Viral Exanthem and the Many Different Rashes it Represents

Posted by admin on November 20, 2008 under Rashes | Be the First to Comment

Viral infections in children are often associated with a rash called a Viral Exanthem. Some infections have rashes that are specific for that disease, while others are non specific but imply that a viral infection has happened.

Here we will review the common childhood viral infections and their rashes.

Rubella
Rubella, also known as German measles, is an RNA (ribonucleic acid) virus. For young children, there are usually no symptoms. However, adults and older children are generally symptomatic with fever, enlarged lymph nodes, sore throat, nausea and weakness. The lymph nodes are swollen along the neck and behind the ears.

The rash develops up to five days after the symptoms first occur. The rash is described as pink red macules and papules (small red patches and bumps) that start on the face and neck. The spread is centrifugal, which means that it spreads from the neck down in an outward pattern. This occurs in two to three days and disappears the same way it came. The enanthem (oral rash) has Forchheimer spots, which look like red dots (petechiae) on the hard palate.

Children with rubella need to stay home from school for seven days after the onset of the rash, since it is transmitted by respiratory droplets. Usually, treatment is not necessary for young children. However, young adults can complain of arthritis, have thrombocytopenia and encephalitis. The fetus of a pregnant woman with rubella can die or develop congenital rubella syndrome.

Infants are now vaccinated against rubella (MMR) at 12-15 months of age, with a second dose at ages 4-6.

Rubeola
Measles, also called rubeolla, is caused by a paramyxovirus. The vaccine (MMR) is now available and given to children at 12-15 months of age and again at four to six years of age.

In developing countries with limited vaccine availability, this illness is a major health concern. The measles virus is spread through respiratory droplets, but can then spread to the internal organs such as the lungs, liver and gastrointestinal tract.

Initially, the child has a fever, cough, nasal congestion and conjunctivitis. An enanthem (oral rash) called Koplick spots are seen as gray white bumps on the inner cheeks. Then a rash of red patches and bumps begins to appear on the scalp, hairline and behind the ears - spreading to the rest of the body over two to four days. This spread is called cephalocaudad and fades in the same pattern that it started.

Children need to be isolated for four days after the rash begins to appear. Specific tests are available from a physician, including measles-specific IgM antibodies, immunoflourescence from the nose and acute and convalescent IgG antibodies.

Roseola
Roseola infantum is also called sixth disease or exanthum subitum. It is caused by HHV-6 or HHV-7. It commonly occurs between six months and three years of age, most frequently in the spring. Children have a high fever of 104-105 degrees for three to five days, without looking very ill. As the fever fades, the rash appears. The rash is described as pink red patches and bumps (macules and papules) that spread from the neck to the trunk and proximal extremities (upper arms and legs). Seizures from high fever can occur in 10 percent of the children affected. An enanthem of red bumps can be seen on the soft palate and uvula (Nagayama’s spots).

Medication is given to lower the fever and prevent seizures. A physician should be consulted for any additional concerns.

Erythema Infectiosum
Also known as Fifth Disease or “Slapped Cheek Disease,” erythema infectiosum is caused by the DNA human parvovirus B19. It is transmitted by respiratory droplets, and from a mother to her feuts most often in the winter and spring months.

The incubation period lasts four to 14 days. It commonly affects children 4-10 years of age.  Children have mild symptoms with a sudden appearance of a rash. The rash is described as bright red cheeks, not affecting the bridge of the nose and around the mouth. A few days later, lacy red patches appear on the arms. The rash lasts a few weeks.

Fifth disease usually goes away without any complications. However, 10 percent of adults affected can suffer from arthritis and aches in the joints. The hands, wrists and ankles are commonly involved. A low blood count (aplastic crisis or pancytopenia) can also occur in some.  The worst complication is a fetus infected from intrauterine transmission from the mother. It can range from anemia (low blood count) and fetal hydrops, to miscarriage or stillbirth. The risk is high in the first 20 weeks of gestation, with most fetal deaths occurring between 20 and 28 weeks.

Treatment is directed towards the symptoms, as there currently is no antiviral medication against the parvovirus B19. Blood levels of anti B19 IgM antibody can be used to detect infection, particularly in a pregnant woman.

Infectious Mononucleosis
Infectious mononucleosis is caused by Epstein Barr Virus EBV, a DNA virus. The virus is spread by saliva and occurs in children 1-6 years of age and 14-20 years of age.

Typical symptoms include a fever, sore throat and enlarged cervical lymph nodes. People also have a lack of appetite and general weakness. Some have enlarged spleens and liver. The rash is not specific and includes red bumps and patches and red spots (petechiae) on the palate of the mouth. The rash usually shows up following the use of antibiotics such as amoxicillin.

A physician can perform a monospot test, a simple test to detect IgM antibodies for infectious mononucleosis. Treatment is directed at the symptoms only.

Enterovirus
Enterovirus is an RNA virus of the picornavirus family. It is usually spread by respiratory droplets or by the fecal-oral route. It is also transmitted in some swimming pools and is more common in poorer communities.

1. Hand Foot and Mouth Disease is one disease caused by the Enterovirus Coxsackie A16. A young child gets vesicles with redness on the palms and soles. Patients have fever and weakness, which occurs before the rash. In Taiwan, hand foot and mouth disease caused by enterovirus 71 caused pulmonary and brain complications – and in some cases even death.
2. Herpangina affects children 3-10 years of age and causes painful blisters in the mouth on the soft palate, uvula, tonsils, pharynx and inside the cheeks. It is caused by Coxsackie A and B.