Prospective study of patch testing in patients with vulval pruritus.

Forty-three patients with the primary complaint of vulval pruritus were recruited to take part in this prospective patch-testing study. A detailed questionnaire was administered to each and patch testing to an extended battery of allergens was undertaken. This included the European standard series, preservatives, corticosteroids and a battery of common over-the-counter topical vulval treatments. Analysis of demographic data and prior treatments used, and various other parameters, were studied in the context of patch-test results. This prospective study reports a very high rate of contact sensitivity in patients presenting with vulval pruritus, with 81.4% of those tested having at least one contact allergen detected. One or more clinically relevant allergens were found in 44% of the subjects patch tested. The variables found to predict a greater likelihood of a contact allergy were a biopsy diagnosis of vulval dermatitis, the use of multiple topical treatments, sexual inactivity and patients with severe pruritus on a self-reported scale. Most importantly, many clinically relevant allergens these patients reacted to were outside the European standard series. This highlights the need for an extended series in this patient population.