Hives, allergies and urticaria

Medical terms

Urticaria, angio-oedema, insect bites

Common terms

Hives, welts, allergies

Overview

Hives are frequently caused by allergic reactions; however, there are many non-allergic causes. The tendency for people to develop allergies is becoming increasingly common with our modern lifestyles and this is particularly prevalent in London and other large cities. Allergies may be responsible in some patient\'s for various skin conditions.  These include eczema, allergic contact dermatitis and urticaria.
Cases of hives lasting less than six weeks (acute urticaria) is maybe the result of an allergic trigger in adults, or due to a viral infection in children. Chronic urticaria (hives lasting longer than six weeks) are rarely due to an allergy.

Symptoms and signs

A skin rash with bright red, raised, itchy bumps. These lesions typically last less than 24 hours in any one place but are characterised by new lesions forming in other areas of the body. More severe cases may progress to urticarial vasculitis where the lesions last longer and may resolve with bruising.

Treatment

Chronic urticaria can be difficult to treat and some percentage of the population is treatment resistant with medication losing its effectiveness and requiring new medication to control attacks. Occasionally immunosupressive medication is needed for the more resistant cases. Effective diagnosis and a knowledge of all the available treatments is key to determining appropriate treatment.