HRQoL questionnaire evaluation in lactose intolerant patients with adverse reactions to foods.

The occurrence of patients with gastrointestinal symptoms attributed either to food allergy or intolerance has significantly increased. Nevertheless, an accurate and detailed case history, a systematic evaluation and the outcomes of specific allergy tests to identify the offending foods, including "in vivo" and "in vitro" allergy tests, are often negative for food allergy and may indicate a lactose intolerance, which is a recurrent condition affecting about 50% of adults. The aims of our study were the following: (1) What is the real incidence of the food hypersensitivity and the primary lactose intolerance in patients with gastrointestinal symptoms, initially referred to allergy or food intolerance? (2) Does lactose intolerance affect the quality of life and compliance to the therapy program? We investigated 262 consecutive patients, 72 men and 190 women. An accurate and detailed history and clinical examination were completed to investigate the offending foods. The evaluation in each patient included: allergy tests, lactose H2 breath test (LHBT) and the HRQoL questionnaire. Five years after the diagnosis of lactose intolerance, a questionnaire on the persistence of gastrointestinal symptoms after lactose ingestion and the diet compliance was distributed. Our results demonstrate an high prevalence of lactose intolerance, more frequent in women; in these patients, bloating and diarrhea are the most reported symptoms. We observe only a significant positive correlation between adverse drug reaction (ADR) and LHBT+ patients, but not an augmented prevalence of food allergy and a negative impact on the HRQoL questionnaire of lactose intolerance.