Fifth Disease

Alternate Names
erythema infectiosum

Definition of Fifth Disease

Fifth disease (so named because it was fifth on a list of common illnesses that caused rashes many decades ago) is a viral infection caused by parvovirus B19. It usually causes a rash and mild illness with low grade fever.

What is going on in the body?

Fifth disease is caused by human parvovirus B19. It most often occurs in the spring in children and adolescents. Fifth disease is spread through respiratory secretions. Symptoms appear 4 to 14 days after exposure.

What are the signs and symptoms of the infection?

Fifth disease in children often follows a typical pattern. While rash is the most striking symptom of fifth disease, the child may have the following symptoms several days before the rash appears:

• cold symptoms, including a cough and runny nose
• malaise, or a vague feeling of illness
• slight fever

A child with fifth disease generally has a bright-red rash on the cheeks that gives a "slapped cheek" appearance. This may be followed by a pink, lacy rash on the arms, legs, and trunk. The rash generally causes no discomfort but may be mildly itchy.

An adult with fifth disease may have no symptoms at all or may have the typical rash. The person may also have joint pain and swelling.

What are the causes and risks of the infection?

Fifth disease is generally seen in children in day care, preschool, elementary school, and high school. Adults who are not immune to the parvovirus B19 can also develop fifth disease. It is spread from person to person by respiratory secretions. Coughing and sneezing spread the infection.

What can be done to prevent the infection?

Fifth disease is a very contagious viral disease. There is no vaccine or other way to prevent it. General precautions include washing the hands thoroughly and avoiding the respiratory secretions of others.

How is the infection diagnosed?

The diagnosis of fifth disease is made on the basis of a medical history and physical examination. When an exact diagnosis is important, the healthcare professional can order an antibody titer blood test.

What are the long-term effects of the infection?

There are few long-term effects in most otherwise normal individuals affected with fifth disease. It is a benign viral infection from which complete recovery is expected.

However, people with anemia or immune system disorders are at risk for an episode of acute, severe anemia if they have fifth disease.

If fifth disease is passed from a pregnant woman to her unborn child, the baby may develop severe anemia (a shortage of red blood cells) and widespread swelling. This condition, known as hydrops fetalis, can cause stillbirth.

What are the risks to others?

Fifth disease is passed from person to person by respiratory secretions spread by coughing, sneezing, or intimate contact.

The disease is mild enough that precautions to prevent spread, such as are taken for measles or even chickenpox, are not generally considered worth taking. The exception is for a pregnant woman, who should avoid exposure to a person with fifth disease if possible.

Many times, however (the classic case is a pregnant schoolteacher) the exposure has already happened before it is recognized. In such a case, the woman's healthcare professional should be informed of the exposure, but fortunately almost every time the baby is born entirely normal.

What are the treatments for the infection?

Fifth disease usually resolves on its own without treatment.

Fever or joint pain may be relieved with over-the-counter pain medications such as acetaminophen (i.e., Tylenol). Aspirin should never be given to children without a healthcare professional's order (and certainly not for fifth disease), since it increases the risk of Reye's syndrome. Cool baths or compresses may help relieve itching from the rash.

What are the side effects of the treatments?

Medications used to relieve pain or fever may cause stomach upset or allergic reactions.

What happens after treatment for the infection?

The rash associated with fifth disease usually fades in one to two weeks. However, the rash may reappear following exposure to sunlight, heat, exercise, or stress. This does not mean that the illness has returned.

How is the infection monitored?

Any new or worsening symptoms should be reported to the healthcare professional.