A lot of viruses with rashes resemble one another. In the case of measles, the issue can become more confusing because two types of measles have similar-sounding names: rubella, or German measles, and rubeola, also called regular or hard measles. Immunity to one type of measles doesn't make you immune to the other. But, in most cases, having German measles once makes your child immune to this disease for life, according to MayoClinic.com. But it's possible to have rubella misdiagnosed, so your child might appear to have it twice.
Description of German Measles
Unlike regular measles, German measles often cause a mild illness. In 25 percent to 50 percent of cases, German measles symptoms are subclinical, with no noticeable symptoms, according to the Centers for Disease Control and Prevention. Cold symptoms such as cough, sore throat or runny nose might precede the rash by about a week. Your child might also have red eyes, swollen lymph nodes and a low fever. The rash, which consists of tiny pink spots, starts around the ears, spreads to the trunk and then to the arms and legs.
How Immunity Develops
The rubella virus causes German measles. After your child is exposed to someone carrying the virus through contact with respiratory droplets, it takes between 12 to 23 days for the symptoms to appear, according to the CDC. As the virus multiples, the body produces antibodies to fight it. When exposed to the virus again, antibodies attack the virus and prevent it from gaining a toehold, usually preventing a person from having the disease a second time.
You might confuse German measles with other diseases that cause a rash, including scarlet fever, Fifth disease, drug rashes, mononucleosis and even regular measles. Rubella is generally much milder than regular measles and scarlet fever. Infectious mononucleosis generally causes longer periods of fatigue. Because rubella can be clinically indistinguishable from other diseases, according to the Merck Manual, a reported history of having had rubella isn't considered proof that a child has had the disease. A blood tests can determine whether your child has actually had rubella.
Rubella After Vaccination
You can have your child vaccinated against the rubella virus. Vaccination provides immunity to rubella in 90 percent to 99 percent of cases, according to the University of Maryland Medical Center. It takes two doses of the vaccine to provide immunity: one at age 12 to 15 months and one between the ages of 4 and 6. Some children develop a fever and rash after rubella vaccination; this doesn't mean they have the disease.