A Pilot Study of Transdermal Application of Diphenhydramine to the Nasal Ala in Patients with Allergic Rhinitis and Asthma.

BACKGROUND
To date, topical allergic rhinitis drugs must be applied intranasally. We studied the efficacy, safety, and impact on co-existing asthma symptoms of transdermal delivery of diphenhydramine through the nasal ala.


METHODS
We enrolled outpatients with symptomatic allergic rhinitis and asthma who were on stable medication for at least 4 weeks. Patients applied diphenhydramine ointment, 0.07 g measured with weighing spoon (0.7 mg diphenhydramine), to the nasal ala twice a day for 2 weeks, followed by 2 weeks' washout. Effects were assessed with the Japanese Allergic Rhinitis Standard Quality of Life Questionnaire (JRQLQ) and Self-assessment of Allergic Rhinitis and Asthma (SACRA) and Asthma Control Test (ACT) questionnaires.


RESULTS
Ten patients participated in the study. Two patients experienced acute exacerbation of asthma during the intervention phase, but no other adverse effects occurred. Self-assessments indicated efficacy in treating nasal symptoms in 5 patients. No significant changes in scores were seen, although mean total JRQLQ score showed a numerical improvement (from 34.3 [21.0] to 14.4 [8.8]; P = 0.0547). Asthma symptoms improved subjectively in 2 patients.


CONCLUSIONS
The efficacy of transdermal application of diphenhydramine on the nasal ala for treating allergic rhinitis was not conclusive, but appears to be effective in certain patients.