Cytomegalovirus is a herpes virus that is ubiquitous in human populations.
Viral infection causes cell necrosis.
There is a steady increase in the number of individuals with antibodies in the serum, and this number takes a significant jump at the time of adolescence, presumably due to transfer of virus through the oral route. In the skin, cytomegalovirus can cause sharply punched-out ulcers. Histologically, affected cells are enlarged, with large intranuclear inclusions with a typical halo around them. There is relatively little acute inflammatory reaction to the viral infection. Cells that are productively infected and bearing inclusions tend to be significantly larger than surrounding cells.