Infections of the upper respiratory tract in cases of sudden infant death.

The nasal cavities were examined in 56 cases of sudden infant death syndrome (SIDS) and 26 control cases and the following criteria were compared: inflammatory infiltration of the nasal mucosa (SIDS 59%--controls 65%; P = 0.577), diapedesis of inflammatory cells (SIDS 38%--controls 42%; P = 0.678), epithelial desquamation (SIDS 62%--controls 85%; P = 0.043); hyperemia (SIDS 66%--controls 65%; P = 0.951) and hypersecretion of the seromucous glands (SIDS 55%--controls 69%; P = 0.233). Only epithelial desquamation was found significantly more often in the controls than in SIDS cases, but these alterations are unspecific and are influenced by the postmortem interval. The intensity of rhinitis was not different between the SIDS and control groups. The frequency of rhinitis is therefore not specific for the sudden infant death syndrome, and seems to be merely a result of the high incidence of upper respiratory tract infections in this age group. We speculate, however, that infections of the nose in conjunction with other factors, such as prone position, covering of the head, hyperthermia, parental smoking and immaturity of the central nervous system, could play a role in the pathogenesis of the sudden infant death syndrome.