[HOW TO APPROACH A PATIENT WITH SUSPECTED IMMUNODEFICIENCY]

Area of Science:

• Immunology
• Clinical Medicine

Background:

• The immune system protects against pathogens, autoimmunity, and malignancy.
• Primary immunodeficiency diseases (PIDs) are more prevalent than commonly perceived and can manifest at any life stage.
• Immune system insults, whether primary or secondary, increase susceptibility to infections, autoimmune conditions, and cancers.

Purpose of the Study:

• To review primary and secondary immune deficiency diseases.
• To highlight key "red flags" indicative of immunodeficiency states.
• To propose a structured diagnostic workup for primary care physicians and clinical immunology specialists.

Main Methods:

• Literature review of primary and secondary immune deficiency diseases.
• Identification and summarization of clinical "red flags" for immunodeficiency.
• Development of a stepwise diagnostic approach for suspected cases.

Main Results:

• PIDs are more common than expected and occur across all ages.
• Recurrent or invasive infections, atypical pathogens, and poor treatment response are significant indicators.
• Failure to thrive, chronic diarrhea, fungal infections, unexplained rashes, and family history are crucial "red flags".

Conclusions:

• A structured approach is essential for evaluating patients with suspected immunodeficiency.
• Early diagnosis and treatment are facilitated by understanding immune system function and utilizing advanced diagnostic tools.
• Recognizing "red flags" aids primary care physicians and specialists in timely patient management.