Sudden exanthema

"The prognosis is excellent in the vast majority of cases. The exanthema can recur, although it is not very frequent".


The sudden exanthema is an illness caused by virus that mainly affects children between the ages of 4 months and 2 years. 

It is transmitted by blood and saliva.

Dermal lesions are pink or red spots that bleach with pressure. They first appear on the trunk and neck and then spread to the arms, legs and face. 

What are the symptoms of a sudden rash?

The characteristic clinic consists of two or three days of high fever normally associated with a good general condition and without previous symptoms.

With the disappearance of the fever, a pinkish pointed exanthema (pimples) appears, which begins to appear in the chest and then spreads to the face, abdomen and, to a lesser extent, to the extremities. This rash lasts between one and two days. 
In the cases that present prodromal symptoms these are limited to a minimum clear rhinorrhea, conjunctival hyperemia, with or without palpebral edema, and pharyngeal inflammation. There may be some small cervical adenopathy and less frequently occipital adenopathy.

The most common symptoms are:

  • Fever.
  • Pointed pink rash.

Does your child have any of these symptoms?

You may have a sudden rash

What are the causes of sudden exanthema?

Its most frequent agent is the human herpes virus 6 although cases caused by the human herpes virus 7 have also been described.

There are two types of human herpes virus 6: type A and type B. 99% of the cases of roseola are caused by type B.

The incubation period ranges from 5 to 15 days. The reservoir of human herpes virus 6 is usually the adult who has been in contact with the virus.

What are the complications of the sudden rash?

Although rare, infection with human herpes viruses 6 and 7 can present complications.

Of these, the most frequent are febrile seizures during the pre-exanthemic period in primoinfection with human herpes virus 6. These febrile seizures are usually not serious.

Some cases of direct involvement of the central nervous system have been described as causing the seizures. There have been some cases of encephalitis and hepatitis in immunocompromised patients.

¿Cómo se diagnostica el exantema súbito?

El diagnóstico del exantema súbito se basa fundamentalmente en la edad, la historia clínica y los hallazgos clínicos. 

En la analítica se detecta una leucocitosis en la fase febril. En cambio, en el período exantemático destaca leucopenia con linfomonocitosis y neutropenia.

Hay que diferenciarla de otras enfermedades exantemáticas como la rubeola, el sarampión y la escarlatina. Se produce una reacción similar en las hipersensibilidades a fármacos.

También, sobre todo al inicio del cuadro y al acompañarse en ocasiones la fiebre de inflamación de la faringe y de la membrana timpánica, podría confundirse con una faringitis o una otitis.

How is the sudden exanthema treated?

Since it is a benign disease, treatment with antivirals is not considered. Due to the good general condition that patients usually present, there is also no need for major symptomatic treatment measures.

Children who are irritable or have some discomfort may benefit from treatment with paracetamol or ibuprofen.

It is important to give a good contribution of liquids especially in the febrile phase.

Where do we treat it?


The Department of Pediatrics
of the Clínica Universidad de Navarra

All our specialists work exclusively and, in addition, since we have all the technology in the same center, we offer the performance of tests and diagnosis in less than 72 hours.

We have a team of highly qualified professionals to attend the different specialized units: Oncopediatrics, Neuropediatrics, Endocrinopediatrics, Neonatology, etc.

Organized in specialized units

  • Neonatology Area.
  • Pediatric Endocrinology.
  • Pediatric Cardiology.
  • Pediatric Neuropediatrics.
  • Digestive and pediatric nutrition.
  • General and preventive pediatrics.
  • Pediatric Pneumology.
Imagen de la fachada de consultas de la sede en Pamplona de la Clínica Universidad de Navarra

Why at the Clinica?

  • Comprehensive care of the child.
  • Professionals who are experts in the different areas for a better diagnosis and treatment.
  • Equipped with the latest technology for newborn care.

Our team of professionals