From the Research
Fifth disease, also known as erythema infectiosum, is typically confirmed through clinical evaluation of the characteristic "slapped cheek" rash and other symptoms, though laboratory testing can provide definitive diagnosis when needed. A healthcare provider will first assess symptoms including the distinctive bright red rash on the cheeks, followed by a lacy red rash on the trunk and limbs that may come and go for several weeks 1. The diagnosis is mainly clinical, and physicians should be well-versed in the clinical manifestations of erythema infectiosum to avoid misdiagnosis, unnecessary investigations, and mismanagement of the disease.
Some key points to consider in the diagnosis of fifth disease include:
- The characteristic "slapped cheek" appearance on the face
- A lacy or reticulated exanthem on the trunk and extremities
- The rash tends to be more intense on extensor surfaces
- The palms and soles are typically spared
- Pruritus is noted in approximately 50% of cases
Blood tests can detect antibodies to parvovirus B19 (the virus that causes fifth disease) or directly detect viral DNA through PCR testing 1. These tests are particularly useful in pregnant women, immunocompromised patients, or when the diagnosis is unclear. No specific treatment is required for fifth disease as it typically resolves on its own within 1-3 weeks. Symptomatic relief may include acetaminophen or ibuprofen for fever and discomfort, adequate hydration, and rest. The disease is most contagious before the rash appears, so by the time the characteristic rash develops, the person is usually no longer contagious. Special consideration should be given to pregnant women and people with certain blood disorders or compromised immune systems who may need closer monitoring if exposed to or infected with parvovirus B19.