Listen to this story



Childhood exanthematic disease: sudden postfebrile rash and infectious erythema

Maria Fernanda
5 min read

Eruptive diseases of childhood are very common, but there are some that are not well known, such as sudden posfebrile rash and erythema infectiosum.

You do not have to be alarmed! It is not a disease without a cure. Generally, these pathologies are caused by a viral microorganism.

What is sudden postfebrile rash?

As its name indicates, it is a rash that appears after the decrease in fever, in infants and preschoolers under 3 years of age.

In addition to this, this disease is known by other names such as 6th day disease and roseola.

Childhood exanthematic disease: sudden postfebrile rash and infectious erythema
Crying baby

At the same time, the rash may persist for 2-3 days. Now, how is the eruption? It is characterized by small raised spots, called papules.

In addition, the papules are very reddish and have a distribution from the head to the feet.

Likewise, its appearance usually predominates on the face, neck, trunk and proximal part of the extremities. Also, they are small papules, with a diameter between 2 and 5 mm.

What Causes Sudden Postfebrile Rash?

The cause of the eruptive is a virus belonging to the Herpes viridae family, specifically, the virus is called Herpes Virus type 6 (HHV-6).

Epidemiologically, the only host for the virus is man. In addition, the transmission mechanism is through human secretions, that is, the drops expelled with coughing or sneezing.

In this way, the virus can be transmitted from one person to another. Likewise, the age peak with the highest incidence is between 6 and 24 months.

However, it is not often that before 3 months of age and after 4 years, the virus can cause infection.

The reason it is not common before 3 months is because the newborn still has the mother's antibodies to the virus available.

What happens in the body in the presence of the virus?

The pathological mechanisms are not known to date. It is unknown why the post-fever rash occurs.

However, one possible theory is that the virus is neutralized in the skin when it reaches the end of viremia. Understanding that viremia is the phase in which the virus manages to reach the bloodstream.

What is known is the incubation time of the virus, which is 9 to 10 days.

The fever can last 3 to 5 days, unusual is that it is not disabling. This means that children remain active.

Can other symptoms appear?

It is not common, but symptoms other than fever and rash may appear.

These manifestations are neurological, one of them being febrile seizures and encephalitis.

On the other hand, there is a probability of liver damage such as hepatitis, but in liver transplant patients.

Additionally, it causes elevation of liver enzymes, corresponding to organ damage. In addition to this, it could lead to tonsillitis and lymphadenopathy.

Treatment of sudden posfebrile rash

As it is a viral disease, it does not have a determined or specific treatment. Then the symptoms are treated, in this particular case it would be the fever.

Childhood exanthematic disease: sudden postfebrile rash and infectious erythema

Very well! You have already learned about the post-fever rash. Now, it is the turn of another rare disease, infectious erythema.

What is fifth disease?

Fifth disease is a disease that affects more prevalently in children whose immune system is deficient, this means that it does not respond adequately to infections.

It consists of a pathology that can appear between 4 and 10 years of age. Unlike the previous one, infectious erythema is a large red erythema that appears on the cheeks.

An important fact is that this spot extends to the extremities, its main characteristic being that it does not follow a pattern from head to toe, it usually appears only on the trunk and thighs.

Cause of infectious erythema

Of course, the causative microorganism of erythema is Parvovirus B19, it is a DNA virus. The reservoir is man and the incubation period is approximately 4 to 20 days.

The transmission mechanism is through respiratory secretions and the transplacental route. Exactly, in pregnant women with the infection they can transmit the disease to the fetus.

Symptoms of fifth disease

It usually occurs with erythema and no other symptoms, but if any other symptoms occur, it may be fever, malaise, muscle pain, and headache. These symptoms can last from 7 to 9 days.

Childhood exanthematic disease: sudden postfebrile rash and infectious erythema
General discomfort

In relation to, the erythema is itchy and disappears within a week or 3 weeks.

Treatment of infectious erythema

It does not have a treatment, what they can treat are the symptoms and possible complications.

Thus, the real treatment is prevention. One measure that you can apply at home is proper handwashing.

Viral infections are very common in children, especially when they are young, because they want to put all objects in their mouths.

Can the child go to school with the exanthematic disease?

In both cases, as these are contagious diseases, it is recommended that during the clinical picture, the child does not attend school.

Once you feel better and have no fever, you can go back to your school activities.

Childhood exanthematic disease: sudden postfebrile rash and infectious erythema
Children at school

When is it necessary to consult a doctor?

The onset of these diseases is not specific, which means that it does not have exclusive symptoms of the disease.

As a parent, what you can do is identify the warning signs.

So, if the child already has a fever for more than 48 hours or complies with some of these aspects, it is necessary that you consult the doctor.

  • Newborn with fever

  • The child is very irritable or crying does not stop

  • If it looks in poor general condition

  • Presence of a rash