Pityriasis lichenoides et varioliformis acuta: a rare association with the measles, mumps and rubella vaccine.

The aetiology of pityriasis lichenoides (PL) is unknown. One major pathogenic theory suggests that PL is a lymphoproliferative disease or inflammatory reaction triggered by an antigenic stimulus, such as a virus or other infectious agent. We report the second case of PL et varioliformis acuta (PLEVA) occurring after measles vaccination and the first following the combined measles, mumps, rubella vaccination.