Pityriasis rubra pilaris sensitive to narrow band-ultraviolet B light therapy

Pityriasis rubra pilaris (PRP) is a rare skin condition which typically presents in adults as red-orange plaques with islands of sparing, perifollicular keratotic papules, waxy palmoplantar keratoderma, and erythema with fine, diffuse scale. Currently, there are no well-established treatment guidelines for this condition. This is party due to a lack of universally effective treatments for PRP, with some cases being resistant to multiple topical and systemic therapies. Systemic retinoids have been used with some success. Several phototherapy regimens have lead to variable results. The authors present a case of PRP, unresponsive to 6 month treatment of isotretinoin, that was subsequently treated with narrow-band ultraviolet B (NB-UVB) light therapy with complete resolution after four months of light treatment. The observed clinical benefit may encourage future phototesting and consideration of NB-UVB light therapy in recalcitrant PRP cases.