Infectious Erythema

Information on the causes, symptoms, and most effective treatments for this viral skin rash.

Symptoms and Causes

Infectious erythema, also known as megaloerythema, is a viral infection caused by parvovirus B19, with a higher incidence in children. As it is characterized by a facial skin rash, it is popularly known as "slapped cheek disease."

Historically, infectious diseases causing skin rashes were classified and always listed in the same order (measles, scarlet fever, rubella, varicella, infectious erythema, and roseola infantum), which is why it is also referred to as fifth disease.

The prognosis of megaloerythema is generally very good, as it resolves completely without sequelae or reduction in life expectancy. However, in patients with underlying conditions or a weakened immune system, complications may occur.

Symptoms

The reddish, reticular-patterned rash (net-like appearance) is the most characteristic symptom of infectious erythema and usually presents as:

Facial rash, especially on the cheeks.
Mild rash on the trunk, arms, buttocks, and legs.

In some cases, other symptoms may occur. These typically appear in the early stages, prior to the onset of the skin rash, such as:

General malaise.
Fever.
Pruritus.
Headache.
Nasal congestion.
In adolescents and adults, joint pain (arthralgia).

In most cases, the rash resolves spontaneously within a few days, although it may persist for several weeks, particularly after sun exposure.

Causes

Infectious erythema is caused by parvovirus B19, which is transmitted from person to person through respiratory droplets released when speaking, coughing, sneezing, or breathing.

The incubation period of megaloerythema ranges from 4 to 15 days, during which the patient remains asymptomatic or presents mild symptoms such as malaise, low-grade fever, nasal discharge, or headache. This is the phase during which transmission may occur, as the disease is generally no longer contagious once the rash appears.

Risk Factors

Factors that increase the likelihood of developing infectious erythema include:

Age: more common in children between 5 and 15 years of age.
Close contact with individuals infected with parvovirus B19.
Immunocompromised patients, who are more prone to infections.

The risk of complications increases in the following cases:

Weakened immune system: may lead to chronic infection.
Pregnancy.
Red blood cell disorders.

Complications

Infectious erythema may lead to serious complications, such as:

Immunocompromised individuals: chronic infection, severe anemia.
Pregnant women: risk of fetal anemia or miscarriage.
Red blood cell disorders: aplastic crisis, a severe form of anemia caused by suppression of erythrocyte production due to megaloerythema.

Prevention

Preventing infectious erythema is difficult, as the disease is asymptomatic during the contagious period. To reduce the risk of contracting viral infections, frequent handwashing, avoiding close contact with individuals with respiratory symptoms, and general respiratory hygiene measures are recommended.

Which physician treats infectious erythema?

Infectious erythema is managed within the specialty of pediatrics. When it occurs in adults, it is treated in family and community medicine consultations.

Diagnosis

The diagnosis of infectious erythema is clinical, as a physical examination revealing the characteristic rash, together with an assessment of accompanying symptoms, is usually sufficient.