|Classification and external resources|
Electron micrograph of HHV-6
|eMedicine||emerg/400 derm/378 ped/998|
Exanthema subitum (meaning sudden rash), also referred to as roseola infantum (or rose rash of infants), sixth disease (as the sixth rash-causing childhood disease), and (confusingly) baby measles, or three-day fever, is a disease of children, generally under two years old, although it has been known to occur in eighteen-year-olds, whose manifestations are usually limited to a transient rash ("exanthem") that occurs following a fever of about three day's duration.
It is caused by two human herpesviruses, HHV-6 (Human herpesvirus 6) and HHV-7, which are sometimes referred to collectively as Roseolovirus. There are two variants of HHV-6 (HHV-6a and HHV-6b) and studies in the US, Europe, Dubai and Japan have shown that exanthema subitum is caused by HHV-6b. This form of HHV-6 infects over 90% of infants by age 2. Research has shown that babies can be congenitally infected with HHV-6 via vertical transmission. This has been shown to occur in 1% of births in the United States.
Clinical features 
Typically the disease affects a child between six months and two years of age, and begins with a sudden high fever (39–40 °C; 102.2-104 °F). This can cause, in rare cases, febrile convulsions (also known as febrile seizures or "fever fits") due to the sudden rise in body temperature, but in many cases the child appears normal. After a few days the fever subsides, and just as the child appears to be recovering, a red rash appears. This usually begins on the trunk, spreading to the legs and neck. The rash is not itchy and may last 1 to 2 days. In contrast, a child suffering from measles would usually appear more infirm, with symptoms of conjunctivitis, coryza, and a cough, and their rash would affect the face and last for several days. Liver dysfunction can occur in rare cases.
Vaccines and treatment 
There is no specific vaccine against or treatment for exanthema subitum, and most children with the disease are not seriously ill. A child with fever should be given plenty of fluids to drink. Paracetamol/acetaminophen or ibuprofen could be given to reduce their temperature (but never aspirin, due to the risk of Reye's Syndrome).
A small percent of children acquire HHV-6 "subclinically"; in other words, they show no outward sign of the disease. Exanthema subitum occurs in approximately 30% of children during primary HHV-6 infection. Others may be debilitated enough that a doctor's opinion is required to confirm the diagnosis, and particularly to rule out other more serious infections, such as meningitis or measles. In case of febrile seizures, medical advice is essential.
For HHV-6 infection, no pharmacological treatments have been approved as of June 2012. Although they may be unnecessary for exanthema subitum, the usage of Cytomegalovirus treatments (valganciclovir, ganciclovir, cidofovir, and foscarnet) have shown some success. These drugs are given with the intent of inhibiting proper DNA polymerization by competing with deoxy triphosphate nucleotides or specifically inactivating viral DNA polymerases.
Local terms 
|Country||Local name (language)||Translated name|
Zesde ziekte (Dutch)
|China (PRC)||急疹 (Mandarin) jí zhěn (pinyin)||"fast rash"|
|Czech republic||Šestá nemoc (Czech)||"sixth disease"|
|Finland||Vauvarokko (Finnish)||"baby measles"|
|Germany||Dreitagefieber (German)||"three-day fever"|
|Greece||Αιφνίδιο εξάνθημα (Greek)||"sudden rash"|
|Hungary||Háromnapos láz (Hungarian)
Hatodik betegség (Hungarian)
|Iceland||Mislingabróðir (Icelandic)||"measles' brother"|
|Italy||Sesta malattia (Italian)||"sixth disease"|
|Netherlands||Zesde ziekte (Dutch)||"sixth disease"|
|Norway||Fjerde barnesykdom (Norwegian)||"fourth disease"|
|Philippines||Tigdas Hangin (Tagalog)||"wind measles"|
|Poland||Trzydniowa goraczka (Polish)||"three-day fever"|
|Singapore/Malaysia||Jia3 Ma2 假麻 (Chinese)||"false measles"|
|Turkey||Altıncı hastalık (Turkish)||"sixth disease"|
|Israel||Adamdemet / אדמדמת (Hebrew)||"reddish disease"|
|Vietnam||Sốt phát ban (Vietnamese)||"baby rash"|
See also 
- Zerr DM, Meier AS, Selke SS, et al. (February 2005). "A population-based study of primary human herpesvirus 6 infection". N. Engl. J. Med. 352 (8): 768–76. doi:10.1056/NEJMoa042207. PMID 15728809.
- Universal childhood virus is inherited in DNA, newscientist.com
- Flamand, L.; Komaroff, A. L.; Arbuckle, J. H.; Medveczky, P. G.; Ablashi, D. V. (2010). "Review, part 1: Human herpesvirus-6-basic biology, diagnostic testing, and antiviral efficacy". Journal of Medical Virology 82 (9): 1560–1568. doi:10.1002/jmv.21839. PMID 20648610.
- Araujo, A.; Pagnier, A.; Frange, P.; Wroblewski, I.; Stasia, M. -J.; Morand, P.; Plantaz, D. (2011). "Syndrome d'activation lymphohistiocytaire associé à une infection à Burkholderia cepacia complex chez un nourrisson révélant une granulomatose septique et une intégration génomique du virus HHV-6". Archives de Pédiatrie 18 (4): 416–419. doi:10.1016/j.arcped.2011.01.006. PMID 21397473.
- Roseola – Topic Overview, webmd.com
- Stoeckle MY (2000). "The spectrum of human herpesvirus 6 infection: from roseola infantum to adult disease". Annu. Rev. Med. 51: 423–30. doi:10.1146/annurev.med.51.1.423. PMID 10774474.
- What is the role of aspirin?, reyessyndrome.org
- Zerr, D. M.; Meier, A. S.; Selke, S. S.; Frenkel, L. M.; Huang, M. L.; Wald, A.; Rhoads, M. P.; Nguy, L. et al. (2005). "A Population-Based Study of Primary Human Herpesvirus 6 Infection". New England Journal of Medicine 352 (8): 768–776. doi:10.1056/NEJMoa042207. PMID 15728809.
- Nakano, K.; Nishinaka, K.; Tanaka, T.; Ohshima, A.; Sugimoto, N.; Isegawa, Y. (2009). "Detection and identification of U69 gene mutations encoded by ganciclovir-resistant human herpesvirus 6 using denaturing high-performance liquid chromatography". Journal of Virological Methods 161 (2): 223–230. doi:10.1016/j.jviromet.2009.06.016. PMID 19559728.
- Jaworska, J.; Gravel, A.; Flamand, L. (2010). "Divergent susceptibilities of human herpesvirus 6 variants to type I interferons". Proceedings of the National Academy of Sciences 107 (18): 8369–8374. doi:10.1073/pnas.0909951107. PMC 2889514. PMID 20404187.
- Nylander, Gro (2009) "Lille venn, hva nå?"
- MedlinePlus encyclopedia entry on "roseola"
- Links to roseola pictures, Hardin MD/Univ of Iowa
- Newly Found Herpes Virus Is Called Major Cause of Illness in Young, New York Times
- HHV-6 Foundation
- DermNet viral/roseola