Exanthem Subitum (Roseola Infantum)

Exanthem subitum (sixth disease/roseola) is an acute exanthematous childhood infection caused by HHV-6/7. Clinical: high fever 3-4 days then abrupt defervescence with rash; rash fades in hours, gone in 2-3 days, no desquamation/pigmentation. Good prognosis, self-resolving.

Common Symptoms

Anorexia; convulsion; papulomacular rash; chronic pharyngeal injection

Causes and Pathogenesis

(1) Etiology: HHV-6 (main); HHV-7 also. HHV-6 isolated 1986 by Salahuddin from lymphoproliferative patients; β-herpesvirus, 66% homologous to CMV; named 1987. Isolated from ES PMNs/CD4/CD8/monocytes in 1988; most ES by HHV-6B. 90-110 nm icosahedral 162-capsomere virion, 180-200 nm mature. HHV-7 (Frenkel 1990) from healthy adult T cells, ~200 nm, β-herpesvirus. (2) Pathogenesis: lymphotropic. HHV-6 genome 163-170 kb, encodes 70+ proteins (IE-A/IE-B); variants A/B (75-99% homology); latency in PBMCs/salivary gland/kidney/bronchial; reactivation by HIV/EBV/measles/CMV. HHV-7 also T-lymphotropic, present in healthy saliva.

Treatment

Drug therapy, rehabilitation

Preventive Measures

Isolate child until 5 days after rash; low contagiousness; avoid public places during outbreaks.

Department to Visit

It is recommended to visit the General Pediatrics department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.