- Continuous daily treatment or prophylaxis (other than topical medications) for 6 months duration or more within the last 5 years of a common minor illness such as reactive airway disease, allergic rhinitis/conjunctivitis, or atopic dermatitis (Volunteers with a history of a common minor illness who have required intermittent use of therapeutic or prophylactic medications for less than or equal to 6 months in the last 5 years or for more than 6 months but more than 5 years ago are eligible).