Psoriasiform graft-versus-host disease distributed along Blaschko's lines

This case presents an unusual manifestation of cutaneous chronic graft-vs-host disease (cGVHD) mimicking psoriasis along Blaschko's lines. Such a presentation may pose a particular challenge to providers as it is quite rarely reported, and, therefore, it is possibly misdiagnosed. cGVHD may mimic psoriasis and should be considered in any patient previously transplanted even with a previous history of psoriasis. A Blaschkoid pattern of cGVHD is unusual and may be the manifestation of an immune reaction unveiling a previously masked mosaicism.