title: [Primary immunodeficiencies in seriously ill children: Report of 3 clinical cases].
abstract: Primary immunodeficiency diseases (PID) are congenital disorders secondary to an impaired immune response. Infections, autoimmune disorders, atopy, and lymphoproliferative syndromes are commonly associated with this disorder.
  
  
  
  To present and discuss 3 infants diagnosed with PID.
  
  
  
  The cases are presented of three patients with PID diagnosed during their first admission to a Paediatric Intensive Critical Care Unit. The first patient, a 4-month-old infant affected by a severe pneumonia, and was diagnosed as a Severe Combined Immunodeficiency Disease. The second patient was an 8-month-old infant with Candida lusitaniae mesenteric adenitis, and diagnosed with a Chronic Granulomatous Disease. The last patient, a 6-month-old infant presented with ecthyma gangrenosum and X-linked agammaglobulinaemia.
  
  
  
  PID should be suspected when an infectious disease does not responde to the appropriate therapy within the expected period. An update of each disease is presented.
authors.affiliation: Unidad de Paciente Crítico Pediátrico, Clínica Santa María, Santiago, Chile.
authors.forename: Leticia
authors.initials: L
authors.lastname: Yáñez
authors.affiliation: Unidad de Paciente Crítico Pediátrico, Clínica Santa María, Santiago, Chile.
authors.forename: Pamela
authors.initials: P
authors.lastname: Lama
authors.affiliation: Unidad de Paciente Crítico Pediátrico, Clínica Santa María, Santiago, Chile.
authors.forename: Carolina
authors.initials: C
authors.lastname: Rivacoba
authors.affiliation: Unidad de Paciente Crítico Pediátrico, Clínica Santa María, Santiago, Chile.
authors.forename: Juanita
authors.initials: J
authors.lastname: Zamorano
authors.affiliation: Unidad de Paciente Crítico Pediátrico, Clínica Santa María, Santiago, Chile.
authors.forename: María Angélica
authors.initials: MA
authors.lastname: Marinovic
mesh_terms: D000361:Agammaglobulinemia / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology; D040181:Genetic Diseases, X-Linked / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology; D006105:Granulomatous Disease, Chronic / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology; D007223:Infant; D015278:Intensive Care Units, Pediatric; D008297:Male; D012720:Severity of Illness Index