Everything a general paediatrician needs to know about primary immunodeficiencies.

Primary immunodeficiencies (PID) are a heterogenous group of inherited diseases, arising from inborn errors of immunity. Although typically managed by specialist immunologists, general paediatricians are often the first point of referral for patients with clinical pictures that may be presentations of PID. Recurrent, severe or atypical infections are common, but autoimmunity, aberrant inflammation and malignancy may also occur. PID may occur with or without other syndromic features. Early diagnosis and implementation of treatment are important, particularly if curative bone marrow transplant is a possible treatment modality. Therefore, knowledge of PID phenotypes, recognition of presentations and an approach to investigation are essential. Advances in genetic testing have greatly enhanced the ability to diagnose PID and their underlying genetic defects.