- Concurrent treatment with immunomodulatory drugs, or exposure to any immunomodulatory drug in the preceding 16 weeks (e.g. corticosteroid therapy equal to or exceeding a dose of 15 mg/day of prednisone for more than 10 days, IL-2, interferon-alpha, methotrexate, cancer chemotherapy). NOTE: Use of inhaled or nasal steroid use is not exclusionary.