- Caused by human parvovirus B19.
- Most common in young children (3-15 years). About 60 per cent of adults are seropositive.
- Tends to occur in late winter and early spring.
- Incubation period 4-14 days.
- Mild prodromal headache, low grade fever, coryza. Patient may be unaware of these.
- Onset of red cheeks; fades within 2-4 days. Nose, perioral and periorbital regions spared.
- Followed by lacy, morbilliform rash, mainly on the limbs.
- Rash may fade and recur over the following three weeks.
- Adults, particularly women, may develop a polyarthropathy that may persist for months.
- Complications in children are rare, but are more of a problem in adults, especially in pregnancy; for example, intrauterine death, hydrops fetalis, anaemias.
Red cheeks mark disease onset
- Children - symptomatic treatment only while awaiting spontaneous resolution.
- If diagnosis is doubtful or during pregnancy confirmation of the diagnosis will be important.
- Pregnancy - refer women after exposure to the virus or with IgM antibodies to PV-B19 to obstetrician for assessment of possible complications.
- Rash caused by release of erythrogenic toxin from group A ss-haemolytic streptococcus.
- Transmitted in respiratory droplets.
- More common in children aged 4-8.
- Most have acquired lifelong antibody protection by the age of 10.
- Infants under the age of two are protected by maternal antibodies.
- Incubation period 1-4 days.
- School exclusion for 24 hours after initiation of antibiotics or until well enough.
- Scarlet fever is a notifiable disease.
- Sudden onset of fever, sore throat, headache and vomiting.
- Erythematous rash with scarlet macules develops within 12-48 hours.
- Rash spreads from face to the trunk and limbs.
- Strawberry tongue - white-coated tongue with red papillae showing through.
- After 4-5 days, raspberry tongue as white coating clears.
- Rash fades after about a week and is followed by desquamation.
The rash fades after a week
- Rheumatic fever, peritonsillar abscess, pneumonia, meningitis.
- Antibiotics treatment reduces the risk of complications.
- Throat swab to confirm group A ss-haemolytic streptococcus.
- Antistreptolysin O test after the acute phase will confirm the diagnosis if the titre is high.
- Drug of choice is phenoxymethylpenicillin V for 10 days.
- Alternatives are erythromycin or a cephalosporin.
Contributed by Dr Jean Watkins, a sessional GP in Hampshire.