Narrative review discusses link between diamine oxidase deficiency and fibromyalgia pathophysiology

This narrative review explores the potential role of histamine intolerance and diamine oxidase (DAO) deficiency in the pathophysiology of fibromyalgia. The authors synthesize evidence regarding the prevalence of genetic variants associated with DAO deficiency, noting a higher prevalence of 74.5% in fibromyalgia patients compared to 66% in the general population (p = 0.014).

The review highlights correlations between symptom severity and the accumulation of these genetic variants. Specifically, the authors note an approximately 7-point increase in the Fibromyalgia Impact Questionnaire (FIQ) per allele. Regarding interventions, the review presents data where DAO supplementation resulted in an 8.4 point decrease on the Pain Catastrophizing Scale, compared to a 2.1 point change in the placebo group. Additionally, the DAO supplementation group showed a 12.3 point improvement in FIQ scores, versus a 4.6 point improvement in the placebo group.

While the evidence suggests that histamine intolerance, mediated by DAO deficiency, may contribute to fibromyalgia in certain subgroups, the review focuses on emerging associations. The authors suggest that these mechanisms may play a role in the disease process, but the clinical implications remain an area for further study.