Roseola infantum

Measles

The original measles is Rubeola, also known by the monikers measles, the hard measles, the seven day measles, and the red measles. All of these names imply that this illness is much stronger than the other commonly known forms of measles, German measles and roseola infantum.

Measles is caused by a virus in the influenza family. In fact, measles illness is similar to influenza with the addition of a typical rash. Symptoms include high fever for several days, red, watery eyes, runny nose, chesty cough, headaches, and body aches. Children affected with this sickness are quite ill in appearance. The rash appears after the fever has been present a day or two and consists of red spots up to about an eraser head in size. The spots usually begin around the head and neck and, over three to five days, spread down towards the feet. Characteristically, small white spots appear in the mouth opposite the upper middle molars at about the time the rash begins and lasts for a day or two. The presence of these spots with a typical measles-like illness confirms the diagnosis.

Measles is a very potent illness with frequent, serious complications. Some of these complications are from the spread of the virus and include ear infections, pneumonia, encephalitis (infection of the brain), and laryngotracheobronchitis (croup). Others are from secondary bacterial infections such as ear infections and pneumonia, the latter being quite serious. Children under age one, teenagers and adults, and children with immune defects are especially susceptible to serious complications.

The virus is spread mainly by contact with infectious droplets (especially from the nose and throat). The incubation period is about ten days (give or take a couple of days). Children are contagious from about a day before becoming ill to about four days after the rash begins.

There is no cure for measles. Fortunately, we have wonderful prevention, the measles vaccine. In the United States this live-virus vaccine is routinely given to one-year-old children and works quite well. Singlehandedly, it has made measles a very unusual illness in this country. In fact, only 288 cases of rubeola were reported to the Centers for Disease Control and Prevention in 1995. Unfortunately, more than one-third of these were reported in my home state, sunny California. Around five percent or so of children receiving this vaccine do not have a sufficient immune response so that a "booster" immunization is advised. There is some controversy about when is the best time to give the booster. Some give it at age three, others at age five, and still others at age ten or so. Almost all give it prior to puberty. This strategy is altered during community outbreaks and in special cases.

Since the vaccination program has been so successful, measles is rarely seen these days. Most young doctors have never seen a case. However, the word "measles" has developed a type of notoriety and this label is frequently used by parents for any illness that consists of a fever and rash. For this reason, all parents should be familiar with real measles.

Rubella

Rubella is also known as German measles or the Three Day Measles. More appropriately it should be called the "No Days Measles" because half of the people developing this illness show little or no obvious symptoms. Those children with symptoms from this infection usually develop very mild signs such as low grade fever, mild aches and pains, and a rash consisting of small red dots (smaller in size than rubeola) over the whole body lasting one to three days. Some swelling of the lymph glands at the back of the neck is common. A mild, transient arthritis weeks after the infection may be present in both natural disease and after vaccine administration, especially postpubertally.

The virus is spread through contact with nose and throat secretions. The incubation period after contact is two to three weeks. Children are contagious from at least a few days before the onset of rash or fever until at least one week after these signs develop. Sometimes this virus is shed for week.This long contagious period coupled with lack of symptoms in so many people makes this a particularly contagious illness.

Because of extremely mild symptoms in sick children, rubella would be an insignificant illness except for one situation. Rubella illness in a pregnant mother, especially in the first trimester, is associated with a large number of serious fetal defects including blindness, deafness, mental retardation, and damage to vital organs.

Fortunately, these heartbreaking situations have become rare thanks to the rubella vaccine. The incidence of rubella has declined by more than 99% since the prevaccine era. In 1995, only 200 cases of rubella were reported to the CDC. Of course, we may still be missing many cases of childhood rubella due to the minimal symptoms present in affected individuals. But, only seven cases of congenital rubella were reported last year. That number is probably accurate since these cases are hard to miss. Times have changed. I saw more than seven cases of congenital rubella myself in just one year of pediatric residency in 1968. This vaccine has saved countless thousands of infants and children from needless suffering.

Rubella vaccine is most commonly combined with rubeola vaccine and given as a rubeola-rubellamumps combination. Like rubella vaccine, a booster is given prior to puberty to confer better protection.

My main contact with this disease currently is when a parent calls me and tells me that their child has "measles." I immediately know that this is extremely unlikely because vaccines have reduced the incidence of both rubeola and rubella to rare occurrences. In addition, children with rubeola are seriously ill, and the fine, red rash associated with rubella is indistinguishable from numerous other illnesses, most of them viral. In fact, doctors can't accurately diagnose rubella by examining the child. The diagnosis can only be made with certainty by blood tests. Usually two blood samples are necessary. One is done at the time of illness and the other several weeks later.

Roseola

This illness is sometimes called "baby measles." It is also know as rosella infantum, exanthem subitum, and sixth disease. Actually, its most accurate medical name is now human herpesvirus 6 (HHV-6), the virus that was found to cause this malady about eight years ago.

This is a common illness that we are learning more about each year. If you have children, they will get this disease. Since almost everyone gets this infection in early childhood, adult females are immune and have protective antibodies to this virus. This antibody is transferred to the fetus during pregnancy. The fetal antibody level slowly declines after birth. The result of these changes is that very few infants develop human herpesvirus 6 infections in the first few weeks of life. After sufficient maternal protecting antibody has left the infant's system, usually between three and six months of age for this virus, the incidence of infection rapidly rises. Infection rates peak between six to twelve months of age. Almost all infants have had this virus and are immune by two year of age.

The incubation period is probably around ten days. The characteristic roseola symptoms include abrupt onset of illness with high fevers and lethargy lasting three to five days. For some reason, children become much more irritable the first day of the rash. There is no specific treatment for roseola.

Fever-associated seizures are relatively common with this illness. Unlike most simple febrile seizures that occur early in the course of a viral infection in young children, seizures associated with the roseola virus often occur late in the febrile illness.

We now know that this "typical" roseola course of illness only occurs in 20% of human herpesvirus 6 infections in this country. The most common presentation is probably high fever lasting a few days without a subsequent rash. The prevalence of rash after the febrile illness is much higher in Japan for some reason. Some children will even have mild vomiting or diarrhea. Others may have sores in the mouth. Specific red bumps are found in the back of the soft palate frequently in children in Japan. Mild cold symptoms may also be present. Infrequently, children have very mild or no significant symptoms with HHV-6 infection.

Dr. Pellman's column appears monthly in Pediatrics for Parents. He's a Board Certified Pediatrician practicing in Huntington Beach, California, a Clinical Professor of Pediatrics at the University of California, and a Medical Associate of the La Leche League International. He welcomes your comments, criticisms, and suggestions.

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