Cough, coronavirus disease 2019, the vaccines, and allergy.

Cough is a physiological defense mechanism, and one of the most common symptoms for seeking a medical service. The common etiology of chronic cough could be related with allergic diseases such as asthma, upper airway cough syndrome due to allergic rhinitis, non-allergic rhinitis, or chronic rhinosinusitis, and eosinophilic bronchitis. In this issue, Won and Song [1] features the impact and disease burden of chronic cough. Readers will enjoy the journey composed of the physiologic and pathologic cough, cough duration, cough hypersensitivity syndrome, its impact, and patients' experience. Because cough is one of the most common symptoms of coronavirus disease 2019 (COVID-19), people with chronic cough can experience more isolation from their colleagues, friends and even family. Readers will also find out the voices of patients with chronic cough in the time of COVID-19.

In my daily clinic, many patients with allergic rhinitis or seasonal asthma report that their symptoms got much better after wearing masks in the time of COVID-19. Readers will find an interesting article from Turkey that spending less time outdoors during the lockdown and wearing masks showed less allergic symptoms in 2020 [2].

After the first vaccination against COVID-19 starting from United Kingdom, to vaccinate the world against COVID-19 has kicked off. Anaphylaxis as an adverse event after immunization (AEFI) is uncommon, occurring usually at a rate of less than 1 per million doses for most vaccines [3]. The incidence of anaphylaxis as an AEFI after COVID-19 vaccination has been reported (e.g., 4.7 per million doses following Pfizer-BioNTech vaccine, 2.5 per million doses following Moderna vaccine in the United States) [4]. Potential allergens have been proposed as polyethylene glycol (PEG) in mRNA vaccines such as Pfizer-BioNTech and Moderna vaccines, and polysorbate 80 in other vaccines such as Oxford/AstraZeneca ChAdOx1 and Johnson & Johnson's Janssen vaccines [3]. International organizations such as Asia Pacific Association of Allergy, Asthma, and Clinical Immunology (APAAACI) and World Allergy Organization have published the statements or recommendations on the COVID-19 vaccine associated anaphylaxis [35]. Recent APAAACI Allergy Week (April 12–18, 2021) was a great success with theme of “COVID-19: Allergies and Vaccines – Understanding the Facts & Myths.” All the member societies of APAAACI have been involved and the webinar on COVID-19 vaccine and allergy on April 12 was a highlight [6]. The risk stratification is important and healthcare workers must follow local authorizations and policy in terms of indications and contraindications for COVID-19 vaccines, which will be continuously updated. Most of the guidelines recommend that any individual with an immediate or severe allergic reaction to the vaccine or any component of the vaccine (e.g., PEG or polysorbate) should see an allergist before receiving the vaccine. Proposals on skin testing with PEG or polysorbate have been published although the positive and negative predictive value of the skin testing are unknown [7]. Skin test with the vaccines is not generally recommended because of the availability and lack of data on the nonirritating concentration, and the positive and negative predictive value. In this issue, Vieira et al. [8] presents their experience on skin testing with Pfizer-BioNTech vaccine and PEG 2000.

Aspirin is useful for the secondary prevention of cardiovascular events in individuals with atherosclerotic cardiovascular disease, providing reduction in the risk of subsequent myocardial infarction, stroke, and vascular death [9]. In patients with nonsteroidal anti-inflammatory drugs hypersensitivity, allergists can perform aspirin desensitization that aspirin therapy could be initiated and continued. In this issue, Cheong et al. [9] presents the patient characterization and predictors of aspirin desensitization response with 214 patients from Singapore.

Readers will also find interesting cases of goat's milk allergy in a family following household sensitization to goat's milk soap and of anaphylaxis due to potato starch possibly caused by percutaneous sensitization [1011].

Thank you very much for your support on Asia Pacific Allergy. Please also join World Allergy Week 2021 by the World Allergy Organization (June 13–19, 2021) with the theme of “Anaphylaxis: Be aware. Be prepared. Save lives.” The last year's theme was “Allergy care does not stop with COVID-19” that both of the themes are important especially in the time of COVID-19 and the vaccination [1213].