title: Lactase deficiency: a potential novel aetiological factor in chronic pruritus of unknown origin.
abstract: Chronic pruritus, which is associated with a wide variety of underlying diseases, represents a challenge in diagnostics and treatment in dermatology and general medicine. The cause of pruritus remains unknown in up to 45% of patients. In this study, 718 patients with chronic pruritus were analysed concerning lactase deficiency, demographic data, aetiology, duration and intensity of pruritus. A total of 154 patients were tested positive for lactase deficiency and 38.3% showed a significant anti-pruritic response to a lactose-free diet (minimum 4 weeks). The best results were observed in patients with pruritus of mixed or unknown origin (n = 91; 64% response). Age, sex, localization or duration had no significant influence on the anti-pruritic effect of a lactose-free diet. Lactase deficiency might be an independent causal factor in the elicitation of chronic pruritus. Thus, screening for lactase deficiency represents a rational step in the diagnostic work-up of chronic pruritus. In case of a positive test result, a lactose-free diet offers a low-cost, efficient and specific therapy in patients with chronic pruritus.
authors: Department of Dermatology and Competence Center Chronic Pruritus, University Hospital, DE-48149 Münster, Germany. sonja.grundmann@ukmuenster.de
authors: Sonja A
authors: SA
authors: Grundmann
authors: Ewelina
authors: E
authors: Stratmann
authors: Randolf
authors: R
authors: Brehler
authors: Thomas A
authors: TA
authors: Luger
authors: Sonja
authors: S
authors: Ständer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D005260:Female; D006801:Humans; D043322:Lactase / Q000097:blood / Q000172:deficiency*; D007785:Lactose / Q000378:metabolism; D007787:Lactose Intolerance / Q000150:complications*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011537:Pruritus / Q000097:blood / Q000178:diet therapy* / Q000209:etiology*; D012307:Risk Factors; D012720:Severity of Illness Index; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D043322:Lactase; D007785:Lactose