1. After an incubation period of 4 to 21 days, the classic symptoms of malaise, fever, and red “slapped” cheeks appear, signaling that the child is no longer infectious. Four to 14 days after the onset of symptoms, a pruritic lacy rash covers the entire body, preferentially on the extensor surfaces.1,2
Photo courtesy of Richard P. Usatine, MD and the Color Atlas of Family Medicine. 2nd ed.
Diagnosis: Fifth disease, also known as slapped cheek syndrome or erythema infectiosum, is caused by parvovirus B19, an infectious agent found worldwide. It is transmitted via respiratory droplets, most commonly in late winter and early spring. The peak incidence of parvovirus B19 infection is in children ages 5 to 15 years.1 Approximately 20% of parvovirus B19 infections remain subclinical.1,3 An observational study of children in the United Kingdom who were 6 months to 16 years of age and had been immunized for measles and rubella revealed that parvovirus B19 was the number one identifiable cause of febrile rash, responsible for 17% of cases.4 Seroprevalence increases with age, and 40% to 60% of adults test positive for prior infection.1
1. Kliegman RM, Stanton BMD, St. Geme J, et al. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Elsevier/Saunders; 2011.
2. Anderson LJ. Role of parvovirus B19 in human disease. Pediatr Infect Dis J. 1987;6:711-718.
3. Tuckerman JG, Brown T, Cohen BJ. Erythema infectiosum in a village primary school: clinical and virological studies. J R Coll Gen Pract. 1986;36:267-270.
4. Ramsay M, Reacher M, O’Flynn C, et al. Causes of morbilliform rash in a highly immunised English population. Arch Dis Child. 2002;87:202-206.
For more information, see “Fifth and sixth diseases: More than a fever and a rash.” J Fam Pract. 2014 October;63(10):E1-E5.