Prurigo pigmentosa successfully treated with low-dose isotretinoin

Prurigo pigmentosa (PP) is an uncommon inflammatory disease with pruritic reddish papules, papulovesicules or vesicules that are symmetrically localized on the trunk and nape, accompanied by reticular hyperpigmentation. Currently available therapeutic options seem somewhat unsatisfying. Herein, we report an 18-year-old female with PP successfully treated with low-dose isotretinoin.

The patient presented with a symmetrical pruritic eruption on the lateral sides of her trunk with erythematous papules on a hyperpigmented background. Based on the typical clinical and associated histological findings, the patient was diagnosed as PP and a treatment with low-dose isotretinoin 0.3 mg/kg/day (20 mg/day) was started.

After a total of 3 months of 20 mg/day isotretinoin therapy, all erythematous macules and papules resolved and the residual pigmentation had almost disappeared.

Low-dose isotretinoin is not only adequate for the improvement of erythematous lesions, it also helps resolve the reticular hyperpigmentation of PP. Further studies are needed to observe the efficacy of isotretinoin in the treatment of PP.