Efficacy of Baricitinib In Treatment of Delayed-Type Hypersensitivity Versus Irritant Skin Reactions in Healthy Adult Male Subjects

Inclusion Criteria: * Males 18-40 years of age at the time of signing the informed consent document * Understand and voluntarily sign an informed consent document prior to any study related assessments/procedures being conducted * Able to adhere to the study visit schedule and other protocol requirements * Must be in good health as judged by the Investigator, based on medical history and physical examination, and no laboratory abnormalities Exclusion Criteria: * Any known severe allergies to yeast products * Currently active skin diseases such as psoriasis, atopic dermatitis, allergic contact dermatitis or irritant contact dermatitis * Inability to understand informed consent * Any medical condition that the investigator feels would interfere with study * Any abnormalities on physical exam or screening laboratory studies (to progress to Part II) * Agree to discontinue use of prohibited medications at least 4 weeks prior to screening: topical corticosteroids, oral or injectable systemic steroids, systemic immunomodulators (cyclosporine, methotrexate, etc.), oral or topical antihistamines * Positive reaction to tuberculin test (PPD) or negative control * Negative reaction to initial skin testing for Candida, Trichophyton, or Sodium Laurel Sulfate