About 2500 years ago, gout was observed by Hippocrates and many people suffered severe pain and deformity. Lifestyle and diet play a significant role in gout and serum uric acid levels. Epidemiological and research studies have supported this evidence. Many recommendations and guidelines from different parts of the world mention the impact of diet on gout. Recently, new research has shown associations between vitamin C, alcohol, coffee, tea, milk and yogurt with uric acid and the risk of gout. Our review summarizes recently published research regarding dietary impact on the risk of gout and serum uric acid levels.

Background The aim of this systematic literature review was to comprehensively describe the anatomical pathology of tissues affected by gout. Methods We searched PubMed, The Cochrane Library, Excerpta Medica Database (EMBASE), and Web of Science Core Collection for all English language articles published before March 2018. Articles were included if they described the microscopic or macroscopic appearances of gout in human tissue. Results Four hundred and seventeen articles met inclusion criteria and were included in the review. Articles describing the anatomical pathology of gout in musculoskeletal structures, including bone, tendon and ligaments, synovium and cartilage, were most common. Articles describing skin and kidney pathology in gout were also common, with pathology in other sites such as visceral organs less common. At all sites, monosodium urate crystal deposition was reported, and the tophus was also described within many different tissues. During a gout flare, diffuse acute neutrophilic synovial inflammation was evident. The tophus was described as an organised chronic giant cell granulomatous structure consisting of monosodium urate crystals, innate and adaptive immune cells, and fibrovascular tissue. Conclusions Consistent with the clinical presentation of gout, most studies describing the anatomical pathology of gout report involvement of musculoskeletal structures, with monosodium urate crystal deposition and tophus the most common lesions described. This review details the anatomical pathology features of gout at affected sites. Electronic supplementary material The online version of this article (10.1186/s12891-019-2519-y) contains supplementary material, which is available to authorized users.

BackgroundIt is currently unknown whether bone erosion in gout occurs through an ‘inside-out’ mechanism due to direct intra-osseous crystal deposition or through an ‘outside-in’ mechanism from the surface of bone. The aim of this study was to examine the mechanism (‘outside-in’ vs. ‘inside-out’) of monosodium urate (MSU) crystal deposition in bone erosion in gout. Specifically, we used three-dimensional dual-energy computed tomography (DECT) to analyse the positional relationship between bone and MSU crystal deposition in tophaceous gout, and to determine whether intra-osseous crystal deposition occurs in the absence of erosion.MethodsOne hundred forty-four participants with gout and at least one palpable tophus had a DECT scan of both feet. Two readers independently scored all metatarsal heads (1433 bones available for scoring). For bones in contact with urate, the bone was scored for whether urate was present within an erosion, on the surface of bone or within bone only (true intra-osseous deposit). Data were analysed using generalised estimating equations.ResultsUrate in contact with bone was present in 370 (54.3 %) of 681 joints with urate deposition. For those bones in contact with urate, deposition was present on the surface of bone in 143 (38.6 %) of 370 joints and within erosion in 227 (61.4 %) of 370. True intra-osseous urate deposition was not observed at any site (p < 0.0001). For all bones with apparent intra-osseous deposition in one plane, examination in other planes revealed urate deposition within an en face erosion.ConclusionsIn tophaceous gout, MSU crystal deposition is present within the joint, on the bone surface and within bone erosion, but it is not observed within bone in the absence of a cortical break. These data support the concept that MSU crystals deposit outside bone and contribute to bone erosion through an ‘outside-in’ mechanism.