Vitiligo Arising at the Injection Site of Interferon‐α

A 41-year-old Chinese male presents with vitiligo arising over the bilateral thigh after local subcutaneous interferon (IFN)-α injections for 6 months. Physical examination revealed symmetrical depigmented macules developed at the injection sites, characterized by island-like residual pigmentation within the affected areas (Figure 1). Additional hypopigmented patches were observed on the skin of the lower jaw and ears. Non-segmental vitiligo was made based on clinical findings. Following topical treatment with a calcineurin inhibitor and psoralen tincture as a photosensitizer agent, gradual improvement of the skin lesions was observed. IFN-α serves as a key therapeutic agent in the treatment of chronic hepatitis B, exerting its effects through binding to the type I interferon receptor complex, which subsequently activates the JAK-STAT signalling cascade [1]. IFN-γ has been demonstrated to promote melanocyte detachment and apoptosis via the IFN-γ/CXCL9/10/CXCR3 signalling axis and the JAK-STAT pathway, contributing to the pathogenesis of vitiligo [2]. Consequently, prolonged local application of IFN-α may induce vitiligo through a mechanism analogous to that of IFN-γ. Recent studies have also implicated IFN-α in the progression of vitiligo via activation of the monocyte cGAS-STING-IFN-α/β signalling pathway [3]. Previous case reports have documented vitiligo onset in patients with hepatitis C and Behcet's disease following interferon therapy [4, 5]. Yubin Peng: writing – original draft. Tao Wang: funding acquisition, writing – review and editing. We confirm that the manuscript has been read and approved by all authors. All authors meet authorship criteria, and the manuscript represents honest work. The authors certify that they have obtained all appropriate patient consent. This work was supported by Beijing Key Clinical Specialty Construction Project and National Key Clinical Specialty Project of China. All patients in this manuscript have given written informed consent for participation in the study and the use of their de-identified, anonymized, aggregated data and their case details (including photographs) for publication. The authors declare no conflicts of interest. We used artificial intelligence to help check the grammar and sentences. We have referred to the publisher's policy of use of AI as depicted in information for authors and assume full responsibility for the content of our manuscript, even those parts produced by an AI tool, and are thus liable for any breach of publication ethics. The data that support the findings of this study are available from the corresponding author upon reasonable request.