Pityriasis rosea (PR) is an exanthematous disease associated with the endogenous systemic reactivation of human herpesvirus-6 (HHV-6) and human herpesvirus-7 (HHV-7). Oropharyngeal lesions may be associated with the exanthema, but anecdotal evidence suggests that few dermatologists are aware of their occurrence.

Classifying oropharyngeal lesions in PR, establishing their prevalence, and assessing their possible association with different PR forms.

The records of all PR cases diagnosed in the Dermatology Clinic of Genoa University between 2003 and 2016 were retrospectively reviewed to examine sex and age of the patients, PR type, presence of enanthema, systemic symptoms, specific anti–HHV-6 and or HHV-7 serology, and HHV-6 and/or HHV-7 DNA loads.

The oropharyngeal mucosa was carefully examined in 527 patients with PR. Painless oropharyngeal lesions were observed in 149 patients with PR (28%) and classified as erythematomacular, macular and papular, erythematovesicular, and petechial lesions. The petechial and macular and papular patterns were those most frequently observed. There was no statistically significant difference in the levels of HHV-6 and HHV-7 viremia in the plasma of patients with enanthema and those without.

Because this was a retrospective study, biopsies on mucosal lesions were not performed.

Our findings showed that enanthemas are frequently associated with forms of PR different from the classic form.