Extrapulmonary manifestations and complications of severe acute respiratory syndrome coronavirus-2 infection: a systematic review

INTRODUCTION@#We aimed to describe the extrapulmonary manifestations of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, including their frequency, onset with respect to respiratory symptoms, pathogenesis and association with disease severity.@*METHODS@#We searched the MEDLINE and Embase databases for SARS-CoV-2-related studies. Meta-analysis, observational studies, case series and case reports published in English or Chinese between 1 January 2020 and 1 May 2020 were included. Reports with only paediatric or obstetric cases were excluded.@*RESULTS@#169 articles were included. Early manifestations (preceding respiratory symptoms until Day 6 of onset) included olfactory and gustatory disturbance (self-reported in up to 68% and 85% of cases, respectively), gastrointestinal symptoms (up to 65.9%) and rash (up to 20.4%). From Day 7 onwards, hypercytokinaemia, paralleled multi-organ complications including acute cardiac injury (pooled incidence of 17.7% in 1,412 patients, mostly with severe disease and 17.4% mortality), kidney and liver injury (up to 17% and 33%, respectively) and thrombocytopenia (up to 30%). Hypercoagulability resulted in venous thromboembolic events in up to 31% of all patients. Uncommon disease presentation and complications comprised Guillain-Barré syndrome, rhabdomyolysis, otitis media, meningoencephalitis and spontaneous pneumomediastinum.@*CONCLUSION@#Although the systemic manifestations of SARS-CoV-2 infection are variegated, they are deeply interwoven by shared mechanisms. Two phases of extrapulmonary disease were identified: (a) an early phase with possible gastrointestinal, ocular and cutaneous involvement; and (b) a late phase characterised by multiorgan dysfunction and clinical deterioration. A clear, multidisciplinary consensus to define and approach thromboinflammation and cytokine release syndrome in SARS-CoV-2 is needed.

Food allergy in Singapore: opening a new chapter

With the exception of shellfish, the overall food allergy rates in Singapore have not reached the epidemic proportions of the West. The rates of egg, milk and fish allergies remain low. However, the patterns of some food allergies in Singapore have changed over the last decade. For example, peanut allergy, once rare in Singapore, is now the most common cause of anaphylaxis in children. Studies analysing lifestyle practices, particularly with respect to prevention of food allergy, are necessary in order for practitioners to understand global differences and maintain this low prevalence.

Food allergy in Asia: how does it compare?

Asia is a populous and diverse region and potentially an important source of information on food allergy. This review aims to summarize the current literature on food allergy from this region, comparing it with western populations. A PubMed search using strategies "Food allergy AND Asia", "Food anaphylaxis AND Asia", and "Food allergy AND each Asian country" was made. Overall, 53 articles, published between 2005 and 2012, mainly written in English were reviewed. The overall prevalence of food allergy in Asia is somewhat comparable to the West. However, the types of food allergy differ in order of relevance. Shellfish is the most common food allergen from Asia, in part due to the abundance of seafood in this region. It is unique as symptoms vary widely from oral symptoms to anaphylaxis for the same individual. Data suggest that house dust mite tropomysin may be a primary sensitizer. In contrast, peanut prevalence in Asia is extremely low compared to the West for reasons not yet understood. Among young children and infants, egg and cow's milk allergy are the two most common food allergies, with prevalence data comparable to western populations. Differences also exist within Asia. Wheat allergy, though uncommon in most Asian countries, is the most common cause of anaphylaxis in Japan and Korea, and is increasing in Thailand. Current food allergy data from Asia highlights important differences between East and West, and within the Asian region. Further work is needed to provide insight on the environmental risk factors accounting for these differences.