Adults with known respiratory allergy/asthma with known skin test sensitization will undergo repeat skin prick testing at 4 areas of both arms (bilateral forearms, bilateral upper arms). Each site will be challenged with up to three known allergens, saline and histamine controls. Mean wheal diameter after 20 minutes challenge will be determined. This is followed by placement of minocycline cream (0%, 1%, 2%, 3%), placed in randomized fashion at each of 1 of 4 skin test sites. Measurement of subsequent wheal diameter will be done at 30 minutes, 60 minutes and 24 hours.~In addition, itch assessment at each site will be done at baseline, 30 minutes, 60 minutes and 24 hours using VAS and questionnaire.
Adults with known respiratory allergy/asthma with known skin test sensitization will undergo repeat skin prick testing at 4 areas of both arms (bilateral forearms, bilateral upper arms). Each site will be challenged with up to three known allergens, saline and histamine controls. Mean wheal diameter after 20 minutes challenge will be determined. This is followed by placement of minocycline cream (0%, 1%, 2%, 3%), placed in randomized fashion at each of 1 of 4 skin test sites. Measurement of subsequent wheal diameter will be done at 30 minutes, 60 minutes and 24 hours.