health

Fifth disease, sometimes called slapped-cheek disease, is an infection
caused by the virus human parvovirus B19. Its most characteristic feature
is a bright red rash that begins on the face, making the cheeks look as if
they have been slapped. After a few days, the rash may spread down the
body and onto the arms and legs. As it spreads, the rash takes on a pink,
lacy appearance.
Most people with fifth disease have mild symptoms and do not become
seriously ill; some may not have any symptoms at all. However, the disease
can be serious for people with certain blood disorders, such as sickle-cell
disease, because parvovirus B19 can temporarily cause or worsen existing
anemia. For most people, temporary anemia is not a problem, but for
those who already have anemia, the condition can become severe, causing
paleness, fatigue, and a fast pulse. People with weakened immune systems,
such as those who have AIDS, cancer, or who have had an organ transplant,
can also develop severe anemia as a result of fifth disease.
Parvoviruses can infect animals, but these are not the same strains
that affect humans. Therefore, a person cannot catch fifth disease from a
dog or cat, and a pet cannot catch it from an infected person.