Urticaria can be classified as acute or chronic. Chronic urticaria is less common compared to acute urticaria and it is defined as urticaria of more than 6 weeks.
Urticaria is due to the release of histamine and other chemical mediators from mast cells in the skin. These chemicals cause vasodilatation and leakage of fluid into the dermis.
Acute urticaria can be triggered by a viral infection, bacterial infection, food allergy, drug allergy or insect bites.
Chronic urticaria usually has an unknown cause. An autoimmune cause is probable. Chronic urticaria can be triggered by infection, heat, tight clothing or drugs.
Symptoms and signs:
Urticaria is usually itchy and last from a few minutes to 24 hours. It can appear as red patches, plaques with a map-like pattern. It can spread fast and cover in a wide area.
When patients experience difficulty in swallowing or breathing, then they need to go to the emergency department immediately as laryngeal edema or bronchospasm may be happening which are life-threatening.
The first-line treatment is the use of non-sedating antihistamine.
In severe cases then ciclosporin may be considered.
Avoid showering or bathing with excessively hot water and do not rub the skin hard. Since these might trigger the onset of urticaria. Avoid alcohol as this is known to induce urticaria. Wear loose and light clothing. Stay in a cool and air-conditioned environment could help to reduce the risk of triggering the urticaria.