Roseola overview
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Omodamola Aje B.Sc, M.D. [2]
Overview
Roseola is a disease of infants. It is characterized by an abrupt rise in body temperature to as high as 40°C (104°F) followed by a rapid drop to normal within the next 2–4 days which coincides with the appearance of an erythematous maculopapular skin rash that persists for 1–3 days. It is typically a beningn disease which resolves without sequalae. Roseola disease is caused by Human herpes virus 6 (HHV6). HHV-6 is a member of the Herpesvirales order, Herpesviridae family, Betaherpesvirinae subfamily, and Roseolovirus genus. HHV-6A and HHV-6B are two distinct species of HHV-6.
Historical perspective
Human herpes virus 6 was first identified in 1986. Herpesviruses have a unique four-layered structure: a core containing the large, double-stranded DNA genome is enclosed by an icosapentahedral capsid which is composed of capsomers. The capsid is surrounded by an amorphous protein coat called the tegument. It is encased in a glycoprotein-bearing lipid bilayer envelope.
Classification
There is no established classification system for roseola.
Pathophysiology
Primary infection with HHV-6 has been shown to be the cause of exanthem subitum (roseola) in infants and can also result in an infectious mononucleosis-like illness in adults.
Causes
Roseola is caused by Human herpes virus 6, a member of the Herpesvirales order, Herpesviridae family, Betaherpesvirinae subfamily, and Roseolovirus genus. Herpesviruses have a unique four-layered structure: a core containing the large, double-stranded DNA genome is enclosed by an icosapentahedral capsid which is composed of capsomers. The capsid is surrounded by an amorphous protein coat called the tegument. It is encased in a glycoprotein-bearing lipid bilayer envelope.
Differential diagnosis
Roseola must be differentiated from other diseases that cause fever and rash, such as Rubella (german measles), Rubeola (measles), hand foot and mouth disease caused by coxakie virus, erythema infectiosum caused by parvovirus B19, scarlet fever and even drug allergy.
Epidemiology and demographics
Roseola is an illness of young children, with a peak prevalence between 7 and 13 months. Ninety percent of cases occur in children younger than two years. Roseola occurs equally in boys and girls. It occurs throughout the year, although outbreaks may occur in groups according to season .
Risk factors
The common risk factor in the development of roseola is infancy: 6 - 15 months.
Screening
According to the USPSTF, there is insufficient evidence to recommend routine screening for roseola.