Immunodeficiency in a Child Presenting with Ecthyma Gangrenosum and Normal Immunoglobulin Levels

Primary immunodeficiency diseases (PID) are genetic defects of the immune system that result in chronic, serious, and often life-threatening infections if not diagnosed and treated appropriately. Antibody deficiency is the most common PID, accounting for 50% of all cases. X-linked agammaglobulinemia (XLA) with Bruton tyrosine kinase (BTK) deficiency is the most common antibody deficiency. XLA presenting with ecthyma gangrenosum is rare and has only been noted in a few case reports. Here, we present a one-year-old Filipino male who was previously well until admission at 10 months of age for a first episode of severe pneumonia with concomitant ecthyma gangrenosum. No similar case has been reported in the Philippines to date. This patient also had normal immunoglobulin levels and a reactive antibody response to a vaccine. His older brother died at 1 year and 4 months of age due to pneumonia and sepsis, and his stepbrother also died at 1 year of age due to pneumonia. XLA may be suspected in patients with ecthyma gangrenosum, especially in the presence of a strong family history of early deaths among males on the maternal side, despite normal serum immunoglobulin levels. It is therefore imperative to include XLA in the differential diagnosis of a child with increased susceptibility to infection and neutropenia.