[Epidemiology of urticaria diseases]

In a prospective analysis, all patients presenting with urticaria in the practices of a general practitioner and a dermatologist and at a university clinic in the course of a year were ascertained and underwent diagnostic examination according to a uniform scheme. Urticarias are common skin diseases, affecting, at a modest estimate, about 1.3% of the population. Of all the general practitioner's patients about 3% had one of the many types of urticaria. The same percentage was found in the dermatologist's practice and among the patients attending the university clinic. The incidence of the different types of urticaria differs considerably at the different levels of medical care. This may be due to the fact that the patients are referred to a specialist or to a clinic only when the diagnosis or treatment is problematic. Half the general practitioner's urticaria patients suffer from physical urticarias (this includes the minor variants that do not necessarily require medical care). In the clinic, however, only a quarter of all patients with urticaria had physical variants. Patients with chronic urticaria accumulate in clinics because they have been referred for diagnosis and therapy. Predominantly young people were affected by physical urticaria, the peak being between 10 and 40 years. Patients with chronic "endogenous" urticaria were significantly older. About 30% of all patients also had angio-oedema, at least temporarily. Isolated swelling without urticaria occurred in only 3.9% of all patients. In urticaria, there was a slight female predominance: of all patients with physical urticaria, 61.1% were female, and the corresponding figure for nonphysical types was 53.6%. An almost equal sex distribution was found in chronic urticaria (51.9% female). In our prospective study patients presenting with urticaria only as a minor symptom was also ascertained. Many minor variants of physical urticaria were seen in these patients. In the dermatological practice, urticaria was diagnosed incidentally in 6-8% of cases. In the clinic, however, 20% of the physical urticarias and 10% of the acute nonphysical urticarias were recorded as incidental findings.