A fifth disease rash is caused by parvovirus B19, according to the Centers for Disease Control and Prevention. This condition is a contagious viral infection that spreads through respiratory secretions, including nasal mucus and saliva.
Also referred to as erythema infectiosum, fifth disease is common in children aged between 5 and 15 years old, states KidsHealth. It appears as a red rash on the face, and it spreads to the arms, trunk and legs. The rash can be itchy, particularly on the soles of the feet, notes the CDC. After the rash appears, the disease is no longer contagious. Its early symptoms include a headache, low-grade fever and a runny nose.