Urticaria and Angio-Oedema.

SUMMARY.— The records of 554 consecutive patients attending hospitals in the Cambridge region with urticaria have been analysed with the aid of a computer. These patients represent only a small minority of all patients with urticaria in the region. In 79%, the aetiology was unknown although in many cases aggravating factors, for example, psychological stress, aspirin, or infection, were detected. A past or family history of atopic disorders was not found more frequently in patients with urticaria than in controls and the course of the disease in patients with a background of atopy did not differ from the remainder, suggesting that an undetected allergy is not responsible for many of these undiagnosed cases. Allergy is relatively more important in acute urticaria and in patients who do not attend hospital. The frequency of attacks and total duration of the disease are different in patients with urticaria alone, angio‐oedema alone and both together but there was little difference in the aetiological factors, supporting the concept that urticaria and angio‐oedema are fundamentally similar. The prognosis is expressed in the form of life tables.