Erythema infectiosum

Key Points
Common viral illness, often affecting young children
Caused by the B19 papovirus
Initially consist of bright redness in the cheeks, followed by the development of a rash on the arms, legs and torso
Also accompanied by fever in some cases

Fifth disease is a viral illness most common in young children. It initially presents as a marked redness of the cheeks, as if the affected child has been slapped. This is followed by the development of a rash on the arms, legs and torso, which fades from the center. It is also accompanied by fever and/or joint pain in some cases. The rash may persist on and off over several weeks, and heat, exercise and emotional distress may cause it to return.

While Fifth Disease can affect anyone, it is most common in young children. Most adults have antibodies which prevent the virus from affecting them, which suggests that most infections may go unnoticed. Pregnant women are at significant risk if they contract the infection, as it can cause harm to the fetus.

Differential Diagnosis (Other conditions with similar appearance)

Measles
Mumps
Rubella
Roseola Infantum
Scarlet fever
Lupus
Erythematosus

Diagnosis
Key Points
Diagnosis based on appearance of the rash, which is very distinct
Blood tests may be performed to confirm diagnosis or rule out other similar-appearing conditions

Fifth Disease is typically diagnosed based on the appearance of the rash, which is very distinct. Health care professionals may perform blood tests to confirm the diagnosis or to rule out other conditions with similar appearance. Pregnant women must be tested if it is suspected they have been in contact with an affected person.

Treatment
Typically, no treatment is required in affected children
Pain relievers may be administered if the condition is accompanied by fever and/or joint pain
OTC Options: Acetaminophen

Fifth disease is not life-threatening and typically requires no treatment in affected children. If the infection is accompanied by fever and/or joint pain, pain relievers such as acetaminophen may be administered to control these symptoms.