Dupilumab as a novel therapeutic option for lichen planus pigmentosus: a case report

Abstract

Lichen planus pigmentosus (LPP) is a form of lichen planus. It typically presents with pigmented, persistent skin patches. The etiology of LPP remains unclear, and there is no standardized or consistently effective treatment. Investigation of dupilumab, a monoclonal antibody not previously reported in the literature for LPP, may provide a new treatment option for disease management. A 42-year-old woman presented with progressive, pruritic, violaceous to dark brown patches on the neck, chest, and upper back for the past year. A biopsy from the neck and arm confirmed epidermal atrophy and pigment incontinence consistent with LPP. Multiple therapies were tried, including topical tacrolimus, oral cyclosporine, oral isotretinoin, narrowband ultraviolet B phototherapy, and oral dapsone, but the patient did not improve. Thus, off-label dupilumab was initiated with a 600 mg loading dose followed by 300 mg every two weeks. After three months of dupilumab therapy, the patient achieved complete resolution of pruritus and lightening of pigmented lesions. No new lesions developed, and the treatment was well tolerated. This significant clinical response to dupilumab following failure of previous therapies suggests potential efficacy in refractory LPP. The rapid response to dupilumab indicates that the T-helper 2 (Th2) immune pathway, particularly interleukin-4 (IL-4) and interleukin-13 (IL-13) signaling, may contribute to LPP pathogenesis. This is the first case of LPP successfully treated with dupilumab, encouraging the need for further research to judge the drug's efficacy.