Fifth Disease

Picture of fifth disease rash. The rash appears as a red "slapped cheek" on the face and can spread to the trunk, buttocks, and thighs.

• A human parvovirus B19 causes the fifth disease.
• The medical name for fifth disease is erythema infectiosum (EI).
• Symptoms include low fever, fatigue, a "slapped cheeks" rash, joint pains, and a whole-body rash.
• 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.
• Doctors make a diagnosis of the fifth disease based on clinical features.
• 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.
• Rarely, the fifth disease can become complicated.
• After recovery from fifth disease, lifelong immunity is generally guaranteed.
• The fifth disease can cause miscarriage in pregnant women.

The fifth disease is a viral illness caused by human parvovirus B19. Erythema infectiosum and slapped cheek syndrome are other names for the fifth disease. Healthcare professionals first described the fifth disease in 1896 and named the illness the fifth disease because of its fifth position in the numerical classification of six childhood illnesses associated with rashes (exanthems). The virus is highly contagious.

Other numbered viral exanthems included

• measles (rubeola or first disease),
• rubella (German measles or third disease), and
• roseola infantum (sixth disease).

The bacterium Streptococcus pyogenes causes scarlet fever or "second disease." Doctors no longer classify the fourth disease as a clinical entity. Healthcare providers did not rename these illnesses until the molecular era when it became possible to isolate viruses and bacteria.

Parvovirus infection is very common. Almost 50% of adults have had a parvovirus B19 infection but often do not remember having it because this infection frequently does not cause symptoms.

The fifth disease is most commonly seen in children between the ages of 5 and 15, but it can affect people of any age. The virus usually runs its course within a few weeks, and most people recover without any serious complications. However, in rare cases, the virus can cause complications in people with weakened immune systems, such as pregnant women and people with certain blood disorders.

The fifth disease generally occurs in school-age children between 4-10 years of age, but it can affect any age group. Parvovirus infection most commonly occurs during the winter and spring. Here are some of the symptoms and signs that can occur in children and adults who have the fifth disease:

• Early symptoms: The illness classically begins with a low-grade fever, headache, runny nose, sore throat, and malaise (a sense of not feeling well). Of course, these cold-like symptoms mimic any other viral illness, so it is impossible to determine the cause early in the illness.
• After about a week, a characteristic bright red rash on the cheeks (the so-called "slapped cheeks") follows the initial symptoms. Finally, after three to four days, a fine, red, lace-like rash can develop over the rest of the body. This rash may last for five to seven days and occasionally comes and goes for several weeks. The other symptoms are usually gone by the time the rash appears. Patients with the rash are usually not contagious. Unfortunately, as with many other viral illnesses, the features and timing of the different stages of illness are often unpredictable.
• Unlike other viral infections that usually cause hand, foot, and mouth diseases (namely coxsackievirus A16 and enterovirus 71), the fifth disease does not typically involve the palms and soles.
• Joint pains: Around 5% of children and about half of adults with the fifth disease experience joint pains. This arthritis or arthropathy is more common in females than males, is usually temporary, lasting for a few days to weeks, and may become a long-term problem for months. People with arthritis from the fifth disease usually have stiffness in the morning, with redness and swelling of the same joints on both sides of the body ("symmetrical" arthritis). The joints most commonly involved are the knees, fingers, and wrists.
• Complications: While rare, the fifth disease can cause complications in some people, particularly pregnant women, and people with weakened immune systems. In pregnant women, the virus can infect the fetus and cause miscarriage or stillbirth.

The fifth disease is typically a mild illness that resolves on its own within a few weeks, it can cause serious complications in certain individuals.  Here are some of the serious complications of the fifth disease:

• Anemia: Rarely, do these patients develop erythrocyte aplasia, meaning the bone marrow stops forming a normal number of red blood cells (anemia). This complication is rare and usually transient, but anemia can be life-threatening. Patients who have compromised immune systems (by disease or treatment) are at high risk of this complication.
• Pregnancy issues: Pregnant women (who have not previously had the illness) should avoid contact with patients who have a fifth disease. The fifth disease virus can infect the fetus prior to birth. Although no birth defects have been reported because of the fifth disease, for 2%-10% of B19-infected pregnant women, the fifth disease can cause severe anemia and even the death of the unborn fetus (by hydrops fetalis). Blood tests for parvovirus B19 are not routinely included in preconception or antenatal screenings.
• Complications in people with weakened immune systems: Fifth disease can be more severe in people with weakened immune systems, such as those with HIV, leukemia, or sickle cell anemia. These individuals may be at risk for serious complications such as severe anemia or pneumonia.
• Neurological complications: Although the rare, fifth disease has been linked to neurological complications such as encephalitis (inflammation of the brain) and Guillain-Barre syndrome (a rare neurological disorder).
• Joint pain and swelling: In some cases, particularly in adults, the fifth disease can cause joint pain and swelling in the hands, wrists, knees, and ankles. This joint pain can be severe and may last for several weeks or months.

The only available treatment is supportive.

• Fluids, acetaminophen (Tylenol), and rest provide relief.
• Antibiotics are useless against the fifth disease because it is a viral illness.
• People with persistent arthritis can use anti-inflammatory medications such as ibuprofen (Advil) or naproxen (Aleve), though children should not take aspirin due to the risk of developing Reye syndrome.
• Get plenty of rest and avoid strenuous activities, especially during the early stages of the illness when symptoms are more severe.
• Itching: Anti-itch creams or lotions, such as calamine lotions, can help relieve itching caused by the rash.
• Avoid spreading the infection: The virus that causes the fifth disease is contagious, so it is important to avoid close contact with others, especially pregnant women until the symptoms have resolved.

In rare cases, the fifth disease can cause complications that require medical treatment. For example, if a person develops severe anemia, they may need a blood transfusion. Pregnant women with the fifth disease may need monitoring and treatment to protect the fetus. 

• Airborne transmission: Parvovirus B19 usually spreads by droplets.
• The virus spreads whenever an infected person coughs or sneezes.
• The virus can also be transmitted through direct contact with an infected person's respiratory secretions or blood, such as when shaking hands, sharing drinks or utensils, or caring for an infected person.
• Mother-to-fetus transmission: Pregnant women who are infected with the fifth disease can transmit the virus to their fetus through the placenta. This can cause severe anemia in the fetus and lead to miscarriage or stillbirth.
• Environmental surfaces: The virus can survive on environmental surfaces, such as toys or doorknobs, for several hours.
• However, once the rash is present, that person is usually no longer contagious and need not be isolated.

It is important to note that the fifth disease is most contagious before the rash appears, during the early stages of the illness when symptoms are most severe. Once the rash appears, the risk of spreading the infection is lower. If you or your child has a fifth disease, it is important to take precautions to avoid spreading the virus to others, such as washing your hands frequently and avoiding close contact with pregnant women or people with weakened immune systems.

Similar to most viral illnesses, the best way to prevent the spread of the disease is by proper hand washing, by covering your mouth and nose when you sneeze or cough, and by staying home when you become sick.