Epidemiology of rheumatic diseases

In this epidemiological Review, the authors summarize the available evidence relating to the prevalence, incidence, risk factors and mortality associated with the autoimmune disorder Sjögren syndrome, with or without the co-occurrence of other connective tissue diseases.

In this Review, the authors present epidemiological data relating to the idiopathic inflammatory myopathies and summarize the current understanding of the risk factors associated with these conditions, as well as highlighting areas that require further research.

In this Review, the authors summarize and discuss regional differences in the prevalence and incidence of rheumatoid arthritis (RA), and describe temporal trends associated with the disease as well as evidence related to risk factors.

This Review summarizes our understanding of sex- and gender-related differences in psoriatic arthritis, with a focus on disease progression and outcomes, underlying mechanisms and response to therapies.

Erosive hand osteoarthritis is an aggressive condition with poor outcomes. In this Review, the authors describe the clinical features and risk factors associated with erosive hand osteoarthritis, and summarize progress in the areas of biomarkers, imaging, classification criteria and treatment.

Vasculitis, inflammation of the blood vessels, takes many forms and can affect every organ system, potentially causing kidney failure, vision loss and death. This Review describes current knowledge on the global incidence and prevalence patterns for various types of vasculitis.

In this Review, the authors summarize and discuss the existing evidence on the incidence, prevalence and mortality of systemic lupus erythematosus across different world regions, with a focus on studies from the past 5 years.

Immune-related disorders in patients with COVID-19 are increasingly being reported worldwide, with thousands of cases recorded of manifestations that can mimic a broad range of systemic and organ-specific inflammatory and autoimmune diseases.

The prevalence of rheumatic diseases is increasing in African countries, leading to an increased need for specialist rheumatologists and disease-modifying drugs. In this Review, the authors outline what is currently known about the state of rheumatic diseases in Africa.

Fibromyalgia is a complex and common condition characterized by chronic widespread pain and numerous other symptoms. This Review outlines different clinical aspects of fibromyalgia, including the burden, diagnosis and treatment of this condition, and discusses various hypotheses of fibromyalgia etiopathogenesis.

Gout is a chronic crystal deposition disorder in which sustained hyperuricaemia leads to formation and deposition of monosodium urate crystals in the joints. The prevalence and incidence of gout are increasing globally, which may be related to changes in the prevalence of gout risk factors (such as obesity) and comorbidities.

Since the outset of the COVID-19 pandemic, numerous risk factors for severe disease have been identified. Whether patients with rheumatic diseases, especially those receiving DMARDs, are at an increased risk of SARS-CoV-2 infection or severe COVID-19 disease remains unclear, although epidemiological studies are providing some insight.

Immune checkpoint inhibitors, which are used to treat many types of cancer, can cause syndromes similar to rheumatic diseases known as immune-related adverse events (irAEs). In 2020, several studies illustrated the clinical heterogeneity of rheumatic irAEs and highlighted their substantial effect on morbidity and mortality.

Emerging reports show that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection precedes the appearance of various autoimmune and autoinflammatory diseases, including paediatric inflammatory multisystemic syndrome (PIMS) or multisystem inflammatory syndrome in children (MIS-C), thus adding to the growing mystery of this virus and raising questions about the nature of its link with autoimmune and autoinflammatory sequelae.

Epidemiological data on the prevalence and severity of specific manifestations of systemic lupus erythematosus (SLE) among different ethnic groups are now emerging. The use of rigorous epidemiological methods should enable a better understanding of these features of SLE in different ethnic groups, which could influence disease management.