Could a common arthritis drug tame a rare, fatal blood vessel disease?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

* INCLUSION CRITERIA: In order to be eligible to participate in this study, an individual must meet all of the following criteria: * Provision of signed and dated informed consent form by the subject or Legally Authorized Representative (LAR). * Stated willingness to comply with all study procedures and availability for the duration of the study. * Male or female, aged 18 or older. * Subjects diagnosed with systemic Degos disease, who manifest neurologic abnormalities observed clinically, radiologically or in abnormal laboratory findings. * Ability to take oral medication and be willing to adhere to the baricitinib regimen. * For female patients of reproductive potential, non-pregnant, non-breastfeeding: agree to use of highly effective contraception for the duration of the study and 30 days after the last dose. * Ability of subject or LAR to understand and the willingness to sign a written informed consent document. EXCLUSION CRITERIA: * Active infection not responding to appropriate therapy * Hemoglobin \<7 g/dL * Platelet counts \< 50 K /mcL * Neutropenia (ANC \<0.5 x k/mcL) * Lymphopenia (Absolute Lymphocyte Count \[ALC\] \<0.2x k/mcL) * Liver function tests (LFTs \> 2x time upper limit of normal) * Estimated Glomerular Filtration Rate (eGFR)/Creatinine (Cr \< 30 mL/min) * Have experienced any of the following within 12 weeks of screening: VTE (DVT/pulmonary embolism \[PE\]), myocardial infarction (MI), unstable ischemic heart disease, stroke, or New York Heart Association Stage III/IV heart failure. * Have had symptomatic herpes zoster infection within 12 weeks prior to a enrolling in the study . * Have had household contact with a person with active TB and did not receive appropriate and documented prophylaxis for TB. * Have evidence of active TB or latent TB * Have been exposed to a live vaccine within 12 weeks of baricitinib treatment or are expected to need/receive a live vaccine during the course of the study * No gadolinium based contrast agent exposure is permitted if eGFR \< 30 mL/min/1.73m\^2 using the CKD-EPI equation measured within 5 days . * Breast feeding * Pregnancy * Uncontrolled malignancy