A retrospective study of patch test results from 163 patients with stasis dermatitis or leg ulcers. II. Retesting of 50 patients.

Retesting 50 patients with stasis dermatitis after a period of time (3-25 months) revealed significantly less positive patch test results (p less than 0.05). All procedures were, of course, standardized. The main reasons for this were elimination of the sensitization agents in the interim and testing with a less acute skin condition. Allergens that are difficult to avoid, such as the 'para' compounds and balsam of Peru and related substances, show a higher degree of persistence in subsequent patch testing.