Viral exanthem , also known as non-specific viral rash, is usually a red (erythematous) rash caused by a viral infection. Many viruses can cause a similar-appearing rash, so it is difficult to tell which one is the culprit.
Many viruses cause viral rashes, but it is note worthy that the Epstein-Barr Virus (EBV) & the Herpes Simplex Virus I (HSV-1) frequently flare up with stress especially in periods of high anxiety. Both viruses belong to the herpes family of viruses which also include cold sores, chickenpox or varicella, shingles or herpes zoster (VZV). But EBV and HSV-1 are harmless. They each infect about 90% of the human population. They are neurotropic and neuroinvasive viruses; they enter and hide in nerve cells, accounting for their durability in the human body, because the immune system can not go after them. These viruses live dormant (non-active and non-infectious) within cells but only come out of the cells on rare occasions, such as when the body is under stress.