Which among the following is true regarding Exathem
Ans) c (forreschmier spot is pelecliial....)RefNelson 18th ed pl339, 1317, 1357Human herpesvirus 6 (HHV-6) is a dominant cause of roseola infantum which is also known as exan them subitum or sixth disease. Parvovirus B19 is the cause of erythema infectiosum or "fifth disease,"Rubella or German measles or 3-day measles is a mild, often exanthematous disease of infants and children that is typically more se-vere and associated with more complications in adults.About the time of onset of the rash, examination of the throat may reveal tiny, rose-colored lesions (Forchheimer spots) or petechial hem-orrhages on the soft palate.Koplik spots, is the pathognomonic sign of measles and appeals 1 to 4 days prior to the onset of the rash. They first appeal' as discrete red lesions with bluish white spots in the center on the inner aspects of the cheeks at the level of the premolars.They may spread to involve the lips, hard palate, and gingiva. They also may occur in conjunctival folds and in the vaginal mucosa. Koplik spots have been reported in 50-70% of measles cases but probably occur in the great majority. Varicella in Vaccinated Individuals or "Breakthrough Varicella"Vaccine is >95% effective in preventing severe varicella and is most commonly about 80% effective at preventing all disease after expo-sure to wild-type VZV. This means that following close exposure to VZV, as may occur in a household or an outbreak setting in a school or daycare center, 1 of every 5 vaccinated children may develop breakthrough vari-cella. Exposure to VZV may also result in asymptomatic infection in the previously immunized child.In contrast, breakthrough disease is varicella that occurs in a per-son vaccinated >42 days before rash onset and is caused by wild-type VZV.The rash in breakthrough disease is frequently atypical, predomi-nantly maculopapular, vesicles are seen less commonly, and the illness is most commonly mild with <50 lesions and little or no fever. Breakthrough cases are less contagious than wild-type infections within household settings.Children with breakthrough disease should be considered poten-tially infectious and excluded from school until lesions have crusted or, if there are no vesicles present, until no new lesions are occurring. Trans-mission has been documented to occurfrom breakthrough cases in house-hold, child-care, and school settings.
Roseola infantum is fifth disease
Koplick spot cannot occur before rash
Forreschmier spot is petechial spot in soft palate in rubella
Symptoms of vaccine (Breakthrough) chickenpox is similar to unvaccinated type
Infection