A viral exanthem is a rash associated with a virus; it may be caused by an immune overreaction or by toxins released by the virus. It is usually widespread across the body and can vary in characteristics depending on which virus is responsible. Some cases are self-limiting and resolve with the virus, while others may require specific treatment. A medical provider can examine the patient to determine the cause and make recommendations for treating the underlying issue and addressing the rash.
Young children in particular are very prone to viral rashes. Mild rashes may simply cause skin flushing and some spotting, while severe rashes may include large welts which can itch and ulcerate, oozing fluids and exposing the underlying tissue. Chickenpox is a classic example of a common childhood illness that can cause a viral exanthem. As the patient recovers, the rash will start to resolve, although some scarring may remain if the patient scratched at the sores while the virus was active.
Measles, scarlet fever, staph infections, and roseola, among others, can also cause a viral exanthem. Some of these conditions require more aggressive treatment because they can present a health risk to the patient; high fever associated with some viral infections, for example, can cause brain damage, and in cases may lead to coma and death if it is not addressed. Vaccinations are available for some dangerous viruses known to cause rashes, allowing patients to prevent infections and the uncomfortable rashes that sometimes accompany them.
Rashes can be itchy or painful and a viral exanthem may require treatment with steroids and other topical ointments to reduce inflammation and make the patient feel more comfortable. Preparations of calamine lotion and similar products can also limit itching, as can bathing in baking soda or oatmeal to soften the skin and reduce irritation. If a patient starts scratching at a rash, there is a risk of causing infection, and it may be helpful to wear long clothes or gloves at night to prevent absentminded scratching.
One of the most infamous causes of a viral exanthem is believed to be extinct in the wild. The smallpox virus famously causes an eruption across the patient’s body as it progresses, and the scabs from the rash can sometimes contain live viruses that can infect others. With an aggressive worldwide vaccination campaign in the 20th century, nations worked together to eradicate this killer disease, although samples remain extant in research facilities.