Child neglect followed by marked thymic involution and fatal systemic pseudomonas infection

The case of a 9-month-old baby girl who failed to develop normally due to nutritional neglect and secondary immunodeficiency characterized by marked thymic involution is reported. The child died of systemic Pseudomonas aeruginosa (P. aeruginosa) infection manifested in pneumonia, lung abscesses, bacterial endocarditis and ecthyma gangrenosum. At autopsy the child was 64 cm in height (normal for a 4- to 5-month-old child) and 5.1 kg in weight (normal for a 2- to 3-month-old child). Multiple gangrenous ecthymas, consisting of deep ulcers, induration and inflammation, were observed in the skin over the entire body. The lungs showed hemorrhagic pneumonia, multiple lung abscesses, and necrotizing arteritis in the abscesses and surrounding areas. The thymus weighed 2.3 g and showed marked involution. Histological examination showed so-called nutritional thymectomy characterized by severe cortical atrophy and clustering, cystic dilation and amorphous changes of the Hassall's corpuscles. In the heart, dark brown verrucae were present at the attachment sites of the tendinous cords of the papillary muscle in the anterior and posterior cusps of the mitral valve, suggesting infectious endocarditis. Bacteriological examination demonstrated P. aeruginosa in the ecthymas, lung abscesses and blood. As primary immunodeficiency was considered unlikely, immunodeficiency secondary to thymic involution following malnutrition seemed to have led to a fatal systemic infection with P. aeruginosa, whose virulence is generally weak. This suggests a close association of the development of such infection and immunodeficiency with child neglect.