Symptoms
Urticaria is a skin disorder that manifests itself in the following symptoms:
- Temporary wheals with a diameter of millimeters to centimeters, which recede on their own within minutes to hours.
- Itching, burning and redness of the skin.
- Angioedema, which is a swelling of the lower skin or mucosal tissue that may be accompanied by pain
Causes and triggers
Urticaria is a heterogeneous condition with variable causes and triggers. Spontaneous urticaria:
- Spontaneous acute or chronic urticaria without an identifiable cause.
Physical causes:
- Cold: cold air, water, wind, food, objects see under cold urticaria.
- Mechanical pressure exerted, shear forces, vibration: the wheals appear some hours delay.
- Heat: locally supplied heat, for example, by a warm object on the skin.
- Sun: UV or visible light: solar urticaria, rare.
- Increase in body temperature: e.g., during stress, showering, bathing or exercise see under Cholinergic Urticaria.
- Sports (exertion-induced urticaria): occurs during physical exertion shortly after eating.
- Contact with water: aquagenic urticaria, very rare.
Allergy or pseudoallergy:
Emotional Urschen:
- Stress and excitement see under Cholinergic Urticaria.
Causes
The skin responds to the release of messenger substances from mast cells and neurons: Histamine, leukotrienes, prostaglandins, neurokinins and tachykinins.
Complications
Anaphylaxis, which is a generalized allergic reaction with respiratory distress, bronchoconstriction, drop in blood pressure (hypotension), collapse, and oedema.
Differential diagnoses
The different types of urticaria must be distinguished on the basis of characteristic features. Different types may also occur simultaneously in one person.
Nonpharmacologic treatment
Avoid triggers, e.g., allergens, high or low temperature, stress.
Drug treatment
Antihistamines:
- Are antipruritic, antiallergic, and anti-inflammatory, e.g., cetirizine, loratadine. A high dose is recommended for acute urticaria.
Glucocorticoids:
- Are anti-allergic, anti-inflammatory and secondary antipruritic.
Skin care products:
- Like hydrolotions to soothe the skin and light cooling.
Mast cell stabilizers:
- Ketotifen, cromoglicic acid
Leukotriene antagonists:
- Montelukast, zafirlukast; not approved for this indication.
Others, depending on type:
- For example, sunscreen for prevention in urticaria triggered by sunlight.
For the treatment of itching: see under the article itching.
