Development of lichen planus and psoriasis on lesions of vitiligo vulgaris.

This paper reports a unique case of coexistence of vitiligo vulgaris, lichen planus and psoriasis vulgaris in a 53-year-old man. Five years after the onset of vitiligo, lichen planus developed on his lower lip. Another 4 years after the onset of lichen planus, he also exhibited psoriasis on his upper arms and trunk. Both the lichen planus and psoriasis occurred on lesions of the preceding vitiligo vulgaris. We discuss potential mechanisms for association of these three dermatoses, including Koebner phenomenon and photodamage.