Electron microscopic observations on the lesions of herpes zoster with topical application of interferon

The lesions of herpes zoster in three patients were investigated electron microscopically before and after topical application of interferon. In the blister, on the 5th to 7th day after its formation, the following were seen: acantholytic cells with virus particles in the nucleus and cytoplasm, multinucleated cells derived from keratinocytes, edematous and degenerated keratinocytes containing virus particles and tonofibrillar materials, macrophages with many large vacuoles, neutrophils, lymphocytes and Langerhans's cells. After the first application of interferon, the findings for keratinocytes were the same as those of before application and keratinocytes were frequently found adjacent to macrophages. The macrophages were large and had numerons large vacuoles in the cytoplasm. After the second application of interferon, virus particles were often seen in the vacuoles of the macrophages in comparison with that before application. In the cytoplasm of macrophages, acantholytic keratinocytes and tonofibrillar materials were phagocytized. Many virus particles were seen in the vacuoles of some acantholytic keratinocytes. It was concluded from these findings that the macrophages accelerated the phagocytotic activity of the virus particles.