Fifth Disease

The name "fifth” is historic; this infection was counted among the five classical common infections of childhood. KidsHealth.org is a wonderful resource for medical information and was used in the development of this informational guide. 

Signs and Symptoms:
Fifth disease (erythema infectiosum) is a viral illness caused by parvovirus B19. It begins with a low-grade fever, headache, and mild respiratory symptoms (a stuffy or runny nose like a common cold). These symptoms pass, and the illness seems to be gone, until a rash appears 6-11 days later. The rash classically begins on the face as a facial flushing that gives the child a "slapped-cheek" appearance. The rash quickly spreads as red blotches, extending down to the trunk and to the arms and legs, but usually sparing the palms and soles. As the centers of the blotches begin to clear, the rash takes on a lacy net-like appearance.

Older children and adults sometimes complain that the rash itches, but most children with a rash caused by fifth disease do not look sick and have no fever. It usually takes 1-3 weeks for the rash to clear totally, and it may seem to get better or worse at any time during that period.

Certain stimuli seem to reactivate the rash, including sunlight, heat, exercise and stress. Other symptoms that are sometimes rarely seen with fifth disease include swollen glands, red eyes, sore throat, diarrhea, and unusual rashes that look like blisters or bruises.

In some cases, especially in adults and older teens, swelling or pain in the joints may follow an attack of fifth disease. The hands, wrists, knees, and ankles are most often affected.

Description:
School-age children between ages five and 15 are most likely to be infected by this illness. Fifth disease occurs everywhere in the world and community outbreaks of fifth disease tend to happen in the late winter and early spring, but there may also be sporadic cases of fifth disease throughout the year. Studies show that from 40 percent to 60 percent of adults worldwide have laboratory evidence of a past B19 infection, but most of these adults cannot remember having had symptoms of fifth disease. This leads experts to believe that most people with a B19 infection have either very mild symptoms or no symptoms at all. B19 spreads from person to person in fluids from the mouth and throat of someone with a B19 infection, especially via large droplets from coughs and sneezes.

A pregnant woman who has a B19 infection may pass the virus to her unborn child. In most cases this causes no lasting problems for the baby, but rarely the fetus may be infected if the mother has the infection during the first trimester.  If you are pregnant, you should discuss this with your doctor.

Prevention:
There is no vaccine for fifth disease, and researchers do not recommend giving immune globulin to those who have been exposed to fifth disease.  Since the rash of fifth disease is a reaction of the body's immune system AFTER a B19 infection, isolating someone with an fifth disease rash will not prevent spread of the infection because the virus is probably already gone.  By the time fifth disease rash is obvious, the person usually is not contagious.

Incubation:
The incubation period for fifth disease ranges from 4-28 days, with the average being 16-17 days.

Duration:
The rash of fifth disease usually lasts 1-3 weeks.

Contagiousness:
Persons with fifth disease infection can spread the virus in fluids from their mouth and throat, beginning 7-11 days after they have been exposed to the illness. This contagious period falls either during the incubation period or during the time when they have only mild respiratory symptoms (before the rash). Since the rash of fifth disease is an immune reaction AFTER the infection passes, a child with fifth disease rash is usually not contagious.

Home Treatment:
Usually, children with fifth disease feel fairly well and need little home treatment.  Since the fifth disease infection is typically identified by its rash, AFTER fever and mild cold symptoms have passed, there may be little to treat except any discomfort from the rash itself. If your child has itching from the rash of fifth disease, ask your doctor about which lotions or creams might best relieve the discomfort.

Professional Treatment:
A virus causes fifth disease, and it cannot be treated with the antibiotics used to treat bacterial infections. Although antiviral medicines exist, they are not used to treat fifth disease. In most cases, fifth disease is such a mild illness that no medicine is necessary.

If you are pregnant and develop any type of rash, call your obstetrician immediately. If you are pregnant and have been exposed to someone with fifth disease (or to anyone who has an unusual rash), also call your obstetrician.