Allergy and Immunology

Allergic disorders

Immunology Overview

A brief overview of how the immune system defends the host, comparing innate and adaptive immunity. It then covers the 10 warning signs of primary immunodeficiency, the main ways immunodeficiencies are classified, and which infections point to a B-cell, T-cell, phagocyte or complement defect, ending with the first-line work-up.

Disorders of B-cell Lymphocytes

Covers the four primary B-cell (antibody) deficiencies: X-linked agammaglobulinemia, common variable immunodeficiency, selective IgA deficiency and hyper-IgM syndrome. One master table shows how B-cell count and the immunoglobulin pattern separate them. For each disorder it gives the mechanism, presentation, stepwise workup and treatment, with the classic exam traps on live vaccines, IVIG and transfusion.

Disorders of T-cell Lymphocytes

Covers the T-cell and combined immunodeficiencies that present in early infancy: DiGeorge syndrome, severe combined immunodeficiency, Wiskott-Aldrich syndrome and ataxia-telangiectasia. One comparison table sets out how T cells, B cells, immunoglobulins and platelets differ, and each disorder gets its genetics, classic presentation, stepwise workup and treatment. The exam traps on irradiated blood, live vaccines, small platelets and radiation are flagged.