Fifteen-minute consultation: The child with an incidental finding of low IgA.

Low or absent immunoglobulin A (IgA) levels are frequently found in children in whom immunodeficiency is not suspected. IgA deficiency is the most common primary immunodeficiency disorder in the UK affecting approximately 1 in 600 people. Isolated IgA deficiency is often identified coincidentally when investigating a child for conditions such as coeliac disease. The aim of this article is to provide a structured approach to the history, investigation and management of an isolated IgA deficiency.