British Association of Dermatologists: Urticaria Guidelines

Overview / Definition Urticaria, commonly known as hives, is an inflammatory skin condition characterized by the sudden appearance of raised, itchy welts (wheals) on the skin. These lesions can vary in size and may be associated with angioedema, which involves deeper swelling of the skin. Urticaria can be classified into acute (6 weeks) based on the duration of symptoms. Epidemiology Urticaria is a prevalent condition affecting approximately 20% of the population at some point in their lives. The incidence of chronic urticaria is estimated to be about 1% of the population, with a higher prevalence in women than men. Urticaria can occur at any age but is commonly seen in young adults. Pathophysiology / Mechanism The pathophysiology of urticaria involves the degranulation of mast cells and the release of mediators such as histamine, leukotrienes, and prostaglandins. This process can be triggered by various stimuli, including: Allergic reactions (food, drugs) Infections (viral, bacterial) Physical stimuli (pressure, temperature changes) Autoimmune mechanisms (e.g., chronic spontaneous urticaria) The mediators released lead to increased vascular permeability, resulting in the formation of wheals and associated pruritus. Clinical Presentation Patients with urticaria typically present with: Raised, itchy wheals that may appear and resolve rapidly ( Angioedema, particularly around the eyes and lips Flushing or erythema in some cases Symptoms may worsen with heat, stress, or exercise It is important to note that urticaria does not usually cause scarring, and the lesions may change location frequently. Diagnosis / Workup The diagnosis of urticaria is primarily clinical, based on patient history and examination. Key components of the workup include: Detailed History: Duration of symptoms, potential triggers, associated symptoms (e.g., abdominal pain in cases of food allergies). Physical Examination: Observation of wheals and angioedema. Laboratory Tests: Generally not require