What is Fifth Disease?
Fifth disease (aka erythema infectiosum) is a viral rash that is common in childhood. We see it most in children aged 4-13 years. The rash is caused by the Parvovirus B19 (unrelated to parvovirus found in dogs) and received its name when it was the fifth discovered childhood disease causing a rash. Other childhood illnesses causing rashes include measles, chicken pox (varicella), scarlet fever, and roseola; thankfully fifth disease, is a much milder illness than the others listed.
Signs and Symptoms
Fifth disease begins with mild cold-like symptoms with or without a low-grade fever (not over 102°F). After the fever resolves, the child will develop bright red cheeks, having the appearance of “slapped cheeks.” This will last 1-3 days and is then followed by a lacy or “net-like” rash to the upper arms and legs. In approximately 50% of children, the rash will also appear on the stomach. The rash is typically not itchy and causes no discomfort.
How is the diagnosis made?
The diagnosis is easy for your provider to make through the history and visualization of the rash.
Thankfully, no treatment is needed, and the rash will resolve on its own without causing the child any discomfort. The rash on the arms and legs may come and go for 1-3 weeks and will appear more pronounced in the sunlight and when skin is warm (after baths or showers). This does not mean your child needs to avoid these activities.
Prevention and return to school
Once the rash is present, the child can no longer spread the virus to others and the rash is not a reason to stay out of school. The child was contagious 1 week before the rash occurred. For this reason, fifth disease spreads quickly through childcare settings and schools since children are often relatively well appearing, while they are most contagious, the week before the rash occurs. If you think your child was exposed to fifth disease but is not yet exhibiting the rash, good hand washing can help prevent the spread to others.
Other useful information
Though fifth disease is harmless to children, it can he harmful to an unborn baby. If a child with fifth disease was in close contact with a pregnant woman, it is important for her to contact her OB/Gyn provider. Typically, the OB/Gyn will perform a test to determine if the pregnant woman has herself previously had fifth disease, and if so, she is protected.
ClearTriage. Copyright 2000-2019 Schmitt Pediatric Guidelines LLC. Author: Barton Schmitt MD, FAAP