A study on the pathogenesis of recurrent parotitis in childhood.

Roentgenologic, histopathologic, electron microscopic, virologic and immunologic studies were performed to investigate the etiologic features of recurrent parotitis in children. When examined sialographically and histopathologically, it was considered that pathologic changes in the parotid gland had developed as latent chronic inflammation with mild glandular destruction long before the disease became manifest clinically with acute exacerbation. Proliferation of the duct epithelium in the regenerative process and increase of intraductal pressure due to obstruction of the salivary outflow were assumed to be the causative factors of dilative changes of the peripheral ductal system. Investigation of complement fixation antibody, hemoagglutination inhibition antibody and neutralization antibody responses to mumps virus showed that onset of the disease was unrelated to mumps infection in the majority of cases. Increase of complement fixation antibody titer to various viruses was observed in many cases during acute exacerbation, and were considered to have brought about secondary ascending bacterial infection of the parotid gland by lowering of the systemic resistance. Comparison of serums IgA, IgG, IgM and salivary IgA in these patients with those of control children did not reveal participation of immunodeficiency in the development of this disease. But judging from the results of the long-term clinical follow-up study it was difficult to disregard the possibility that physiological immaturity of the immune response in young children may play some role in onset and recurrent exacerbation of the disease.