Randy Jacobs, M.D. Patient Education

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Exanthems - Roseola



Exanthems are a common cause of generalized rashes in children. They pose a diagnostic challenge to even the most experienced physician because of the diversity of their clinical presentations. The morphology distribution, and associated signs and symptoms are sometimes specific enough for a definitive diagnosis, but, nonspecific clinical findings often make this impossible. Advances in laboratory techniques (particularly in viral diseases), new antiviral drugs and vaccines, epidemics of old exanthems, and the recognition of new clinical syndromes have stimulated renewed interest in exanthems. Historically, exanthems were numbered in the order in which they were first differentiated from other exanthems. Thus, "first" disease was measles (rubeola), "second" disease was scarlet fever, and "third" disease was rubella (German measles). The specific disease described as "fourth" disease, so-called Pilatov-Dukes disease, is no longer accepted as a distinct clinical entity, with some authors speculating that it represented staphylococcal scalded skin syndrome, and others speculating that it was concurrent infection with both scarlet fever and rubella. Fifth disease is erythema infectiosum, and sixth disease is roseola infantum. Only in the last decade, with the identification of parvovirus B19 as the cause of erythema infectiosum and human herpesvirus 6 as the cause of roseola infantum, have the causative agents of the classic exanthems been identified.

Roseola Infantum


Sixth Disease, also known as "roseola infantum" is an acute infectious disorder of infants or very young children. Characterized by high fever and the appearance of a red skin rash, this disorder may resemble rubella after the fever has disappeared. Seizures may also occur.



The incubation period before symptoms of roseola infantum appear is approximately 5 to 15 days. A high fever begins abruptly and usually lasts for 3 or 4 days without an obvious identifiable cause. Convulsions are common during this period. Low levels of white blood cells (leukopenia) may occur by the 3rd day. The spleen may be slightly enlarged. The fever usually breaks on the 4th day, and a characteristic rash of red spots or elevated (macular or maculopapular) spots appears. This rash may cover the chest and abdomen, although it often appears in a mild form on the face and extremities. Temperature returns to normal at this stage, and the child usually feels and acts well. In some cases, the rash may be so mild that it goes unnoticed.



Cause: Roseola infantum is caused by a viral infection related to the herpes group of viruses. Affected population: Roseola infantum usually affects children between 1 and 3 years of age. The disorder tends to occur most often in the spring and fall seasons. Minor epidemics in certain geographic areas have been reported.


Similar Disorders

Symptoms of the following disorders can be similar to those of roseola infantum. Comparisons may be useful for a differential diagnosis: Atypical Measles Syndrome (AMS) is most common among adolescents and young adults. This disorder was usually associated with prior immunization using the outdated killed measles vaccines, which are no longer in use. However, inoculation with live measles vaccine has also been known to precede development of AMS. Presumably, inactivated measles virus vaccines do not prevent mild virus infection and can sensitize patients so that disease expression is altered significantly. AMS may begin abruptly, with high fever, headache, abdominal pain, and coughing. The rash may appear one to two days after onset, often beginning on the extremities. Swelling (edema) of the hands and feet may occur. Pneumonia is not uncommon, and nodular dense areas in the lungs may persist for three months or longer. Measles (Rubeola or Morbilli) is a highly contagious viral disease occurring primarily in children. The disease is characterized by fever, cough, acute nasal membrane discharge (coryza), inflammation of the lining of the eyelids (conjunctivitis), and eruption of small, irregular, bright red spots with a minute bluish or white speck in the center (Koplik's spots) on the inner cheeks or lips and a rash of elevated spots (maculopapular) spreading over the skin. Measles has become rare in the United States since the introduction of measles vaccines. Rubella (German Measles) in children is a mild contagious viral disease characterized by swelling of Iymph glands and a rash beginning on the face and neck which quickly spreads to the trunk and the extremities. If a woman contacts rubella during the early months of pregnancy, a spontaneous abortion, stillbirth, or birth defects in the infant may result. Scarlet Fever is an infection caused by bacteria that usually affects the mouth and throat area (pharynx), but may also affect the skin or birth canal. Patients may experience headache, abdominal pain, nausea, and a skin rash. A reddish flush may be apparent on the face, chest and extremities, accompanied by tiny red spots in some cases. The disease is much milder now than in the past, and complications are rare with proper treatment.


Standard Therapies

Once a person is infected with roseola infantum, there is little to do other than let the disorder run its course, and make the patient as comfortable as possible. Medication to bring down the fever may be helpful in serious cases. However, the use of aspirin to treat viral diseases in children and young adults should be avoided because of the risk of Reye Syndrome, a rare but life-threatening condition.