Fifth Disease

Definition

Fifth disease is a viral disease, caused by parvovirus 19, that takes its name from being the fifth of six pediatric disorders identified by scientists.

The first four were rubella, measles, scarlet fever and Dukes disease, which is a mild form of scarlet fever. The sixth disorder is exanthema subitum, also called roseola infantum.

Description

Fifth disease is an acute, benign infectious disease, mainly of children, characterized by fever and an erythematous rash beginning on the cheeks and appearing later on the arms, thighs, buttocks and trunk. As the rash progresses, earlier lesions fade. Sunlight aggravates the eruption, which usually lasts about 10 days.

For a period of time the rash may reappear whenever the skin is irritated. Its cause is unknown, no treatment is necessary, and prognosis is excellent. It is also known as erythema infectiosum.

Most cases of fifth disease occur in children 5 to 14 years old, and outbreaks are more common during winter and spring. Once infected, a person has lifetime immunity. For adults who passed through childhood without catching fifth disease, symptoms can be more severe, including arthritis and arthralgias (joint pains).

Fifth Disease and Pregnancy

Fifth disease in pregnancy does not appear to cause birth defects. It can, however, disrupt the fetus' ability to produce red blood cells. Sometimes this leads to a dangerous form of anemia, heart failure, abnormal pooling of fluid (referred to as fetal hydrops), and fetal death. The result can, in a minority of cases, be miscarriage or stillbirth.

Fortunately, fewer than one-third of pregnant women's infections result in their fetus's becoming infected. And most infected fetuses quickly resume red blood cell production and avoid anemia. These babies are born healthy, with no apparent problems resulting from infection.

According to the American Academy of Pediatrics, the risk of fetal infection appears to be highest when a pregnant woman is infected during the first 20 weeks of pregnancy. Studies suggest, however, that only three to nine percent of cases of maternal infection in the first 20 weeks result in fetal death.

If a person is exposed to fifth disease during pregnancy, a doctor should be consulted promptly. The doctor may suggest a blood test to determine whether the patient has had fifth disease in the past - and is presumably immune - or whether she has been mildly infected.

In a few cases, severely affected fetuses have been successfully treated with intrauterine blood transfusions and this treatment may prove lifesaving for babies with hydrops caused by fifth disease.

Causes and Risk Factors

Fifth disease is caused by infection with parvovirus 19, a common virus.

Symptoms

Usually, the first symptoms are low-grade fever and a feeling of malaise. Then, anywhere from seven to 10 days later, the rash will appear. In many children, the symptoms are mild, and in approximately 20 percent of those infected, there are no symptoms at all.

If anything about fifth disease can make a lasting impression, it is the distinctive "slapped cheek" appearance of the facial rash. The rash then spreads to the trunk and extremities, frequently developing a lacy pattern. The rash generally fades within two weeks, but external factors such as sun exposure, bathing, excitement, or exercise can cause it to reappear several weeks later.

Treatment

There is no treatment. If the rash persists, plain calamine lotion and cool water should provide relief.

Questions to Ask Your Doctor

Does the diagnosis clearly establish the existence of fifth disease?

Is this matter of concern?

What can be done to alleviate the symptoms?

(If pregnant) Can fifth disease lead to fetal damage or even fetal death?

(If pregnant) Should a blood test be done to determine whether immunity exists?

(If pregnant) Can you determine whether the fetus has developed complications?

(If pregnant) What can be done to protect the fetus?