Suppressed pediatric asthma hospitalizations during the COVID-19 pandemic in Japan, from a national survey.

BACKGROUND: Acute asthma exacerbation in children is often caused by respiratory infections. In this study, a coordinated national surveillance system for acute asthma hospitalizations and causative respiratory infections was established. We herein report recent trends in pediatric acute asthma hospitalizations since the COVID-19 pandemic in Japan. METHODS: Thirty-three sentinel hospitals in Japan registered all of their hospitalized pediatric asthma patients and their causal pathogens. The changes in acute asthma hospitalization in children before and after the onset of the COVID-19 pandemic and whether or not COVID-19 caused acute asthma exacerbation were investigated. RESULTS: From fiscal years 2010-2019, the median number of acute asthma hospitalizations per year was 3524 (2462-4570), but in fiscal years 2020, 2021, and 2022, the numbers were 820, 1,001, and 1,026, respectively (the fiscal year in Japan is April to March). This decrease was observed in all age groups with the exception of the 3- to 6-year group. SARS-CoV-2 was evaluated in 2094 patients from fiscal years 2020-2022, but the first positive case was not detected until February 2022. Since then, only 36 of them have been identified with SARS-CoV-2, none of which required mechanical ventilation. Influenza, RS virus, and human metapneumovirus infections also decreased in FY 2020. In contrast, 24% of patients had not been receiving long-term control medications before admission despite the severity of bronchial asthma. CONCLUSION: SARS-CoV-2 was hardly detected in children with acute asthma hospitalization during the COVID-19 pandemic. This result indicated that SARS-CoV-2 did not induce acute asthma exacerbation in children. Rather, infection control measures implemented against the pandemic may have consequently reduced other respiratory virus infections and thus acute asthma hospitalizations during this period. However, the fact that many hospitalized patients have not been receiving appropriate long-term control medications is a major problem that should be addressed.

Anaphylaxis to Carboxymethylcellulose: Add Food Additives to the List of Elicitors.

A 14-year-old girl developed 4 episodes of anaphylaxis of unknown etiology, which required intramuscular adrenaline administration each time. She had eaten pizza and a cheeseburger immediately before the first 2 episodes, respectively, but had not eaten anything for several hours before the last 2 episodes. It turned out that she had eaten the same ice lolly 4 hours before the first 3 episodes and a Café au lait Swirkle (a half-frozen beverage) 4 hours before the last episode. We detected carboxymethylcellulose sodium as the only common ingredient in all anaphylactic episodes. Skin prick tests were positive for carboxymethylcellulose solution and carboxymethylcellulose-containing food products. We obtained a custom-made carboxymethylcellulose sodium-free ice lolly from the manufacturer and confirmed that it did not induce anaphylactic reactions by a challenge test. Carboxymethylcellulose, an anionic water-soluble polymer derived from native cellulose, is considered to be unabsorbable from the human gut and has been widely and increasingly used in pharmaceutical preparations, cosmetics, and food. This article is the first report of anaphylaxis caused by carboxymethylcellulose-containing foods, whereas anaphylaxis to carboxymethylcellulose has been rarely associated with carboxymethylcellulose-containing pharmaceuticals. Although the exact mechanisms underlying the induction of late-onset anaphylaxis by carboxymethylcellulose remain unclear, a small minority of cellulose-digesting microbial flora in the human colon and contamination of food products with carboxymethylcellulose of low molecular weight might be involved. The induction of recurrent anaphylaxis by various products should be a clue that prompts physicians to suspect food additives as a cause for anaphylaxis.

A case of mixed connective tissue disease complicated with hypertrophic obstructive cardiomyopathy.

A 54-year-old female was diagnosed as mixed connective tissue disease (MCTD) complicated with secondary Sjögren's syndrome. Although she had no dyspnea on exertion, the chest X-ray showed cardiomegaly with interstitial pneumonia. The echocardiogram demonstrated asymmetric hypertrophy of the interventricular septum. Diagnosis of hypertrophic obstructive cardiomyopathy (HOCM) was confirmed by left ventriculography and myocardial biopsy. She was treated with prednisolone, resulting in improvement of swollen hand, elevated muscle enzymes and interstitial pneumonia. A rare complication of HOCM with MCTD was described.