[Histopathologic, ultrastructural, immunologic and virologic study of Gibert's pityriasis rosea].

A complete study of pityriasis rosea (Gibert) has been performed; this study includes: --a pathological and ultrastructural examination of the skin biopsies; --an immunological study: direct and indirect immunofluorescence (seric anti-cutaneous antibodies); --a virological investigation: ultrastructural examination of the specimens, inoculation of homogenized-skin specimens to 3 cellular cultures; --serological investigations for influenza A, B, parainfluenza 1, 2, 3, adenovirus, respiratory syncitial virus, Mycoplasma pneumoniae, ornithosis-psittacosis, Q-fever, herpes-virus, herpes-virus varicellae, cytomegalovirus, Epstein-Barr virus. All viral investigations had a negative result. Virus or virus-like particle has were not detected on the ultrastructural examinations. A viral infective agent cannot be incriminated as the cause of PRG. However, a large number of PRG patients had antibodies for the Epstein-Barr virus early antigen. The authors are carrying on with this particular investigation.