A new standardized method of evaluating cutaneous irritation from topical medications.
We used a new technique to evaluate and compare cutaneous irritation from various topical medications. Twenty participants with corticosteroid responsive dermatoses were enrolled. Three target areas of unaffected skin were abraded. A negative control (petrolatum ointment) a positive control (an over the counter [OTC] anti itch preparation containing benzyl alcohol) and a test product (fluticasone propionate lotion 0.05% were each applied to separate targetareas on the legs. Participants rated the irritation of each target area using a 10 point scale (1 [no symptoms] to 10 [intolerable burning/ stinging requiring removal of the medication] The mean irritation scores for petrolatum ointment, the OTC anti itch preparation, and fluticasone propionate lotion 0.05% were 1.20, 6.15, and 2.05, respectively. The difference in irritation between the OTC anti itch preparation and fluticasone propionate lotion 0.05% was highly significant (P .0001) The difference in irritation between the OTC anti itch preparation and petrolatum ointment also was highly significant (P .0001) The difference in irritation between fluticasone propionate lotion 0.05% and petrolatum ointment also was statistically significant (P .0104) Irritation scores were then standardized on a 10 point scale, with the irritation score of the negative control given a value of 1.00 and the irritation score of the positive control given a value of 10.00. The standardized irritation score of the test product, fluticasone propionate lotion 0.05% was calculated to be 2.55. Our assay was able to detect and quantify even minimal cutaneous irritation secondary to application of topical medications.
Cutis