Co-occurrence of psoriasis, vitiligo, and lichen planus in a single patient

Abstract

Psoriasis is a common autoimmune skin disease affecting around 2%–3% of the world population. The disease has an autoimmune and complex genetic background. It may be associated with other autoimmune diseases such as vitiligo, lichen planus, discoid lupus erythematosus, and alopecia areata as reviewed in the literature. There are few case reports about the co-occurrence of one or two autoimmune diseases. Many speculations have been put forward about the pathogenesis of these conditions, but T-cell-mediated autoimmunity and true Koebner phenomenon background play a common etiological cause of co-occurrence of psoriasis, lichen planus, and vitiligo. We report a 9-year-old female patient who presented with psoriasis, lichen planus, and vitiligo lesions. Interestingly, she developed psoriatic plaques on the vitiligo patches in the knee. Histopathological diagnosis was consistent with the concurrence of psoriasis, lichen planus, and vitiligo.

Keywords

• Autoimmunity
• co-occurrence
• Koebner phenomenon
• lichen planus
• psoriasis
• vitiligo