Cholinergic urticaria

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Cholinergic urticaria
Synonyms	Heat bumps, heat hives
Pronounce	N/A
Specialty	N/A
Symptoms	Itching, redness, small hives
Complications	N/A
Onset	Adolescence or early adulthood
Duration	Chronic
Types	N/A
Causes	Heat, exercise, stress, hot showers
Risks	Atopic dermatitis, asthma, allergic rhinitis
Diagnosis	Clinical diagnosis, provocation test
Differential diagnosis	Urticaria, exercise-induced anaphylaxis, mastocytosis
Prevention	N/A
Treatment	Antihistamines, cooling measures, avoidance of triggers
Medication	N/A
Prognosis	N/A
Frequency	Common in young adults
Deaths	N/A

Cholinergic Urticaria

Cholinergic Urticaria rash

Introduction

Cholinergic Urticaria (CU) is a type of hives associated with increased core body temperature and sweating. It is a physical urticaria triggered by activities that raise body temperature, such as exercise, hot showers, or emotional stress.

Pathophysiology

CU is believed to result from hypersensitivity to acetylcholine, a neurotransmitter involved in stimulating sweat glands. This hypersensitivity leads to histamine release from mast cells, causing the characteristic hives and itching.

Clinical Features

CU presents as small, itchy wheals surrounded by large areas of redness. These typically appear on the trunk and arms and are often associated with sweating or overheating. Patients may also experience accompanying symptoms like headache, salivation, palpitations, or gastrointestinal discomfort.

Diagnosis

Diagnosis of CU is primarily clinical, based on history and presentation. Dermatological tests, such as the exercise challenge or the hot water immersion test, can be used to provoke symptoms under controlled conditions.

Management and Treatment

Treatment of CU involves both symptomatic relief and avoidance of triggers. Antihistamines, particularly H1-receptor antagonists, are the mainstay of pharmacological treatment. Lifestyle modifications, such as avoiding triggers and maintaining a cool environment, are also crucial.

Epidemiology

CU is more common in young adults, with a peak incidence in the second and third decades of life. It affects both genders, though some studies suggest a slightly higher prevalence in males.

Prognosis

The course of CU is highly variable. In some patients, symptoms may resolve spontaneously over time, while in others, the condition may persist for years.

References

1. Zuberbier, T., Aberer, W., Asero, R., et al. (2018). The EAACI/GA²LEN/EDF/WAO Guideline for the definition, classification, diagnosis, and management of urticaria. Allergy, 73(7), 1393-1414.
2. Maurer, M., Weller, K., Bindslev-Jensen, C., et al. (2011). Unmet clinical needs in chronic spontaneous urticaria. A GA²LEN task force report. Allergy, 66(3), 317-330.

See Also

• Urticaria
• Allergy
• Dermatology