What is the organism (if any) of fifth disease (erythemia infectiosum)

Especially common in children between the ages of 5 and 15, fifth disease typically produces a distinctive red rash on the face that makes the child appear to have a slapped cheek. The rash then spreads to the trunk, arms, and legs. Despite being called a "disease," fifth disease is actually just a viral illness that most children 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 of these adults 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 of parvovirus tend to happen in the late winter and early spring, but there may also be sporadic cases of the disease any time 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 typically 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. Children younger than 10 years of age are most likely to get the rash.