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About primary immunodeficiency

We all get sick from time to time, and we count on our immune system to help us get better. However, for people with an inherited primary immunodeficiency (PI) disease, getting sick can be a frequent, serious ordeal. That’s because their immune system does not work as it should.

Researchers have identified more than 150 different types of primary immunodeficiency disease (also known as primary immune deficiency disease). It’s difficult to accurately estimate how many individuals in the US have some form of PI disease, but we know that it’s more common than once thought. One survey estimates that 1 person in every 1,200 is living with primary immunodeficiency, though many of them remain undiagnosed.

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Symptoms of primary immunodeficiency

While many types of primary immunodeficiency disease have been identified, all types share similar symptoms—notably recurring, frequent infections that can be long-lasting and severe. In addition to infections, patients with PI can develop other complications.

The Jeffrey Modell Foundation has identified 10 general warning signs of PI in adults:

• Two or more new ear infections within 1 year
• Two or more new sinus infections within 1 year in the absence of allergy
• One case of pneumonia per year for more than 1 year
• Chronic diarrhea with weight loss
• Recurrent viral infections (colds, herpes, warts, condyloma)
• Recurrent need for intravenous antibiotics to clear infections
• Recurrent deep abscesses of the skin or internal organs
• Persistent thrush or fungal infection on skin or elsewhere
• Infection with normally harmless tuberculosis-like bacteria
• A family history of primary immunodeficiency disease

Two or more of these warning signs could indicate the presence of an underlying PI disease. If you have any of these symptoms, it’s important to talk with your primary care physician. He or she might refer you to a specialist, such as an immunologist.

The Jeffrey Modell Foundation website also lists 10 warning signs of PI in children.

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Diagnosis of primary immunodeficiency

The Immune Deficiency Foundation has estimated that it takes an average of 12.4 years from the time a patient first shows symptoms until he or she is properly diagnosed with a primary immunodeficiency disease. This delay is influenced by the unfamiliarity of primary care physicians and pediatricians with this condition and its characteristic signs and symptoms.

An accurate diagnosis of primary immunodeficiency may also be delayed because the primary symptom of the disorder, a series of infections, can easily be attributed to “ordinary” illness, especially in children. Frequent infections are common among children, even those who would otherwise be classified as “healthy.” In fact, experts estimate that about half of children who see doctors for frequent infections have no underlying condition.

For an adult patient showing signs of PI disease, there are other factors in the diagnosis delay. While severe cases of PI are typically diagnosed in children, symptoms revealing milder forms of PI often do not appear until later in life.

In addition, PI can be hard to diagnose because many patients see multiple specialists to treat various infections. In many instances, there is no single doctor involved in a patient’s total care, making it difficult to notice the pattern of a patient’s infections, which is necessary to quickly reveal the proper diagnosis.

When a doctor does begin to suspect the possibility of a primary immunodeficiency disease, he or she will likely first start by reviewing the patient’s medical and family histories, looking for the patterns that would point to PI.

Usually, PI can be detected using simple blood tests, including a complete blood count (CBC) and quantitative immunoglobulins (a measure of various immunoglobulin levels). Once a PI is detected, more sophisticated tests are required to diagnose the specific type of PI disease.

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Next: Types of primary immunodeficiency disease

Types of PI

More than 150 types of
primary immunodeficiency
have been identified.

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