Vitiligo as a Determinant in Biologic Therapy Selection for Psoriasis and Psoriatic Arthritis

Introduction and Objectives: Vitiligo is an autoimmune depigmenting skin disorder that may co-occur with other immune-mediated diseases, including psoriasis and psoriatic arthritis. Immune-pathogenetic studies demonstrate elevated TNF levels in vitiligo lesions, implicating TNF in melanocyte destruction and providing a possible biological explanation for clinical reports linking antiTNF therapy with new-onset or exacerbation of vitiligo in patients with psoriasis. While biologic therapy for psoriasis has revolutionized, optimal agent selection must consider comorbidities[1,2]. This case highlights the clinical importance of vitiligo as a relevant clinical factor in biologic therapy decision-making with the preferential use of IL17 inhibitors over TNF inhibitors in patient with coexisting vitiligo. Materials and Methods: A 68-year-old female with a 15-year history of psoriasis, palmoplantar pustulosis, psoriatic arthritis and longstanding vitiligo presented with worsening skin and joint symptoms. Over the preceding two years, the patient reported progressive dermatologic deterioration, with persistent psoriatic plaques on the lower abdomen, pustules on the soles, and nail dystrophy of the hands and feet. PASI score was 10.5. Depigmented patches consistent with vitiligo had been present for many years and involved multiple areas of the body. No seasonal improvement during summer months, and family history for psoriasis was negative. Systemic treatment with oral methotrexate 10 mg/week was initiated. After 2 months, routine laboratory follow-up revealed markedly elevated hepatic transaminases (ALT 571 U/L, AST 332 U/L). Liver ultrasound was within normal limits. The patient simultaneously reported persistent abdominal discomfort and a bitter taste in the mouth. Clinical and laboratory findings raised suspicion for methotrexate-induced hepatotoxicity, prompting immediate drug discontinuation. Results: Following methotrexate withdrawal, palmoplantar lesions worsened and significantly impaired quality of life (DLQI 20). Considering the patient’s comorbidities - including vitiligo, arterial hypertension, chronic heart failure, and hypothyroidism, an interleukin-17 (IL-17) inhibitor was selected as the preferred biologic therapy for psoriasis and psoriatic arthritis treatment due to its favorable safety profile, particularly in avoiding TNF- inhibitor-associated vitiligo exacerbation. Prior to initiation of biologic treatment, routine laboratory screening for latent infections was advised, including hepatitis B surface antigen (HBsAg), anti-HCV antibodies, and QuantiFERON-TB Gold assay, alongside with a rheumatologist‘s consultation to finalize therapeutic planning. Conclusions: This case underscores the clinical relevance of vitiligo as an important consideration in the selection of biologic therapy for patients with psoriasis and psoriatic arthritis. While TNF- inhibitors remain effective treatment options, they could potentialy to trigger or exacerbate vitiligo. In such cases, IL-17 inhibitors may offer a more favorable alternative. Biologic therapy should be individualized, taking into account comorbid autoimmune conditions such as vitiligo, to minimize the risk of it‘s exacerbation and optimize patient outcomes.