A variety of viral infections can cause rashes in conjunction with fevers. These conditions, known as viral exanthems, usually present with fever and a variety of other symptoms. Many of the more dangerous infections can be prevented with good prenatal care and by adherence to vaccination regimes practiced in the United States. If an infant has a rash, fever and other abnormal symptoms, parents should bring their child to a doctor for evaluation and laboratory testing.
Roseola
Roseola infantum, or exanthema subitum, is a viral disease that commonly presents between 6 and 15 months. The disease is caused by human herpesviruses 6 and 7. Like other viral fevers, it probably is spread through salivary and nasal secretions. The classic finding in roseola is a sudden high fever. The fever persists for three to five days. This is followed by resolution of the fever and the formation of the rash. The rash starts on the trunk, then spreads to the extremities.
Neonatal Herpes
Neonatal herpes is becoming more common. The disease spreads to the baby by an infected mother with an active outbreak. The herpes virus can spread quickly through the entire body of the infant. The skin disease occurs from the fifth to 11th days of life and causes the formation of small blisters, called vesicles, in the skin and mouth. These may burst to form shallow ulcers. A more severe disease affecting the internal organs, including the brain, can occur after several days. These infants should be treated promptly with antiviral drugs.
Varicella
Varicella, or chicken pox, in infants is much more severe than it is in older children. Infants whose mothers develop chicken pox from five days prior to two days after delivery are at a particularly high risk. The rash occurs at about the first week of life. Complications of varicella in infants are pneumonia, hepatitis and a brain infection, known as encephalitis. Infants should be treated promptly with the antiviral agent acyclovir.
Measles
Measles, sometimes confusingly called "rubeola," also can cause a rash in infants. Like most other viral infections in this age group, the disease is spread by droplets from the nose, mouth and throat. Before the rash, the infected child may have a runny nose, watery eyes, sneezing and a fever. The rash itself starts from the forehead and slowly works its way down to the rest of the face, trunk and limbs; eventually it may reach the palms and soles. It lasts for about seven days and disappears in the same pattern. Complications of measles include pneumonia, diarrhea and encephalitis.
Rubella
Rubella, also called "three-day measles" or "German measles," is a benign viral fever. Like measles, it is spread by oral and nasal secretions. Symptoms include fever, sore throat, red eyes, headache and swollen lymph glands. The rash that forms in rubella is not very distinctive. It starts on the torso and spreads to the extremities.
Both measles and rubella are prevented by the MMR vaccination, given between 12 and 15 months. Though rubella infection is benign, its infection in pregnant women can cause a severe disease in newborns.
Nonspecific Febrile Illness
Many of febrile rashes in infants are due to a variety of other viruses. These include different varieties of coxsackie viruses, enteroviruses and echoviruses. These conditions are broadly classified as "nonspecific febrile illnesses." Symptoms include fever, diarrhea, sore throat, abdominal pain and a rash. The fevers usually last three days and laboratory tests generally are normal. Doctors may have difficulty differentiating these otherwise harmless conditions from more serious bacterial infections.
References
- "Nelson Textbook of Pediatrics"; Dr. Robert M. Kliegman, et al.; 2008
- University of Chicago: Pediatric Exanthems
