Fifth Disease (Erythema infectiosum) is caused by the parvovirus B19. This is a very mild disease with either no symptoms or a slight runny nose and sore throat. The lacelike rash may come and go for 5 weeks, especially after warm baths, exercise, and sun exposure.

TREATMENT
No treatment is necessary. This distinctive rash is harmless and causes no symptoms that need treatment.

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

ADULTS WITH FIFTH DISEASE
Most adults who get fifth disease develop just a mild pinkness of the cheeks or no rash at all. Adults develop joint pains, especially in the knees, more often than rash. These pains may last 1 to 3 months. Taking a nonprescription ibuprofen product usually relieves these symptoms. An arthritis workup is not necessary for joint pains that occur after exposure to fifth disease.

PREGNANT WOMEN EXPOSED TO FIFTH DISEASE
If you are pregnant and exposed to a child with fifth disease before the child develops the rash, see your obstetrician. Your doctor will do an antibody test to see if you already have had the disease and are protected from becoming infected again. If you do not have antibodies against fifth disease, your pregnancy will need to be monitored closely.

Since this disease may be similar in appearance to more serious illnesses such as scarlet fever, measles and rubella, if your child develops a rash that is itchy, or develops a fever over 101, you should see your family physician.