Relationship between headache and mucosal mast cells in pediatric Helicobacter pylori-negative functional dyspepsia

Background: Although many patients with functional dyspepsia experience headache concurrently with dyspeptic symptoms, studies suggesting mechanisms underlying this phenomenon are limited. Herein, we explore the relationship between gastrointestinal inflammatory cells and presence of headache associated with dyspeptic symptoms in children with Helicobacter pylori-negative functional dyspepsia. Methods: Fifty-six patients with H. pylori-negative functional dyspepsia underwent upper endoscopy with biopsy to investigate recurrent epigastric pain or discomfort. Patients were divided into two groups according to self-reported presence of headache associated with dyspeptic symptoms. Inflammatory cells including mast cells, and enteroendocrine cells in the gastroduodenal mucosa were evaluated. Associations between headache presence and cellular changes in the gastroduodenal mucosa were examined. Results: Headache was not associated with the grade of lymphocytes, neutrophil infiltration, or enteroendocrine cell density in the gastroduedenal mucosa. However, headache was significantly associated with high mast cell density in the body (27.81 +/- 8.71 vs. 20.30 +/- 8.16, p<0.01) and duodenum (23.16 +/- 10.40 vs. 14.84 +/- 5.88, p<0.01). Conclusions: Presence of headache associated with dyspeptic symptoms is strongly related to mucosal mast cell density in pediatric patients with H. pylori-negative functional dyspepsia. Thus, our results may help clinicians understand and treat headache during dyspeptic symptoms in such pediatric patients.