neurotransmitter assists in degranulation of specific cells in the skin called the mast cells. The mast cells disintegrate and release histamine. Since plenty of mast cells release excessive amount of histamine rapidly this consequently activates inflammatory response of the nearby tissues. The very inflammation is in a form of skin flushing and the skin becomes sticky and prickly. Normally a release of sweat from the sweat glands ceases hypersensitive reaction. But in people suffering from cholinergic urticaria it is hard to release the sweat and this leads to specific symptoms and signs of the disease.
Symptoms of Cholinergic Urticaria
People suffering from cholinergic urticaria start to experience unpleasant sensations the moment temperature of the surrounding starts to increase. The skin becomes extremely itchy and this sensation may affect each and every part of the body. Still, itching sensation most commonly affects the face, scalp and the upper torso. The person may also complain about prickling and tingling sensations. One more characteristic of cholinergic urticaria is flushing or reddening of the skin. Reddening of the skin occurs due to dilatation of the skin blood vessels. In some cases the skin is covered with small, pin point hives. Furthermore, skin changes may be in a form of small weals and raised welts but they only occur if the skin is vigorously scratched. And finally, there is generalized anhidrosis. A lack of sweat production is either partial or total.
Treatment for Cholinergic Urticaria
This type of urticaria is rather challenging to treat. It is essential for a patient to identify potential triggers and to avoid them. Since many people may feel the attack of urticaria coming on they may try rapid cooling and apply cold water or ice pack onto the skin. The doctors most commonly prescribe antihistamines. These medications are effective and may prevent outbreaks of cholinergic urticaria. Corticosteroids are prescribed only in a severe form of the disease.