Primary immunodeficiency diseases (PI) are a group of more than 250 rare, chronic disorders in which part of the body’s immune system is missing or functions improperly. While not contagious, these diseases are caused by hereditary or genetic defects. Although some disorders present at birth or early childhood, the disorders can affect anyone, regardless of age or gender. Some affect a single part of the immune system; others may affect one or more system components.

And while the diseases may differ, they all share one common feature: each results from a defect in one of the body’s normal immune system functions. Because one of the most important functions of the normal immune system is to protect us against infection, patients with PI commonly have an increased susceptibility to infection.

The infections may be in the skin, the sinuses, the throat, the ears, the lungs, the brain or spinal cord, or the urinary or intestinal tracts. The increased vulnerability to infection may include repeated infections, infections that won’t clear up, or unusually severe infections. People with PI live their entire lives more susceptible to infections–enduring recurrent health problems and often developing serious and debilitating illnesses. Fortunately, many patients live full and independent lives with proper medical care – early diagnosis and treatment by an allergist/immunologist can prevent ongoing organ damage and death.