Viral illness is the most common cause of a sudden rash on your infant's skin, according to Dr. Sears, an associate clinical professor of pediatrics at the University of California, Irvine. Several viral illnesses can cause a rash accompanied by a fever. In most cases these viruses are harmless and clear on their own. None the less, always call your pediatrician if your child has a fever, with or without a rash.
Chicken Pox
Chicken pox is caused by the varicella virus and is commonly contracted by children under the age of 12. The rash begins as a few red spots or bumps, accompanied by a fever and flu-like symptoms. The bumps turn into itchy blisters within a day and more bumps appear during the next few days. According to Dr. Sears, by day seven most or all of the blisters are crusted over. Chicken pox symptoms can disappear on their own without treatment; however, your child should be quarantined at home since the infection is highly contagious. Treat the fever with acetaminophen and help relieve itching with Benadryl and oatmeal baths. Children can be protected from chicken pox by the varicella vaccine.
Fifth Disease
Fifth disease, also referred to as "slapped-cheek disease," is a viral infection caused by parvovirus b19. The infection begins with malaise and fever followed by the appearance of bright red rashes on the cheeks. Your infant can also develop a fever. Within a few days, a fine, lacy rash develops and spreads to the rest of your child's body. Fifth disease is highly contagious just before the rashes appear and can be transmitted through saliva, cough or a runny nose. Fifth disease is usually a mild infection that resolves on its own, according to the Centers for Disease Control and Prevention.
Roseola
Roseola, or the sixth disease, is a viral infection common in children between ages 3 months and 3 years. The illness begins with a fever, followed by a flat or bumpy red rash around the neck, back and chest, according to Dr. Sears. Roseola is contagious a few days before the fever begins until a few days after the fever is gone and can be passed via saliva, runny nose and cough. The illness can last from a few days to a couple weeks but is usually harmless. Treat roseola by easing the fever and discomfort with fever and pain medications, rest and fluids.
Viral Exanthem
Viral exanthem is a rash characterized by pink-to-red spots and bumps. The rash first appears on your infant's trunk and then spreads to the extremities. It may or may not cause any itching and can be accompanied by headache, fatigue, fever, loss of appetite and irritability, according to the Skinsight website. If your infant has only mild symptoms, treat her with fever and pain medications at home. However, if your child has a fever higher than 101 degrees, severe headache and stiff neck, seizures, cough, and red eyes, mouth or tongue, call your doctor.
