Fifth Disease(Erythema Infectiosum)
Fifth disease or Erythema Infectiosum is caused by a virus called Parvovirus B19. Fifth disease is most common in children between 5 and 15 years old and begins with a low-grade fever, headache, and mild cold-like symptoms. A few days later, a bright red rash develops on the face giving a "slapped-cheek" appearance. The "net-like or lacy" rash then spreads to the trunk, arms, and legs. It may take up to 3 weeks for the rash to completely clear. In the meantime, exposure to sunlight, heat, exercise, and stress may worsen the rash. Rarely, mostly in older kids and adults, the Parvovirus infection may cause hand, wrist, knee and ankle joint swelling or pain.
Is Fifth Disease Serious?
The vast majority of people who develop Fifth disease get over the infection without any consequences or complications. However, children with weakened immune systems (i.e. AIDS) or certain blood disorders (i.e. sickle cell anemia) may become quite ill. Also, Parvovirus B19 infection during pregnancy may cause problems for the unborn child, especially if the infection occurs during the first half of the pregnancy. Fortunately, about 50% all pregnant women are immune or protected from having had a previous infection with Parvovirus. Serious problems occur in less than 5% of women who become infected during pregnancy. Female teachers and child care givers of child bearing age, should be aware of this potential complication. Pregnant women who develop a rash or have been exposed to someone with Fifth disease should call their obstetrician.
Making the Diagnosis
Making the diagnosis of Fifth disease is usually made upon recognising the characteristic rash a child develops. Specific blood tests are also available to determine if a child is infected by the Parvovirus. These same tests are used to determine if someone has had a parvovirus infection in the past. This would be important if we wanted to determine whether a pregnant woman, for example, in contact with Fifth disease is immune or not. If the blood test shows that she has had Parvovirus infection in the past then she is protected.
There are no available anti-viral medications that will treat Fifth disease nor can it be treated with antibiotics. Usually, children with Fifth disease feel fairly well and need little treatment other than rest. Acetaminophen (Tylenol or Tempra) may be recommended for fever or joint pain. At this time, there is no vaccine for Fifth disease.
When is Fifth Disease contagious?
A child with Fifth disease is most contagious a few days before the rash appears. Note that a child is usually not contagious once the rash appears. Isolating a child with a Fifth disease rash will not prevent spread of the infection because the child usually is not contagious by that time.