vitiligo is an autoimmune depigmenting skin disorder characterized by milky white macules or patches, with 2% worldwide prevalence. Vitiligo has unexpected course that significantly influences on patient's quality of life and self-esteem.

Multiple medications have been introduced for vitiligo treatment, in this study we work on one of systemic JAK inhibitors

Vitiligo, an autoimmune depigmenting disorder has a worldwide prevalence of 0.5%-2.0%. distinguished by distinct, varying-shaped depigmented macules and patches. Vitiligo is thought to be a benign condition that mostly affects appearance, although it usually has a significant negative influence on patients' quality of life and self-esteem. It may also put them at higher risk of developing skin cancer and sunburn. 85%-90% of cases are generalized vitiligo, also known as non-segmental vitiligo (NSV), which is characterized by a symmetric body distribution. A number of factors contribute to the multifactorial pathophysiology of vitiligo, including metabolic disorders, oxidative stress, hereditary vulnerability, and autoimmune response. Of these, cell-mediated immunity plays a major role in melanocytes destruction .The interferon-gamma (IFN-γ), C-X-C motif chemokine ligands (CXCL9/10), and C-X-C motif chemokine receptor (CXCR3) signaling axis (IFN-γ-CXCL9/10-CXCR3 or ICC axis) has been identified as a critical mediator for the recruitment of autoimmune CXCR3+ CD8+ T cells. High amounts of INF-γ and tumor necrosis factor alpha (TNF-α) are produced by these cells, which encourage melanocytes (MC) detachment and apoptosis. MCs detachment is prevented by inhibiting IFN-γ signaling pathway, which is regulated by Janus kinase-signal transducer and activator of transcription (JAK-STAT). Treatment goals for vitiligo include arresting, re-pigmentation of existing lesions, and maintenance of re-pigmentation. Only generic immunosuppressants, including oral and topical corticosteroids, calcineurin inhibitors, phototherapy, and surgical procedures, are available as the current traditional therapeutics for vitiligo. One of the primary lines of treatment for generalized vitiligo is narrowband ultraviolet B (NB-UVB) phototherapy, which is always enhanced by combining it with other therapies. JAK inhibitors target the JAK/STAT signaling pathway and are now approved to treat many immune diseases. It was reported that individuals with vitiligo treated with JAK inhibitors had higher rates of re-pigmentation especially when combined with ultraviolet or sun exposure. Given IFN-γ signaling is specially mediated by JAK1 and JAK 2. Baricitinib is a small molecule, which mainly targets the JAK1 and JAK2 subtypes, is already used in dermatology to treat inflammatory dermatoses that are caused by JAK/STAT signaling.

The cytosolic calcium-binding S100 protein family has a variety of intracellular and extracellular activities. A damage-associated molecular pattern protein called S100B has been suggested as a gauge of melanocyte cytotoxicity.

Inclusion Criteria:

• active generalized vitiligo patients with body surface area involved >5% excluding hands and feet
• no systemic treatment for vitiligo for the last 3 months or topical treatment received for the last 4 weeks.

Exclusion Criteria:

• acrofacial, acral, segmental or mucosal vitiligo
• patients on another immunosuppressive agent
• patients have other skin conditions (psoriasis, SLE, alopecia areata) that would interfere with evaluations of the effect of study medication on vitiligo.
• patients who suffered from systemic diseases affecting S100B (e.g. Subarachnoid hemorrhage, Alzheimer disease and inflammatory diseases) or from other dermatological diseases affecting S100B level (e.g. malignant melanoma)
• Patients immunocompromised, uncontrolled arterial hypertension, clinically serious viral, bacterial, fungal, or parasitic infection, anemia, history of thromboembolic event, cardiovascular, respiratory, hepatic, gastrointestinal, endocrine, hematological, lymphoproliferative disease, neurological, or neuropsychiatric disorders or any other serious and/or unstable illness.
• Pregnancy and lactation.