• Repeated invasive infections (two or more cases of pneumonia, recurrent septicemia, abscesses, meningitis).¹
  • Infections with unusual or opportunistic pathogens (PJP).¹
  • Poor response to prolonged or multiple antibiotic therapies.¹
  • Chronic diarrhea with or without evidence of colitis.¹
  • Chronic failure to gain weight and grow.²
  • Persistent (or recurrent) unusual (atypical) or resistant to treatment oral lesions (thrush) or skin rash (erythroderma, telangiectasias, recurrent pustules/nodules/plaques).¹
  • Structurally abnormal hair (kinky, silvery) nails (dystrophic), or teeth (pointy).²
  • Low serum IgG, chronic lymphopenia, neutropenia, or thrombocytopenia.¹
  • Absent lymph nodes and tonsils or chronic enlargement of lymphoid tissues.¹
  • A family history of Primary Immunodeficiency, autoimmunity, or leukemia/lymphoma. ¹


¹ All age groups

² Infancy and childhood

There are more than 430 recognized genetic defects and disorders of the immune system as Primary Immunodeficiency. Approximately one in every 1,200 individuals is affected by this disease, emphasizing the importance of early diagnosis and treatment to save lives. Timely treatment can enhance or prevent long-term organ damage. Each Red Flag, when observed alone, should prompt healthcare providers to consider the possibility of Primary Immunodeficiency, necessitating further testing and investigation.

Note: Two or more Red Flags should trigger an urgent referral to an Immunologist.

Written and approved by the Scientific Director and the Medical Advisory Board © 2014 Immunodeficiency Canada