- pylori is a gram negative bacterium which settles in the stomach mucosa and causes inflammation and infection. The infection is strongly related to duodenal ulceration, gastric ulceration, and from time to time gastric carcinoma. There are many studies in which the relationship between the infection of this quite old but current bacterium in stomach /duodenum and different extra-intestinal diseases has been investigated. Among the extra-intestinal diseases, the most common are asthma, rosacea, chronic idiopathic urticarial, atopy, coronary heart disease and migraine. In this review, it has been aimed to study the data obtained from the fields in this field, and the results have been assessed.