Lichen-planopilaris-like scarring pattern in a patient with alopecia and pityriasis rubra pilaris.

Pityriasis rubra pilaris (PRP) is an erythematous-desquamative dermatitis that is sometimes associated with non-scarring alopecia. Despite the fact that the disease can be disfiguring, scarring alopecia has rarely been described in this disease. Here, we present a 69-year-old woman who developed an erythrodermic episode of PRP associated with telogen effluvium that left an area of persistent alopecia of the scalp and resulted in hair loss in the eyebrows. The biopsy of that area of the scalp demonstrated a scarring alopecia with lichen-planopilaris-like features. Despite this histopathology, the alopecia responded well to treatment. This finding expands the context in which lichen planopilaris features can be found and demonstrates their good prognosis under early treatment.