Case presentation

A 57-year-old woman with a history of eczema as a child initially presented with ill-defined erythematous scaly plaques on the body, consistent with a diagnosis of atopic dermatitis. Due to the large percentage of body surface area affected, she was initiated on dupilumab, with a loading dose subcutaneous injection of 600 mg on day zero, followed by a 300 mg subcutaneous injection every two weeks. At her three-week follow-up appointment, the patient reported diminished efficacy of dupilumab, as she continued to experience full-body flares. Her dermatologist prescribed mometasone 0.1% cream, hydrocortisone 2.5% cream, and Epiceram to use to further manage her flares, in conjunction with dupilumab injections. Three months later, the patient presented with depigmented patches on the left and right metacarpophalangeal joints, consistent with a diagnosis of non-segmental vitiligo (Figure 1). The patient was Fitzpatrick skin type IV. Diagnosis was confirmed clinically with Wood's lamp examination, which demonstrated enhanced fluorescence of the depigmented patches, and dermoscopy, which showed features typical of vitiligo, including a residual perifollicular pigment pattern. Histopathologic confirmation via skin biopsy was not performed, as the clinical and dermoscopic findings were considered sufficiently characteristic of vitiligo. No autoimmune serologic workup, including thyroid function testing or autoantibody panels, was performed, and the patient reported no family history of vitiligo or other autoimmune disease.

Figure 1: Bilateral hand vitiligo that developed three months after dupilumab initiation, showing characteristic depigmented patches on the dorsal aspect of both hands. Baseline involvement was more extensive on the right hand than the left hand.

The patient denied any prior history of vitiligo or autoimmune disease, and this was her first exposure to an injectable biologic medication. She was prescribed tacrolimus 0.1% ointment and ruxolitinib in an effort to reverse the vitiligo and was instructed to apply tacrolimus to one hand and ruxolitinib to the other hand, allowing for a side-by-side comparison of treatment efficacy (Figure 2).

Figure 2: Clinical improvement at two months after dupilumab discontinuation and initiation of targeted therapiesThe left hand received topical tacrolimus 0.1% ointment; the right hand received topical ruxolitinib cream. Both hands were treated concurrently with systemic nemolizumab. Repigmentation is visually more pronounced on the ruxolitinib-treated right hand, though this hand also had greater baseline involvement (Figure 1).

Following the emergence of vitiligo-like depigmentation suspected to be associated with dupilumab use, the patient was transitioned to nemolizumab. Within eight weeks of switching biologic medications and maintaining consistent use of ruxolitinib and tacrolimus, the patient experienced significant improvement in her vitiligo, with more repigmentation noted on the hand treated with ruxolitinib.