Multiple Rising Dose Study of MK-6194 in Participants With Atopic Dermatitis (MK-6194-008)

The main inclusion and exclusion criteria include but are not limited to the following: Inclusion Criteria: * Clinical diagnosis of atopic dermatitis for at least 6 months prior to the Screening visit. * Atopic dermatitis is of at least moderate severity. * History of inadequate response to a stable (≥1 month) regimen of medium to high potency topical corticosteroids or calcineurin inhibitors as treatment for atopic dermatitis within 6 months before the screening visit. * Body Mass Index (BMI) ≥18 and ≤38 kg/m2 at the screening visit. Exclusion Criteria: * Concurrent significant skin disease other than atopic dermatitis (such as psoriasis) or a concurrent clinically significant disease. * Significant organ dysfunction that is unstable or inadequately treated within 6 months prior to Screening. * History of cancer (malignancy), with the exceptions: of adequately treated nonmelanomatous skin carcinoma or carcinoma in situ of the cervix or; other malignancies that have been successfully treated with appropriate follow up. * History of myocardial infarction, congestive heart failure, uncontrolled arrhythmias, cardiac revascularization, stroke, uncontrolled hypertension, or uncontrolled diabetes within 6 months of Screening. * History of organ or tissue allograft. * History of symptomatic herpes zoster within 16 weeks of randomization, or any history of disseminated herpes simplex, disseminated herpes zoster, ophthalmic zoster, or central nervous system (CNS) zoster. * Major surgery within 3 months prior to the screening visit or has a major surgery planned during the study. * Received a live or attenuated virus vaccine within 4 weeks prior to the Screening visit or intends to receive live or attenuated virus vaccination during the course of the study and for 12 weeks after the last dose of study drug. * Currently receiving any chronic systemic (oral or intravenous) anti-infective therapy for chronic infection (such as pneumocystis, cytomegalovirus, herpes zoster, or atypical mycobacteria).