Fifth Disease

Fifth disease, also known as erythema infectiosum (air-uh-THEE-muh in-fek-she-0-sum), is a common viral infection of infants and young children that causes a characteristic "slapped cheek" rash.


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Erythema infectiosum


Slapped-cheek rash

Viral infections

What Is Fifth Disease?

Fifth disease, sometimes called slapped-cheek disease, is an infection caused by a virus called human parvovirus B19. Its most characteristic feature is a bright red rash that begins on the face, making the cheeks look as if they have been slapped. After a few days, the rash may spread down the body and onto the arms and legs. As it spreads, the rash takes on a pink, lacy appearance.

Most people with fifth disease have mild symptoms and do not become seriously ill; some may not have any symptoms at all. However, the disease can be serious for people with certain blood disorders, such as sickle-cell disease * , because parvovirus B19 can temporarily cause or worsen existing anemia * . For most people, temporary anemia is not a problem, but for those who already have anemia, the condition can become severe, causing paleness, fatigue, and a fast pulse. People with weakened immune systems, such as those who have AIDS * , cancer, or who have had an organ transplant, can also develop severe anemia as a result of fifth disease.

Parvoviruses can infect animals, but these are not the same strains * that affect humans. Therefore, a person cannot catch fifth disease from a dog or cat, and a pet cannot catch it from an infected person.

How Common Is Fifth Disease?

Fifth disease occurs most commonly in children between the ages of 5 and 15 years, but adults can get it too. It often occurs in outbreaks (for example, among classmates at school or children in a child-care center) in the winter and spring, but people can get it throughout the year.

Fifth disease spreads quickly. At home, up to half of family members exposed to someone with fifth disease will become infected. If an outbreak occurs in school, up to 60 percent of students may get the virus.

* sickle-cell disease is a hereditary condition in which the red blood cells, which are usually round, take on an abnormal crescent shape and have a decreased ability to carry oxygen throughout the body.

* anemia (uh-NEE-me-uh) is a blood condition in which there is a decreased amount of oxygen-carrying hemoglobin in the blood and, usually, fewer than normal numbers of red blood cells.

* AIDS, or acquired immunodeficiency (ih-myoo-no-dih-FIH-shen-see) syndrome, is an infection that severely weakens the immune system; it is caused by the human immunodeficiency virus (HIV).

* strains are various subtypes of organisms, such as viruses or bacteria.

A person with fifth disease can spread the infection in the early part of the illness, before the rash develops. By the time the rash appears (about a week after being exposed to the virus), a person likely is no longer contagious. Once someone is infected with parvovirus B19, that person develops immunity * to it and will not usually become infected again.

A few days after infection with the virus that causes fifth disease, the telltale "slapped cheek" rash appears on the face. Custom Medical Stock Photo, Inc.
A few days after infection with the virus that causes fifth disease, the telltale "slapped cheek" rash appears on the face.
Custom Medical Stock Photo, Inc.

Parvovirus B19 passes from one person to another through nose and mouth fluids, such as saliva and mucus. Any direct contact with the fluids of an infected person, whether through a cough or sneeze or by sharing drinking glasses or utensils, can spread the infection.

Fifth disease can also be passed from pregnant women to their unborn babies. Most of the time, the baby is not harmed. Occasionally the infection can cause severe anemia in the baby and lead to miscarriage * , especially if the baby was infected in the first half of pregnancy.

What Happens When People Get Fifth Disease?

Signs and symptoms

The first symptoms of fifth disease are similar to those of a common cold and include low fever, a runny or stuffy nose, sore throat, cough, headache, diarrhea, and fatigue. It is during this early period that fifth disease is most contagious. After a few days, especially in children, the slapped-cheek rash usually first appears on the face, and it soon begins to involve the rest of the body in a pink, lacy-looking pattern. Not everyone with fifth disease develops this rash; it is much more likely to appear in children under 10 years of age. For some people it will fade and reappear if triggered by heat, exercise, stress, or exposure to the sun. Sometimes the rash may itch, and adults in particular may experience pain and swelling of the joints in the hands, or the wrists, knees, or ankles.


In children, doctors can usually diagnose fifth disease simply by looking for the telltale rash on the face and body. In cases where there is no rash, blood tests can confirm the presence of parvovirus B19.

* immunity (ih-MYOON-uh-tee) is the condition of being protected against an infectious disease. Immunity often develops after a germ has entered the body. One type of immunity occurs when the body makes special protein molecules called antibodies to fight the disease-causing germ. The next time that germ enters the body, the antibodies quickly attack it, usually preventing the germ from causing disease.

* miscarriage is the ending of a pregnancy through the death of the embryo or fetus before birth.

Naming a Disease

Fifth disease was named in the late 1800s. It was the fifth classic childhood rash-associated disease to be named, following measles (first disease), scarlet fever (second disease), rubella or German measles (third disease), and a fourth condition with a rash that is unknown to doctors today (fourth disease). The name fifth disease probably stuck because it is a lot easier to say than erythema infectiosum.


Most people with fifth disease do not require treatment. Antibiotics will not help because the illness is caused by a virus. Symptoms such as fever or joint pain may be treated with acetaminophen (uh-see-teh-MIH-noh-fen), a medication commonly used to reduce fever and relieve pain.

The rash clears up on its own, often within 1 to 3 weeks. Joint pain and swelling can take longer to go away, sometimes up to several months. People with joint pain may need to rest and restrict their activities until they feel better.

People with blood disorders or immune deficiencies who develop severe anemia as a result of fifth disease may require blood transfusions * and other specialized medical care.


The vast majority of people who are infected with parvovirus B19 recover completely without any complications. Severe anemia, the complication most often associated with fifth disease, usually affects people with weakened immune systems or blood disorders and, rarely, unborn babies that were infected during the first half of pregnancy.

In healthy people, parvovirus B19 infection can sometimes affect the ability of the bone marrow (the soft tissue inside bones where blood cells are made) to make new red blood cells, but this effect is usually temporary and does not cause significant anemia or other problems.

Can Fifth Disease Be Prevented?

There is no vaccine to prevent fifth disease. The best way to prevent the spread of infection is to practice good hygiene, including frequent hand washing and not sharing drinking glasses and eating utensils. Because the disease is most contagious before the telltale rash appears, it is difficult to keep the infection from spreading among family members or young children in school or day care. By the time the rash appears and the illness is diagnosed, the person is usually no longer contagious.

* blood transfusions (trans-FYOO-zhunz) are procedures in which blood or certain parts of blood (such as specific cells) are given to a person who needs them because of illness or blood loss.

See also
Measles (Rubeola)
Rubella (German Measles)



U.S. Centers for Disease Control and Prevention (CDC), 1600 Clifton Road, Atlanta, GA 30333. The CDC provides fact sheets about fifth disease at its website.
Telephone 800-311-3435

Website . KidsHealth is a website created by the medical experts of the Nemours Foundation and is devoted to issues of children's health. It contains articles on a variety of health topics, including fifth disease.

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