Sudden infant death syndrome

Last updated: Saturday, 14, August, 2010
Key InformationAppropriate Tests

Defined as the sudden and unexpected death of an infant under one year of age, with onset of the lethal episode apparently occurring during sleep, that remains unexplained after a thorough investigation including performance of a complete autopsy, and review of the circumstances of death and the clinical history (San Diego 2004).

Predisposing and risk factors include

  • Prone sleeping position
  • Cigarette smoke exposure
  • Overheating
  • Head covering
  • Low socioeconomic status
  • Prematurity
  • Intrauterine growth retardation
  • Maternal drug use
  • Young maternal age
  • Multiparity

Autopsy should be performed by a paediatric or forensic pathologists and should conform to recognised national or international protocols.

Investigations include diagnostic imaging (e.g. a full skeletal survey), toxicology; bacteriologic, virologic, electrolyte and metabolic studies.

Differential Diagnosis for Unexpected Infant and Early Childhood Death

NATURAL

Infection

Cardiovascular: myocarditis, endocarditis, rheumatic fever, aortitis

Respiratory: acute epiglottitis, acute bronchopneumonia

Central nervous system: meningitis, encephalitis, poliomyelitis

Haematologic: malaria, infectious mononucleosis

Gastrointestinal: gastroenteritis, botulism

Genitourinary: pyelonephritis

Generalized: septicaemia, endotoxaemia

Cardiac

Infections

Congential cardiac defects (before and after surgery)

Cardiomyopathies

Valvular abnormalities: aortic stenosis, mitral valve prolapse syndrome, tricuspid valve prolapse

Subaortic stenosis

Tumors

Conduction defects

Miscellaneous: endocardial fibroelastosis

Vascular

Aortic abnormalities: supravalvular stenosis, coarctation, William syndrome, DiGeorge syndrome

Coronary artery abnormalities: anomalous coronary arteries, aplasia/hypoplasia, idiopathic arterial calcinosis, coronary arteritis (Kawasaki disease)

Venous abnormalities: total anomalous pulmonary venous drainage

Vascular malformations

Pulmonary hypertension

Miscellaneous: fibromuscular dysplasia, aortic cystic medial necrosis, Budd-Chiari syndrome, thromboembolism

Respiratory

Infections

Upper airway obstruction

Asthma

Bronchopulmonary dysplasia

Miscellaneous: massive pulmonary haemmorrhage, idiopathic pulmonary haemosiderosis, tension pneumothorax

Central Nervous System

Infections

Epilepsy

Haemorrhage: bleeding diatheses, vascular malformations

Tumours

Metabolic Disorders

Structural Abnormalities

Miscellaneous: Moyamoya disease, fibromuscular dysplasia, Friedreich ataxia, tuberous sclerosis, von Recklinghausen disease, Guillain-Barre syndrome

Haematological

Haemoglobinopathies: sickle cell disease

Malignancies: lymphoma, leukaemia

Bleeding diatheses

Anaemia

Miscellaneous: infections, polycthaemia, splenic disorders

Gastrointestinal

Infections: gastroenteritis

Intestinal obstruction: intussusception, volvulus

Intestinal perforation

Gastro-oesophageal reflux/aspiration

Late-presenting congenital diaphragmatic hernia

Gastrointestinal haemorrhage

Miscellaneous: cystic fibrosis, pancreatitis, anorexia nervosa/malnutrition

Genitourinary

Primary renal disease: pyelonephritis, glomerulonephritis

Urinary tract obstruction

Wilms tumour

Miscellaneous: haemolytic uraemic syndrome

Metabolic

Reye syndrome

Fatty acid oxidation defects: Acyl-CoA dehydrogenase deficiencies (MCAD, LCAD)

Carbohydrate disorders: galactosemia, glycogen storage diseases

Amino acid disorders: homocystinuria

Urea cycle disorders

Organic acid disorders

Endocrine

Congenital adrenal hyperplasia

Diabetes mellitus

Thyroid disease

Miscellaneous

Connective tissue disorders: Marfan syndrome, Ehlers-Danlos syndrome type IV

Chromosomal disorders: trisomy 21

Skeletal disorders: achondroplasia

Dermatological disorders: hypohydrotic ectodermal dysplasia

Muscular conditions: malignant hyperthermia

Immunological conditions: anaphylaxis

UNNATURAL

Accidental

Nonaccidental

References

1. Byard RW, Krous HF, Sudden infant death syndrome - overview and update.  Pediatr Develop Pathol 2003; 6: 112-127

2. Byard RW, Sudden Death in Infancy, Childhood and Adolescence, Cambridge University Press, Cambridge, 2nd Edition, 2004.

3. Byard RW, Krous HF, Sudden natural infant and childhood death.  In: Encyclopedia of Forensic and Legal Medicine, Eds. Payne-James J, Byard RW, Corey T, Henderson C. Elsevier/Academic Press, Amsterdam Vol. 1. pp 382-391, 2005.