Pityriasis rosea following human papillomavirus vaccination.

We read with great interest the review by Gonçalves et al.1 about safety, tolerability and side effects of human papillomavirus (HPV) vaccines, discussing the most frequently reported events related to the vaccine. We agree that safety is not a major barrier to vaccination since most of the reported adverse events have been mild or moderate in intensity. We would like to describe two patients who developed pityriasis rosea (PR) following the last dose of the quadrivalent HPV vaccine. To our knowledge, they are the first two cases of PR secondary to HPV vaccine. The first of our patients was a 17-year-old woman who presented with a typical PR, which developed one month after the third dose of HPV vaccination. The exanthema, preceded by general malaise and headache, started with a herald patch on the trunk and progressed with secondary eruptions on trunk, arms and neck two weeks later. Routine investigations yielded unremarkable results. Serology disclosed IgG (1/160) and IgM (1/320) antibodies against human herpesvirus 7 (HHV-7) and IgG antibody against human herpesvirus 6 (HHV-6) (1/40). HHV-7 DNA in plasma (170 genome equivalents/mL) and in peripheral blood mononuclear cells (PBMCs) (657 genome equivalents/mL) were found by calibrated quantitative real-time polymerase chain reaction, as reported.2 HHV-6 DNA was neither found in plasma nor in PBMCs. Her lesions and symptoms gradually improved in the following eight weeks. After recovery, HHV-7 DNA was not any longer detected in plasma. Our second patient was a 20-year-old woman who developed a typical PR two months after the third dose of HPV vaccination. The skin eruption was preceded by headache, inability to concentrate, and insomnia, initiated over the trunk and then spread to the abdomen and neck without a herald patch. Routine investigations turned out normal. IgG antibodies against HHV-6 and HHV-7 were present (1/320 and 1/160, respectively) whereas IgM was negative. HHV-6 and HHV-7 DNAs were positive in plasma (137 and 85 copies/mL) and in