A viral cause has been hypothesized for Pityriasis rosea Gibert (PRG) since its symptoms are similar to those of other prevalent infectious children disorders, but no agent has been discovered as of yet. Here, researchers presented the results of photochronography, virology, and immunology studies conducted on 4 children with PRG and 2 with recurrent varicella. Between April 2012 and May 2016, a pediatric clinic saw 6 kids complaining of skin rashes. Skin lesions were photographed, blood, lesions, and/or nasal lavage samples were collected, and skin tests were performed to evaluate cell-mediated immunity to varicella-zoster virus (VZV). About 2 out of 4 PRG patients were found to have herald patches. There was no evidence of virulent VZV in any of the samples tested. Nonetheless, VZV-DNA was found in the skin lesions of 3 PRG patients. In addition, about 5 patients showed VZV-specific IgG antibodies during the acute phase, and 5 patients had positive skin tests. In PRG patients whose immunity had dropped below the threshold, high IgG antibody titers to VZV at rash initiation suggested that they were already growing at the appearance of the rash and that reinfection with VZV must have occurred during the prodromal stage or several weeks before the rash manifestation. Findings point to novel pathogenesis of PRG, which may explain the observed discrepancies between different hypotheses about the sites of viral entry and replication, the incubation period, and the differences in the clinical course of PRG from the prodrome through recovery.

Source: journals.lww.com/pidj/Abstract/2022/09000/Overlapping_Signs_and_Symptoms_Between_Recurrent.4.aspx