Fifth Disease Health Article

Definition

Fifth disease is a mild childhood illness caused by the human parvovirus B19 that causes flu-like symptoms and a rash. It is called fifth disease because it was fifth on a list of common childhood illnesses that are accompanied by a rash, including measles, rubella (or German measles), scarlet fever (or scarlatina), and scarlatinella, a variant of scarlet fever.

Description

The Latin name for fifth disease is erythema infectiosum, meaning infectious redness. It is also called the "slapped cheek disease" because, when the bright red rash first appears on the cheeks, it looks as if the face has been slapped. Anyone can get the disease, but it occurs more frequently in school-aged children. The disease is usually mild, and both children and adults usually recover quickly without complications. Some individuals exhibit no symptoms and never even feel ill.

Transmission

The virus that causes fifth disease lives in the nose, mouth, and throat of an infected person; therefore, the virus can be spread through the air by coughing and sneezing. It can also be spread through shared drinking glasses and eating utensils.

Demographics

Fifth disease is very common in children between the ages of five and 15. Studies show that although 40 percent to 60 percent of adults worldwide have laboratory evidence of a past parvovirus B19 infection, most of these adults cannot remember having had symptoms of fifth disease. This fact leads medical experts to believe that most people with parvovirus B19 infection have either very mild symptoms or no symptoms at all.

Fifth disease occurs everywhere in the world. Outbreaks of parvovirus tend to occur in the late winter and early spring, but there may also be sporadic cases of the disease any time throughout the year.

In households where a child has fifth disease, another family member who has not previously had fifth disease has about a 50 percent chance of also getting the infection, while classmates of a child with fifth disease have about a 60 percent chance of getting the disease.

Causes and symptoms

Fifth disease is caused by the human parvovirus B19, a member of the Parvoviridae family of viruses, that lives in the nose, mouth, and throat of an infected person. Because the virus needs a rapidly dividing cell in order to multiply, it attacks the red blood cells of the body. Once infected, a person is believed to be immune to reinfection.

Symptoms may appear four to 28 days after being exposed to the virus, with the average time to onset ranging from 16 to 17 days. Initial symptoms are flu-like and include headache, stuffy or runny nose, body ache, sore throat, a mild fever of 101°F (38.3°C), and chills. It is at this time, prior to the development of the rash, that individuals are contagious. These symptoms last for two to three days. Other symptoms that sometimes occur with fifth disease include swollen glands, red eyes, and diarrhea. In older teens and adults, fifth disease may be followed by joint swelling or pain in the hands, wrists, knees, and ankles, lasting from a few months to several years.

In children, especially those under the age of ten, a bright red rash that looks like a slap mark develops suddenly on the cheeks a few days after the original symptoms were experienced. The rash may be flat or raised and may or may not be itchy. Sometimes, the rash spreads to the arms, legs, and trunk, where it has a lace-like or net-like appearance as the centers of the blotches fade. By the time the rash appears, individuals are no longer infectious. On average, the rash lasts for ten to 11 days but may last for as long as five to six weeks. The rash may fade away and then reappear upon exposure to sunlight, hot baths, emotional distress, or vigorous exercise.

The virus causes the destruction of red blood cells and, therefore, a deficiency in the oxygen-carrying capacity of the blood (anemia) can result. In healthy children, the anemia is mild and only lasts a short while. In children with weakened immune systems, however, either because they have a chronic disease like AIDS or cancer (immunocompromised) or are receiving medication to suppress the immune system (immunosuppressed), such as organ transplant recipients, this anemia can be severe and last long after the infection has subsided. Symptoms of anemia include fatigue, lack of color, lack of energy, and shortness of breath. Some individuals with sickle cell anemia, iron deficiency, a number of different hereditary blood disorders, and those who have received bone marrow transplantations may be susceptible to developing a potentially life-threatening complication called a transient aplastic crisis in which the body is temporarily unable to form new red blood cells.

In very rare instances, the virus can cause inflammation of different areas of the body, including the brain (encephalitis), the covering of the brain and spinal cord (meningitis), the lungs (pneumonitis), the liver (hepatitis), and the heart muscle (myocarditis). The virus can also aggravate symptoms for people with an autoimmune disease called systemic lupus erythematosus.

Although no association with an increased number of birth defects has been demonstrated, there is concern that infection during the first three months of pregnancy may lead to a slight increase in the number of miscarriages due to the fetus developing severe anemia. There is also some concern that infection later in pregnancy may involve a very small risk of premature delivery or stillbirth. As a result, women who get fifth disease while they are pregnant should be monitored closely by a physician.