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Chronic granulomatous disease — RACP Paediatrics MCQ

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HardIDChronic granulomatous diseaseRACP Paediatrics

A 3-year-old boy has recurrent deep-seated abscesses (liver, lung, lymph node) caused by catalase-positive organisms (Staphylococcus aureus, Aspergillus, Serratia). Dihydrorhodamine (DHR) flow cytometry test is abnormal. What is the most likely diagnosis?

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Correct answer: B — Chronic granulomatous disease

Recurrent infections with catalase-positive organisms (S. aureus, Aspergillus, Serratia, Burkholderia) forming deep abscesses is characteristic of chronic granulomatous disease (CGD). CGD is caused by defective NADPH oxidase in phagocytes. DHR flow cytometry or nitroblue tetrazolium (NBT) test confirms the diagnosis. Prophylactic co-trimoxazole and itraconazole reduce infection frequency.

Reference: RCH Melbourne – 2023 – Immunodeficiency CPG; RACP Paediatric Curriculum – Immunology