An immunodeficiency disorder describes any condition that weakens the body's ability to fight off infection.
An immunodeficiency disorder can be one that is present at birth, such as severe combined immunodeficiency (SCID). It may also be acquired, such as acquired immunodeficiency syndrome (AIDS). A person who has one of these disorders is prone to develop a variety of infections, some of them quite severe.
The symptoms present depend on the type of immunodeficiency disorder. The one thing all such disorders have in common is frequent infections. These infections may occur anywhere in the body.
The disorder may be genetic or acquired. AIDS, for example, is caused by a the human immunodeficiency virus (HIV), which can be spread by transfusion of contaminated blood, sexually, or by using contaminated needles. The risk of acquiring AIDS following blood transfusion has decreased to nearly zero due to routine testing of all blood products.
Most of these disorders cannot be prevented. AIDS can be prevented by avoiding unprotected sex and by not sharing needles. If a person has sex, condoms can reduce, but not eliminate, the risk of catching HIV.
A history of repeated or unusual infections suggest one of these disorders. A healthcare professional may do various tests, including blood tests and special x-rays, to search for a cause of a weakened immune system.
Almost any infection may lead to death if the immune system cannot fight it off.
A person with an immunodeficiency disorder may have infections that can be spread to other people. HIV itself can be transmitted sexually or by sharing injection equipment.
Aggressive antibiotic treatment is needed to quell most infections. In some cases, there is no treatment for the underlying disorder. Some cases of SCID have been successfully treated with bone marrow transplantation from a family member.
Antibiotics can cause allergic reactions and stomach upset. Other side effects depend on the antibiotic used. Bone marrow transplantation is a complex and risky procedure that can have many complications including overwhelming infection and bleeding.
Most of these disorders persist for the long-term, sometimes for life. Repeated treatment for infection and monitoring are needed.
A person who has one of these disorders should see a healthcare professional at the first sign of a possible infection. The type of monitoring done depends on the specific disorder.
Harrison's Principles of Internal Medicine, 1998, Fauci et al.
