Here is a website which may help
http://www.aaaai.org/patients/publicedmat/
tips/recurrentinfections.stm
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People with immunodeficiency get the same kinds of infections that other people get—ear infections, sinusitis and pneumonia. The difference is that their infections occur more frequently, are often more severe, and have a greater risk of complications. Furthermore, the infections usually do not go away without using antibiotics and often recur within one to two weeks after antibiotic treatment is completed. These patients frequently need many courses of antibiotics each year to stay healthy. Patients with some forms of immunodeficiency are more likely than other people to develop infections inside certain areas of the body, such as the bones, joints, liver, heart or brain.
In most cases, the frequency of infection is the most important issue, but sometimes a single infection with an unusual germ is enough to trigger the need for the doctor to perform a thorough immunologic evaluation of the patient.
So, how many infections are too many? Allergist/immunologists often use the frequency of the use of antibiotics to mark the frequency of significant infections. Older children and adults with healthy immune systems seldom require antibiotic treatment. However, for the reasons mentioned above, many younger children receive several courses of antibiotic therapy each year. Therefore, the number of ear infections that may be “normal” in a child under 5 years of age is clearly abnormal in older children and adults.
General guidelines for determining if a patient may be experiencing too many infections are:
The need for more than four courses of antibiotic treatment per year in children or more that two times per year in adults.
The occurrence of more than four new ear infections in one year after four years of age.
The development of pneumonia twice over any time.
The occurrence of more than three episodes of bacterial sinusitis in one year or the occurrence of chronic sinusitis.
The need for preventive antibiotics to decrease the number of infections.
Any unusually severe infection or infections caused by bacteria that do not usually cause problems in most people at the patient's age.
If you have any of the conditions noted above, your allergist/immunologist will consider if you need to be evaluated for immunodeficiency. Very often, this evaluation may give reassuring results and even improve your immunity since immunizations may be part of the evaluation. If an immunodeficiency is detected, early treatment prevents complications of infections that then contribute to making other infections worse and more difficult to treat.
Although small children are expected to have a large number of respiratory infections, it is important to be vigilant in this population for unusually frequent or severe infections. This is because the most serious immunodeficiencies usually become apparent during the first years of life. Signs that a physician should consider examining a patient further for possible immunodeficiency include persistent fungal infection of the mouth or skin, prolonged diarrhea or persistent cough. If a primary care or family physician believes that a patient's infections exceed the normal range, the doctor should consider referring the patient to an allergy/immunology specialist.
The most common forms of immunodeficiency are caused by defects in your ability to produce blood proteins called antibodies. Antibodies are proteins that attach to germs and help the body eliminate them. Simple blood tests can measure the number of antibodies you are producing. To fully evaluate your antibodies, it may be important to measure specific antibody responses by giving you diptheria, tetanus and pneumococcal (pneumonia) vaccines and performing a blood test before immunization and three to four weeks later. Skin tests or more specialized blood tests can diagnose other forms of immunodeficiency. Allergy skin tests are sometimes done because allergies often contribute to infection susceptibility, and many patients with immunodeficiency also suffer from allergies.
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