Chronic urticaria: a Canadian perspective on patterns and practical management strategies

Chronic urticaria is a common condition and is a source of great frustration to patients. It has been suggested that there may be differences among physicians in their approach to this common clinical entity.

A questionnaire was distributed Canada-wide to allergists, dermatologists, and a selection of practitioners with an interest in alternative medicine. The survey included questions on demographics, epidemiology, causative factors, diagnostic methods, therapeutic strategies, follow-up advice, and efficacy of therapies, with emphasis on personal experience.

The response rates of allergists and dermatologists were 31% and 36%, respectively. There was wide representation from all regions of Canada and from physicians from all age groups, both genders, different types of practice, and years in practice. The reported incidence per month was 13 and 4 patients for allergists and dermatologists, respectively. The prevalence was 199 and 44 patients by allergists and dermatologists, respectively. Comparison of causative factors showed differences in the experiences of the two groups. Diagnostic investigations were requested in a similar pattern with respect to timing. The specific tests ordered by the groups showing statistical difference were complete blood count (CBC), differential, C4 complement, antinuclear antibodies, and IgE antibody assay. Allergists chose the skin prick test (100%) as the most important allergy test. Dermatologists ranked skin prick (50%), radioallergosorbent test (RAST) (20%), and skin patch (30%) as the most important tests. The top six choices of pharmaceutical therapies chosen by the groups were similar, but in a slightly different order. The responders ranked their personal selection of antihistamines according to effectiveness. Hydroxyzine (Atarax) and cetirizine (Reactine, Allegra) were selected as first and second most effective agents by both groups. The results also show effective experience by both groups with nonsedating and sedating antihistamines. Also, doxepin, ketotifen, and cimetidine are used frequently by both groups. The experience of dermatologists in Canada with respect to other modalities including psoralen ultraviolet A (PUVA) therapy, danazol, chelation, calcium channel blockers, and acyclovir is limited and efficacy is ranked either neutral or ineffective. Allergists reported even less experience with these therapies.

Allergists and dermatologists across Canada show interesting similarities and differences in their practical approach to the management of chronic urticaria. With the sharing of this information, these two specialties will be better equipped to effectively manage patients suffering from chronic urticaria.