Sixth disease (exanthema subitum or roseola infantum), a benign, contagious disease that is common in infancy and usually causes a rash, is most often seen in children between 6 months and 3 years of age. 95% of patients are under 3 years old, and it is most common at around 9 months. During the first 6 months, antibodies passed through the umbilical cord in the womb protect the baby. These antibody levels, which are around 90% in the newborn period, fall to 40–50% at 4–6 months.
Although it is more common in spring and autumn, it can be seen all year round. The viruses that cause the disease are of two types, A and B, and in most cases the cause is type B. With type B, once the disease has been had it does not recur and lifelong immunity develops. With type A, however, the virus can become active again in the body when immunity is suppressed. Rarely, the disease can recur with a different type.
The most important sign of sixth disease is the high fever seen before the rash. During the illness the child’s temperature may rise to 39–39.5 degrees. In addition, signs such as mild bluish discolouration of the hands and feet, shivering and restlessness may appear. Sometimes febrile convulsions (fits) may also occur.
Because the period before the rash is a feverish period, it can be confused with many conditions that cause fever (such as teething and upper respiratory and urinary tract infections). As it occurs in infancy, families often attribute the fever before the rash to teething.
The rash period, in turn, can be confused with other childhood rash illnesses (such as measles, rubella and scarlet fever), drug allergy or meningococcal meningitis. For this reason, so that important diseases are not missed, a patient with a rash should be seen and the diagnosis made by a doctor.
There may also be headache, nausea, vomiting, drowsiness, loss of consciousness and delirium. If the child is not taking enough fluids, dry skin, slightly sunken eyes and weakness may be observed. A pink skin rash that starts on the trunk and spreads to the arms must always be taken seriously. In other childhood illnesses the rash usually starts on the neck and face. As soon as the rash appears, it starts to fade within a few hours. The rash disappears within 2–3 days of the start of the illness and does not leave permanent marks.
Precautions must be taken against the risk of transmission!
Droplets spread into the air when the sick child coughs or sneezes can pass the disease on to others. Everyone around the child spreading them is at risk. Because transmission is via the respiratory tract, crowded environments carry a great risk for babies. All children with a feverish illness should be isolated from other healthy babies.
A doctor must be consulted!
* If the rash starts before the child’s fever has come down,
* If the fever returns after the 3–4 day feverish period has passed,
* If there is drowsiness, a tendency to sleep or hallucinations,
* Severe headache,
* If there is neck stiffness and repeated vomiting,
* If there are signs of dehydration and the child’s general condition is poor, a doctor should be consulted again.
Sixth disease is difficult to diagnose. If the child’s fever returns after coming down, the rash starts before the fever has come down, or there is drowsiness, seeing things and delirium, severe headache, stiffening of the neck or difficulty moving it, repeated vomiting, difficulty breathing, chest pain or a severe cough, a paediatrician must be consulted.
The illness can last up to 1 week. It is not a dangerous disease and does not require specific treatment. However, febrile convulsions can occur in 6–15% of cases during the 3–4 day period of high fever. In some patients, especially those with a suppressed immune system, inflammation of the lungs, brain tissue and liver can rarely occur.
It does not require antibiotic treatment. Plenty of fluids and rest are important. Fever-reducing medicines can be used and lukewarm baths given to bring the temperature down and reduce the risk of febrile convulsions. In people with suppressed immunity, or in cases with inflammation of the lungs, brain or liver, antiviral treatment should be given in hospital at a specialist centre.
There is no vaccine yet. Because it is not very contagious, isolation is not recommended. Following hygiene rules and frequent hand washing are appropriate methods of protection.