Fifth Disease (page 2)

Fifth disease, which is especially common in kids between the ages of 5 and 15, usually produces a distinctive red rash on the face that makes a child appear to have a "slapped cheek." The rash then spreads to the trunk, arms, and legs.

About Fifth Disease

Fifth disease is actually just a viral illness that most kids recover from quickly and without complications.

Fifth disease (also called erythema infectiosum) is caused by parvovirus B19. A human virus, parvovirus B19 is not the same parvovirus that veterinarians may be concerned about in pets, especially dogs, and it cannot be passed from humans to animals or vice versa.

Studies show that although 40% to 60% of adults worldwide have laboratory evidence of a past parvovirus B19 infection, most can't remember having had symptoms of fifth disease. This leads medical experts to believe that most people with a B19 infection have either very mild symptoms or no symptoms at all.

Fifth disease occurs everywhere in the world. Outbreaks tend to happen in the late winter and early spring, but there can be sporadic cases of the disease throughout the year.

Signs and Symptoms

Fifth disease begins with a low-grade fever, headache, and mild cold-like symptoms (a stuffy or runny nose). These symptoms pass, and the illness seems to be gone until a rash appears a few days later.

The bright red rash usually begins on the face. Several days later, the rash spreads and red blotches (usually lighter in color) extend down to the trunk, arms, and legs. The rash usually spares the palms of the hands and soles of the feet. As the centers of the blotches begin to clear, the rash takes on a lacy net-like appearance. Kids younger than 10 years old are most likely to get the rash.

Older kids and adults sometimes complain that the rash itches, but most kids with a rash do not look sick and no longer have fever. Certain stimuli (including sunlight, heat, exercise, and stress) may reactivate the rash until it completely fades. It may take 1 to 3 weeks for the rash to completely clear, and during that time it may seem to worsen until it finally fades away entirely.

Other symptoms that sometimes occur with fifth disease include swollen glands, red eyes, sore throat, diarrhea, and rarely, rashes that look like blisters or bruises.

In some cases, especially in adults and older teens, an attack of fifth disease may be followed by joint swelling or pain, often in the hands, wrists, knees, or ankles.

Diagnosis

Doctors can usually diagnose fifth disease by the distinctive rash on the face and body. If a child or adult has no telltale rash but has been sick for a while, a doctor may perform blood tests to see if the illness could be caused by parvovirus B19.

Treatment

Fifth disease is caused by a virus, and it cannot be treated with antibiotics used to treat bacterial infections. Although antiviral medicines do exist, none are currently available to treat fifth disease. In most cases, this is such a mild illness that no medicine is necessary.

Usually, kids with fifth disease feel fairly well and need little home treatment other than rest. After the 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 the doctor for advice about relieving discomfort. The doctor may also recommend acetaminophen for fever or joint pain.

Complications

The majority of kids with fifth disease recover with no complications. By the time the rash appears and while it's present, they usually feel well and are back to their normal activities.

However, some children with weakened immune systems (such as those with AIDS or leukemia) or with certain blood disorders (like sickle cell anemia or hemolytic anemia) may become significantly ill when infected with parvovirus B19. Parvovirus B19 can temporarily slow down or stop the body's production of the oxygen-carrying red blood cells (RBCs), causing anemia.

When a child is healthy, this slowdown of RBC production usually goes unnoticed because it doesn't affect overall health. But some kids who are already anemic can become sick if their RBC production is further affected by the virus. The RBC levels may drop dangerously low, affecting the supply of oxygen to the body's tissues.

When to Call the Doctor

Call the doctor if your child develops a rash, especially if the rash is widespread over the body or accompanied by other symptoms.

If you're pregnant and develop a rash or if you've been exposed to someone with fifth disease (or to anyone with an unusual rash), call your doctor or midwife.

Reviewed by: Joel Klein, MD
Date reviewed: September 2010