Does influenza subtype H1N1 have a place in the etiology of pityriasis rosea?

Introduction Pityriasis rosea (PR) is an acute, inflammatory skin disease of unknown cause. Various infectious agents including viruses have been proposed as causative agents and presence of influenza subtype H1N1 was shown in case reports with PR, but the relation was not conclusive. We hypothesited that there may be a relation between PR and H1N1, since both of them are prevalent in the same period as winter or season transitions. Aim To investigate the effect of the H1N1 virus in PR in this study. Material and methods Twenty-one female and 12 male PR patients who applied to Kırıkkale University Faculty of Medicine Hospital Dermatology Outpatient Clinic were included in the study. Influenza subtype H1N1 IgM and IgG antibodies were detected by enzyme immunoassay (EIA) in sera of patients; tissue biopsy specimens were examined for influenza subtype H1N1 RNA by PCR. Results Seven (23%) of the 33 patients had positive IgM and IgG antibodies. Influenza subtype H1N1 RNA was not detected in the tissue samples of 33 PR patients. Conclusions According to the results of this study, we can say that influenza subtype H1N1 does not play a role in PR etiology.