Immunodeficiency Diseases Defined

Primary Immunodeficiency Diseases (PIDD) are a group of more than 300 diseases. These conditions are due to defects in the body's defenses (immune system).

In most cases, PIDD are associated with acute or recurrent infections, depending on the portion of the immune system affected. Most PIDD are inherited in our genes, so they are present at birth, but they often do not become apparent or diagnosed until late in childhood, or even in adult life. It often takes time for a pattern of recurrent infections or other symptoms to develop before a PIDD is suspected. There are more than 100 different genetic causes of PIDD.

Signs that you or your child might have a PIDD include:
• Recurrent, unusual or difficult to treat infections
• Poor growth or loss of weight
• Recurrent pneumonia, ear infections or sinusitis
• Multiple courses of antibiotics or IV antibiotics necessary to clear infections
• Recurrent deep abscesses of the organs or skin
• A family history of PIDD
• Swollen lymph glands or an enlarged spleen

Some PIDD can mimic other conditions including allergy, asthma or eczema and vice versa, so evaluation by an allergist / immunologist is extremely helpful for reaching a diagnosis and developing an effective treatment plan.

Learn more about PIDD symptoms, diagnosis, treatment and management.

Video: What is a Primary Immunodeficiency Disease (PIDD)

The AAAAI's Find an Allergist / Immunologist service is a trusted resource to help you find a specialist close to home.

The Immune Deficiency Foundation explains the types of PIDDS here.