Cholinergic urticaria is a skin rash brought on by a hypersensitive reaction to body heat. Symptoms follow any stimulus to sweat such as exercise, heat from the sun, saunas, and hot showers, spicy foods which may cause an increase in body temperature or even stress due to blushing or anger. Some people only have symptoms during the winter months where their body temperature rises.
Causes
The main cause of cholinergic urticaria is a rise in the temperature of the body resulting in sweating. Common factors that may trigger this skin rash include:
- Exercising
- Hot baths/showers
- Fever
- Occlusive dressings
- Eating spicy foods
- Emotional stress
Symptoms
Main symptoms that can be noticed on a person suffering from cholinergic urticaria include:
Itching, burning, tingling, warm sensation preceding the arrival of numerous small weals with surrounding bright red flares.
Rash is often very itchy.
Rash is more prominent on the upper trunk and arms. It does not affect the palms or soles and rarely the armpits.
Sometimes the tiny weals join together to form a large swelling.
Patients who are more severely affected may experience headaches, salivation, palpitations, fainting, shortness of breath, panting, abdominal cramps and diarrhoea.
Treatment
Cholinergic urticaria can be very difficult to treat. Most treatment plans for cholinergic urticaria involve being aware of one's triggers. Often it is handled just with limiting one's exposure to triggers such as strenuous exercise or heat. For some, the reaction can be limited by making sure to wear light breathable clothing allowing the body to remain cool. Also, gradually warming the body with light exercising first can help limit the effects in some people. Since an attack can often be felt coming on, it can sometimes be halted by rapid cooling, such as applying cold water or an ice pack to the skin immediately. Severe cases of cholinergic urticaria have been successfully treated with danazol, which is an anabolic steroid. Use of this medication is limited as it has severe side effects.
