A wide variety of rashes are seen in children, most of them posing only minor health concerns and all of them traceable to specific underlying causes. Common causes of such rashes, according to Livestrong.com, include skin disorders, allergic reactions, overheating and both bacterial and viral infections. Common viral rashes seen in children, according to eMedicine.com, include varicella (chickenpox); measles and rubella; fifth disease; roseola infantum; and enteroviral illnesses, including herpangina and hand-foot-and-mouth disease.
The first sign of this viral infection is usually a sprinkling of red spots or bumps which easily can be mistaken for insect bites. More and more bumps will follow, and the older bumps will probably turn into blisters. Children usually become feverish soon after this virus takes hold, according to AskDrSears.com. As the illness progresses, some of the older lesions will develop a crusty covering. Infected children are likely to experience itching in addition to fever, and in rare cases sore throat or systemic illness may occur. Children with varicella usually are contagious for a period of 8 to 10 days, according to the Medical College of Georgia's Continuity Clinic Notebook.
Measles and Rubella
Both these viral infections are seen less often now that most children are protected through the widespread use of the MMR vaccine that provides immunity from measles, mumps and rubella. The first symptoms of measles are more akin to those seen with a bad cold or flu---high fever, nasal congestion, lethargy, coughing and eye redness. The illness's characteristic red rash usually appears on the third or fourth day of infection and may last for seven or eight days. Rubella, also known as German measles, begins with a red or pink rash on the face that soon spreads to the rest of the body. The infection is short-lived, lasting roughly four or five days, and usually causes far less discomfort than measles.
Caused by parvovirus B19, fifth disease also is known as erythema infectiosum and usually causes only minor discomfort in otherwise healthy children. Children who are infected first show signs of general malaise, which is followed shortly by the appearance of a lacy red rash on the face. The rash soon spreads all over the body, and affected children may run a slight fever and experience itching. This virus is contagious only before the rash appears, so it is unnecessary to isolate children who have the rash.
Usually seen in children 4 years of age or younger, roseola infantum is caused by the Herpesvirus-6, according to the Continuity Clinic Notebook. The infection's onset is characterized by a high fever, which may pose a threat of febrile seizures in some infants, followed shortly by a rash that first appears on the trunk and then spreads to the child's extremities. Fever management with acetaminophen is the recommended course of treatment. This is not a contagious condition, so affected children need not be isolated.
The two most common enteroviral illnesses---hand-foot-and-mouth disease and herpangina---are caused by coxsackieviruses. Neither is particularly threatening to a child's health, and both are accompanied by fever, which can best be treated with acetaminophen. The former illness is characterized by fever and a rash that may include blisters in the mouth and on the tongue, as well as on the hands and feet. Herpangina patients also will run a fever, usually accompanied by a sore throat and painful blisters or ulcers at the back of the mouth.