RESUMO
To determine the presence of H. pylori and, if detected, its potential prevalence in the etiology of recurrent aphthous ulcers [RAS], confined to mucosa-associated lymphoid tissues [MALTs] of the pharynx. A prospective, controlled clinical trial. The study population comprised 146 patients with recurrent multiple aphous ulcers of the oral cavity and pharynx, and 20 normal subjects, that were used as controls. Patients were assigned to [Group A, n=58] in whom the ulcers were strictly limited to the lymphoid tissues, or [Group B, n=88] in whom the ulcers were randomly distributed in the oral cavity and pharynx. H. pylori DNA was extracted from 3-mm-diameter tissue samples and PCR amplifications were performed for the 16S ribosomal RNA [rRNA] gene. In examining all the samples; Group A, 39 [68%] patients were shown to be positive for H. pylori DNA, while in Group B, 9 [10%] patients were shown to be positive for H. pylori DNA, but it was not detected in any of the 20 control samples [Chi test, P<0.001]. Our results support a possible etiological role for H. pylori in recurrent aphthous ulcerations with a characteristic distribution and affinity to mucosa-associated lymphoid tissues of the pharynx