When Your Child Has Fifth Disease

By Barton D. Schmitt, M.D.

Fifth disease is a very mild disease characterized by a bright red or rosy rash on both cheeks for one to three days ("slapped cheek" appearance) followed by a pink "lace-like" or "net-like" rash on the extremities. The "lacey" rash appears primarily on the thighs and upper arms. It comes and goes several times over a period of one to three weeks, especially after warm baths, exercise, and sun exposure. The rash does not itch. Your child may have a low-grade fever (less than 101 F), slight runny nose, and sore throat or no other symptoms besides the rash.

Fifth disease is caused by the human parvovirus B19. It was so named because it was the fifth pink red infectious rash to be described by physicians (the others are scarlet fever, measles, rubella, and roseola). Once your child has had the virus, he is protected from becoming infected again.

Treatment

No treatment is necessary. This distinctive rash is harmless and fifth disease causes no symptoms that require treatment. Sometimes the diagnosis can be made by telephone.

Your child can go to school

Over 50% of children exposed to fifth disease will come down with the rash in 10 to 14 days. Because the disease is contagious mainly during the week before the rash appears, a child who has the rash is no longer contagious and does not need to stay home from school or day care.

When adults get fifth disease

Most adults who get fifth disease develop just a mild pinkness of the cheeks or no rash at all. More adults develop joint pains, especially in the knees, than a rash. These pains may last one to three months. Taking a non-prescription ibuprofen product usually relieves them.

Precautions for pregnant women

The virus that causes fifth disease doesn't cause birth defects. Recent research has shown, however, that 10% of babies who are infected with fifth disease before birth develop severe anemia and 1% or 2% may even die. If you are pregnant and exposed to a child with fifth disease before the child develops the rash, see your obstetrician. He or she will take a sample of your blood for an antibody test to see if you have already had the disease and are protected from becoming infected again.

Call our office during regular hours if:

1. The rash becomes itchy.

2. Your child develops a fever over 101 F (38.4 C).

3. You feel your child is getting worse.

4. You have other concerns or questions.