context: When your child has a primary immunodeficiency disease ( PIDD), his body has a harder time fighting germs that make people sick. He may get a lot of infections in his ears, lungs, skin, or other areas that take a long time to go away. Most cases happen in babies or young children, but sometimes it doesn't show up until adulthood. There are many different types -- more than 200 -- and they affect different parts of the immune system. All make it more likely that he'll get sick from infections. Everyone with a PIDD has a different experience. If your child has it, in most cases he'll be able to go to school and make friends like other kids. As an adult with a PIDD, he'll be able to work and have an active, normal life. If your child's PIDD is mild, he may need to take medicines to treat the infections he gets. Doctors treat some of the more serious types of PIDD with doses of antibodies to fight infections. He'll get these antibodies through an IV in his veins. The treatment takes several hours, and he'll need one every few weeks. Some severe forms of PIDD may need even more serious treatment: a bone marrow transplant, which has a long recovery time. When you first learn that your child has a PIDD, you might worry that infections are going to rage out of control. But there are lots of treatments that can keep symptoms in check and help your child stay healthy and active. You don't have to face this alone. Reach out to family and friends for emotional support. Talk to your doctor about how to meet other families who have faced PIDDs, too. They'll understand what you're going through. You can't catch PIDDs like you can a cold or the flu. Your child has it because he was born with a broken gene that affects his immune system. Sometimes this problem runs in families. Or it may have happened on its own. Normally, your body's white blood cells fight infections. Some people with PIDDs are missing certain types of white blood cells, or those cells don't work very well. If that's true for your child, he's more likely to get sick from infections that wouldn't take hold in someone else. You may not notice any symptoms until your child is a few months old. He may get a lot of serious infections, or his illness may start out as a common cold but turn into bronchitis or pneumonia. Signs that your child may have a PIDD include: Has four or more infections a year in the ears, lungs, skin, eyes, mouth, or private parts Needs to get antibiotics through an IV for infections Gets more than one severe, fast-moving illness, like septicemia, a bacterial infection of the blood Has thrush (a fungal infection in the mouth) that doesn't go away Antibiotics don't work well Gets pneumonia more than once a year Your doctor will do a physical exam and may ask you questions like: Has your child had a lot of severe infections? If so, how long do they last? Does your child stay sick even after taking antibiotics? Do other people in your family tend to get sick a lot? Your doctor may also want your child to get some blood tests. He'll draw some blood and send it to a lab to get it analyzed. Some tests will count the number of white blood cells that your child's body has. Other tests will measure certain proteins that fight disease, called immunoglobulins. Many states now test newborns for the most severe kind of PIDD, called SCID (severe combined immunodeficiency). What else could cause these symptoms? How can I keep my child from getting sick? What reactions should I expect from the treatment? Should my child get all the usual vaccines? Does my child need to stay away from some sports? Infections are going to happen, but treatments can take care of symptoms so your child can get well ASAP and get back to doing his favorite things. He may need to get higher doses of infection-fighting medications and take them for a longer time. If an infection is serious, your child might need to get antibiotics put into his veins through an IV. Even if he's not sick now, your doctor may give him antibiotics or other medicines to prevent an illness. Your doctor may also suggest treatments that can make your child's immune system work better: Immunoglobulin ( Ig) replacement therapy. These are disease-fighting proteins called antibodies that your child needs. Doctors usually give it through a needle, by IV. The antibodies only last so long, so your child may need a treatment every 3 or 4 weeks. He might have some side effects such as achy muscles or joints, headaches, or a low fever. Stem cell transplant. It's rare, but for a very severe PIDD, your child could need a stem cell transplant. In some cases, it's a cure. Stem cells help make new blood cells. They come from bone marrow, which is the soft center of the bones. For a transplant, a donor supplies stem cells with unbroken genes. Your child will need to find someone who is the right match so that his body accepts the new cells. Close relatives, such as a brother or sister, are the best chance. Someone from the same racial or ethnic background may also be a good donor. If no one you know is a match, you can put your child on a waiting list. During the transplant, your child will get the new stem cells through an IV. He won't feel any pain from this, and he'll be awake while it's happening. It could take 2 to 6 weeks for the new stem cells to multiply and start making healthy, working blood cells. During this time, your child may need to stay in the hospital or, at the very least, make visits every day to get checked by his transplant team. It can take 6 months to a year until the number of good blood cells in his body gets up to normal. Even with a PIDD, your child will be able to go to school, make friends, and keep up with activities. You'll want to meet with his teachers to explain his condition and to let them know he may need to miss classes because of illness more often than other kids. You should also let the school know about medications he'll need to take. Just like anyone else, your child should eat good foods like fruits, vegetables, whole grains, and lean protein. Make exercise a habit, and see that he gets plenty of sleep, too. To keep germs away, wash hands often, lathering up with soap for at least 20 seconds. Teach him to keep rubbing his soapy hands together while singing the " Happy Birthday" song twice, which is long enough to get the job done. You can use an alcohol-based hand sanitizer when soap and water aren't available. Stress can make it harder for his body to fight disease. Encourage him to take time to relax, play, and enjoy hobbies. Massage therapy, exercise, being with people he likes, and prayer or meditation are some other ways to lower his stress. Everyone's experience with a PIDD is different because there are so many types of this disease. Most people, with the right treatment, can live a full and active life. The most severe forms of the disease may be treated, and possibly cured, with stem cell transplants, although that's not an easy process. When your child has this illness, the whole family will need lots of emotional support from people like friends, extended family members, and neighbors. Talk to your doctor about getting in touch with other families who have a child with a severe PIDD and can understand what it's like. The web site of the Immune Deficiency Foundation can help you find a doctor or get in touch with a support group. The site also has information about clinical trials. These test new drugs to see if they're safe and how well they work. Trials are a way for people to try medicines that aren't available to everyone. Your doctor can tell you if this is a good option for your child.