13. Subjects using topical or systemic medication within 14 days before the study entry, which could interfere with study assessments. This includes but is not limited to the following: anti-inflammatory drugs (e.g. topical and systemic corticosteroids and systemic antihistamines), anti-acne drugs, topical and oral retinoids, topical antibacterial agents to the face, and any immunosuppressive drugs. Ongoing oral medications not expected to interfere with study assessments are allowed if the subject is on a stable regimen.