Evaluating the Safety and Tolerability of Baricitinib in Patients With Job Syndrome With Lupus-Like Disease and/or Atopic Dermatitis

Background: Autosomal dominant hyper-IgE syndrome (HIES), also called Job syndrome, is a genetic disorder that affects the immune system. It can cause skin and lung infections and problems with blood vessels, connective tissues, and bones. People with HIES often have lupus-like disease or atopic dermatitis (skin rash). Researchers want to know if a drug approved to treat other immune system diseases (baricitinib) can help people with HIES. Objective: To test baricitinib in people with HIES with lupus-like disease or skin rash. Eligibility: People aged 12 years and older with HIES with lupus-like disease or skin rash. Design: Participants will have 5 clinic visits, 4 remote visits, and 2 phone visits in 9 months. Participants will be screened. They will have a physical exam with blood and urine tests. They will have tests of the speed and pressure of blood flow through their body: Blood pressure cuffs will be placed on each arm and leg; electrodes will be placed on the wrists and a microphone on the chest. The study has a 3-month lead-in period. Participants will not take the study drug during this time. They will continue with their usual medical care. They will have 2 phone calls with the study team. Baricitinib is a tablet taken by mouth. Participants will take 1 or 2 tablets by mouth every day for 6 months. They will start with a low dose and may increase to a higher dose. Blood and urine tests will be repeated during each study visit. Other tests may also be repeated during some visits. A skin sample may also be taken....