Fifth Disease

Fifth disease is a mild illness caused by a virus called human parvovirus B19. The medical name for fifth disease is erythema infectiosum (EI).

This infection occurs primarily during winter and spring, most commonly in children between 5-14 years of age. Initially, fifth disease causes an erythematous (reddish) rash on the child's face appearing as though the child had been slapped on both cheeks.

Sometimes in North America, the disease has been referred to as "slapped cheek syndrome" or simply "slapcheek." The characteristic appearance of the rash gave rise to the names "apple sickness" (or ringo-byou) in Japan and "butterfly pox" in Hungary (since the cheeks resemble the wings of a butterfly).

• The virus is thought to spread via droplets in the air (respiratory secretions transmitted by coughs and sneezes) or by blood from other infected people. Early during the illness, nasal secretions contain the viral DNA. Blood has been found to contain viral particles as well as DNA. The virus is capable of crossing the placenta and affecting the fetus if a pregnant women becomes infected.
• Cases of fifth disease can occur either sporadically or as part of community outbreaks. Outbreaks occur mainly in elementary schools during the spring. Half of the cases occur from the spread of the virus to others in the patient's household. Transmission of the infection in schools is less common.
• At least half of North-American adults have been infected by parvovirus B19 and are unlikely to be reinfected. About 10% or fewer young children are immune.
• People with this illness are contagious before the onset of symptoms and are probably not contagious after they develop the rash. The incubation period (the time from acquiring the infection to the development of symptoms) usually lasts between four and 21 days.
• The name fifth disease comes from a classification system developed in the 1890s that is no longer used. It was the fifth in a list of the five most common rashes (or exanthems) of childhood and therefore acquired this name. Other childhood exanthems included measles (first), scarlet fever (second), German measles (third), etc.
• After recovery from fifth disease, lifelong immunity is generally guaranteed.

Infection with human parvovirus B19 was identified as the cause of fifth disease in 1975, although Robert Willan first reported the rash in 1799 as "rubeola, sine catarrho" (rubeola, measles without cough).

The doctor can make a diagnosis by taking a medical history and performing a physical exam. The classic rash is often the key. Blood testing or other specialized tests are usually not required.

Risk factors for developing fifth disease center around the winter and spring seasons and frequenting areas of high contagiousness (for example, preschool and early elementary school). Since the most contagious time period is when the child has no overt symptoms, exposure to a healthy child is a common experience.

While fifth disease is more common in children, adults can be affected by it as well. Those with fifth disease who are immune-compromised are potentially more at risk for the development of complications than their peers with intact immune systems. Pregnant women who develop fifth disease may potentially develop problems with the fetus and should discuss their individual case with their obstetrician.

Pregnant women who develop fifth disease may potentially develop problems with the fetus and should discuss their individual case with their obstetrician. If you are pregnant and believe you have fifth disease or were exposed to it, you should call your doctor right away for further medical advice.

Fifth disease is a mild, self-limited childhood illness that resolves without specific treatment. The symptoms may, however, resemble those of other illnesses. If you have any doubt, contact your doctor for a diagnosis.

Pediatricians and family practice physicians are generally the primary doctors who treat patients with fifth disease.

• Fifth disease usually starts as a mild vague illness and nonspecific symptoms. Low-grade fever occurs 15%-30% of the time, along with nasal congestion and drainage, mild sore throat, fatigue, muscle aches, and a headache. This lasts for several days.
• Then, seven to 10 days later, the characteristic facial rash (slapped cheeks appearance) develops abruptly. Typically, the facial rash is bright red. The child looks as if a hand has been slapped across his or her face. This rash fades within approximately four days.
• As the slapped cheek skin changes fade, a light pink rash begins on the arms and then may spread to the trunk, buttocks, and thighs. This gradually fades to a lacy pattern lasting three to four days and then clears.

For most healthy children, supportive care for symptoms at home (such as fever and mild aches) is all that is needed. Children should limit their activities until they feel better.

Home care is geared toward relieving symptoms.

• Drink plenty of fluids.
• Take acetaminophen (Tylenol, for example) to control the fever. Avoid aspirin due to the risk of developing Reye's syndrome in a child with a fever.
• Wash your hands, and take care not to spread the virus.

To decrease the risk of transmitting the virus, anyone with fifth disease, as well as those around the infected person, must practice regular hand washing and throw away tissues containing nasal secretions.

By the time fifth disease is recognized, the period of greatest risk for spreading the illness has already passed. Therefore, parents must use caution and good judgment about when to send children back to school or daycare.

Routine exclusion of pregnant women from the workplace where this illness is occurring is not recommended. Pregnant women with significant exposure should see their doctor for counseling, possible testing, and reassurance.

Fifth disease produces mild symptoms that go away on their own. Complications may occur in people who have weakened immune systems (such as those infected with HIV, undergoing chemotherapy for cancer, or taking immunosuppressive drugs).

Complications are rare but may also occur to the unborn fetus in pregnant women. Women infected with parvovirus B19 can miscarry when the fetus becomes significantly swollen (a condition called hydrops fetalis).