Causes and symptoms of the Sixth disease

More commonly called sixth disease, roseola infantum is an exanthematous disease, typical of early childhood.

Characterized by high fever and the appearance of reddish spots on the skin, generally the sixth disease is mild and resolves spontaneously within a few days.

What is the sixth disease

So called because of the chronological order in which it was identified, the sixth disease is one of the exanthematous diseases (infectious diseases that spread by direct contact and are recognizable by the presence of characteristic red spots).

This infection is very common in the first years of life: in fact, it occurs in the child almost always between 6 months and 2 years, although it can occasionally arise earlier (for example, the sixth disease can occur in a younger child, who has not received specific antibodies from the mother) or, but very rarely, later.

The sixth disease in newborns usually has the same course that is observed in the older child, while in adults (where it is extremely rare) it involves more relevant symptoms.

As well as measles, chickenpox, rubella and infectious erythema (fifth disease) is a viral infection. Let’s see which viruses are responsible.

Causes

As indicated in the table, the infectious agent responsible, which was identified in 1986, is a human herpesvirus belonging to the group of beta-herpesviruses: in most cases it is HHV 6B, in some cases two other similar herpesviruses are involved, HHV 6A and HHV 7.

In the body, the preferred target of these viruses are white blood cells (cells that play an essential role in our immune system), within which they multiply and can survive for a long time in a state of latency. A site of localization and proliferation typical of these viruses are also the salivary glands.

HHV 6B is an extremely widespread virus in the population: a very high percentage of children come into contact with it by 2 years of age, so much so that specific antibodies can be found in 90-100% of adults and adults.

Symptoms

The disease begins in a characteristic way with a sudden feverish rise, which can even exceed 40 ° C and which, in general, lasts between 3 and 5 days.

In children, the increase in temperature, when it occurs so abruptly, can trigger convulsive seizures that – although alarming for parents – are not to be considered dangerous and do not predispose to the onset of epilepsy.

Just as rapid as its onset, is also the remission of fever, which usually occurs on the fourth day (so much so that the disease is also called “three-day fever”) or, if necessary, after being treated with common antifebrile drugs such as paracetamol or ibuprofen.

Generally, fever is not accompanied by other symptoms and does not compromise the general state of children, who, on the contrary, tend to remain awake and active during the febrile phase.

In some cases, however, flu-like symptoms with respiratory or gastrointestinal disorders and an enlarged lymph nodes of the head, neck and ears can be added. In these cases, fever may be associated with:

• general malaise;
• irritability and loss of appetite;
• redness of the pharynx and sore throat;
• swelling of the eyelids;
• conjunctivitis;
• vomiting and diarrhea (rarely).

According to the data, in about a third of children, after a few hours, or at most the day after the regression of fever, a rash appears similar to those of measles and rubella, which, unlike the latter, does not cause peeling of the skin or itching.

The eruption is mainly localized on the trunk and, to a lesser extent, on the limbs and face, and consists of reddened and flat papules (small conical reliefs), a few millimeters in diameter, which can sometimes take on a pale pink color and present a white halo in the surrounding area. In some children, a similar erythematous rash may occur in the oral cavity, at the level of the soft palate up to the base of the uvula.

In the rare cases in which the infection is contracted in adulthood, the symptoms described are more accentuated and represent a danger in the case of immunocompromised subjects.

Course

The disease has an incubation period ranging from 5 to 15 days. The transmission of the infection occurs through the respiratory tract and with saliva (therefore mainly through coughing and sneezing).

Contagiousness is maximum during the febrile phase. Under normal conditions the symptoms resolve spontaneously and quickly without requiring any specific treatment.

In the initial phase, if the temperature is very high, the administration of antipyretics and liquids to counteract dehydration is indicated.

Complications

In healthy subjects the disease is completely benign and the symptoms can also be greatly attenuated.

Complications are very rare and mainly concern subjects (children or adults) with compromised immune defenses. In these cases, in fact, there may be possibly serious damage to the lungs, liver, hematopoietic tissues and central nervous system; Therefore, it is advisable to consult your pediatrician or doctor (as appropriate).

The infection does not seem to pose risks during pregnancy; Moreover, given its prevalence in the general population, the probability that a pregnant woman possesses specific antibodies is very high.

Prevention

In general, special prevention measures are not recommended, however, to reduce the risk of contagion of other children, it may be useful to take some simple precautions. Moms and dads can, in fact, make sure that their children:

• wash hands and face often;
• cough and sneeze inside tissues (which must be thrown away immediately after use);
• do not share glasses, plates and cutlery.

The course of the disease, on the other hand, requires careful surveillance in immunosuppressed subjects for the possibility of serious complications.