Chronic urticaria and angioedema
Marcus Maurer, Professor of Dermatological Allergology and Director of Research, Charité University Hospital, Berlin
Urticaria is one of the most difficult conditions in allergy to manage. It can dramatically affect the patient's quality of life yet most patients think that there is no treatment. Nearly all urticaria will resolve naturally, eventually, but this can take up to seven years and the need is to keep the patient symptom free during that period.
Symptoms and diagnosis
The symptoms of urticaria are 'wheal and flare' (raised, extremely itchy bumps) plus angioedema (swelling), normally together although they can appear separately. Both symptoms can also be symptoms of other conditions although these are very rare.
The condition nearly always appears in later life, not in childhood.
Urticaria is hard to treat as the cause is rarely unknown – although it is never caused by an allergy so skin prick testing is not helpful. However, induced (as opposed to spontaneous) urticaria can be triggered (but not caused) by:
Spontaneous urticaria appears to be caused by:
• auto reactivity – approximately 20% of cases – when something in the body reacts to something else in the body, often to something circulating in the blood;
• bacterial infection – approximately 25% of cases. Around 50% of us carry bacterial infections but they do not trigger urticaria. If infections are eliminated, around 50% of spontaneous urticaria sufferers will benefit;
• intolerance – approximately 29% of cases. This intolerance is never to food but may be to additives or preservatives. There are no tests so elimination of the most likely substances (all drugs that can induce urticaria, pseudo allergens and histamine) for at least 14 days followed by a challenge is the only way to identify an intolerance. Again, around 50% of spontaneous urticaria sufferers will benefit.
• Find and eliminate the cause/triggers if possible.
• If this is not possible, treat with non-sedating anti-histamines.
• Anti IgE drugs.