Regional lymphomatoid papulosis in a child--treatment with a UVB phototherapy handpiece.

Lymphomatoid papulosis (LyP) is a rare skin lymphoproliferative disorder that has been reported only rarely in children. It is included in the World Health Organization classification of cutaneous lymphomas. We report a case of LyP in a 13-year-old Caucasian girl who presented with a 6-month history of recurrent papular lesions on the left upper arm. Histopathologic examination showed a diffuse cellular infiltration of small and medium-sized T lymphocytes CD30+ in the superficial dermis. Treatment was started using a UVB phototherapy handpiece (twice weekly), with resolution of the lesions after 6 weeks of treatment. There was a relapse after 9 months with a good response after six more sessions of treatment. The patient is in good health without lesions after 12 months of follow-up.