Diagnosis of CID

The most important clue is often the family history. If there is another member of the family who has had unusual infections, autoimmune disease or cancers at a young age, then this can highlight an inherited problem. If parents are blood relatives, the risk of inherited diseases, including CID, is increased in their
offspring.

CID may show up in the form of repeated and/or severe infections, especially when accompanied by poor growth or an autoimmune condition (such as anaemia or a bleeding tendency caused by antibodies against blood cells). Occasionally there may be clues to a certain type of CID outside the immune system; for example, problems with the skin, bones, teeth or heart. As a result, children with CID are often in contact with child health services from a young age.

If immunodeficiency is suspected, an immunologist will be consulted and referral made to the regional or national specialist immunology centre. Special investigations will be arranged. Some of the tests will have to be sent away and
the results may take a long time to come back. Accurate diagnosis of infection and other complications is all part of building up a full picture. Often, genetic testing is needed to be sure of the diagnosis.

Reviewed November 2017