Type 2-immunity represents the typical adaptive response to allergen exposure in atopic individuals. It mainly involves Th2 cells and immunoglobulin E, as the main orchestrators of type 2-inflammation. Recently, it has been highlighted that allergens may be responsible for a Th2 response beside specific IgE activation and that a number of other environmental stimuli, such as viruses and pollutants, can trigger the same pattern of inflammation beyond atopy. Emerging data sustain a substantial role of the so-called epithelial dysfunction in asthma pathogenesis, both from anatomic and functional point of view. Furthermore an increasing amount of evidence demonstrates the relevance of innate immunity in polarizing a Th2 impaired response in asthmatic patients. Under this perspective, the complex cross-talking between airway epithelium, innate and adaptive immunity is emerging as a major determinant of type 2-inflammation beyond allergens. This review will include an update on the relevance of dysregulation of innate and adaptive type 2-immunity in asthma pathogenesis, particularly severe asthma, and on the role of the allergens that are associated with severe asthma. Type 2-immunity also will be reviewed in the light of the current and upcoming targeted treatments for severe asthma.

Pawankar R, et al. Asia Pac Allergy. 2020 Jan;10(1):e11. https://doi.org/10.5415/apallergy.2020.10.e11

The approaches to the diagnosis and treatment of chronic spontaneous urticaria (CSU) differ in various parts of the world. We sought to determine the adherence to international and national urticaria guidelines as well as the motives to deviate from the guidelines among physicians worldwide. A web-based questionnaire was created and launched via e-mail by the World Allergy Organization (WAO) to representatives of all WAO Member Societies, the members of the American Academy of Allergy, Asthma & Immunology (AAAAI) and the members of the WAO Junior Members Group (JMG), regardless of the specialty, affiliation, or nationality in March 2017. We received 1140 completed surveys from participating physicians from 99 countries. Virtually all participants (96%) were aware of at least one urticaria guideline and reported that they follow a guideline. However, one in five physicians who follow a guideline (22%) reported to deviate from it. Reliance on own clinical experience is the most frequent reason for deviation from guidelines or not following them (44%). Young (< 40 years) and less experienced physicians more often follow a guideline and less often deviate than older and experienced ones. Physicians who follow a urticaria guideline showed higher rates of routinely ordering a complete blood count, the erythrocyte sedimentation rate, C-reactive protein, anti-thyroid antibodies, and thyroid-stimulating hormone and of performing the autologous serum skin test as compared to those who do not. Physicians who follow a urticaria guideline showed higher rates of using second generation antihistamines as their first-line treatment of CSU (p = 0.001) and more frequently observed higher efficacy of these drugs (or had more confidence that it would work, p < 0.019) as compared to those who do not follow the guidelines. Physicians' characteristics (e.g. age, clinical experience, and specialty) and country specifics and regional features (e.g. availability of drugs for CSU treatment) importantly influence adherence to urticaria guidelines and CSU patient care and should be addressed in more detail in future research.

Background: Climatic and geographical characteristics may alter the plant distribution and thereby the patterns of allergens.Objective: To evaluate the profile of allergen sensitization in patients in southern Vietnam and its association with allergic diseases.Methods: We collected data of 423 patients who visited the Unit of Allergy and Clinical Immunology, University Medical Center, Vietnam from 2014 to 2021, from their medical records. Patients underwent skin prick tests to the 12 most common aeroallergens. Clinical evaluation and diagnosis of allergic diseases was done in consert with their allergen sensitization status.Results: Mites and cockroach were the most prevalent sensitizing allergens, with the sensitization prevalences as followed: Dermatophagoides farinae (Df) (59.8%), Dermatophagoides pteronyssinus (Dp) (50.4%), Blomica tropicalis (Bt) (49.6%), storage mites mix (10.4%), and cockroach (10.2%). Sensitization to Df was more predominant in males than in females (66% vs 54.1%). Dp-sensitized patients were younger than non-sensitized patients (29.01 ± 13.60 vs. 32.17 ± 14.89) whereas storage mites-sensitized patients were older than the non-sensitized groups (36.25 ± 13.53 vs. 28.76 ± 13.39) (p < 0.05 for all). A considerable proportion of patients with urticaria, allergic rhinitis, and atopic dermatitis were sensitized to mites. Polysensitization to different species of house dust mites (Dp, Df) and storage mites (Bt) was prevalent among patients sensitized to any kind of mites.Conclusions: Among people living in southern Vietnam, HDM mites, and cockroach were the predominant allergens. Further studies on the factors regulating the association between allergen sensitization with allergic diseases and polysensitization are crucial.

Purpose of review: To highlight the characteristics of allergic rhinitis, local allergic rhinitis (LAR), and importance of allergens in Southeast Asian countries. Recent findings: The Asia-Pacific region is very diverse with disparities in the epidemiological data between countries as well as in the unmet needs. The prevalence of allergic rhinitis has markedly increased in the past decades, with a high variation between countries, ranging from 4.5--80.3%. In terms of LAR, the reported prevalence in Southeast Asia is similar to that of other Asian countries (3.7–24.9%) but lower than that in western countries. House dust mites, cockroach, pollens, and molds are major allergens that are known triggers for of allergic rhinitis in this region, whereas the association with helminth infection requires further investigation. Summary: There are gaps and high variation between countries in Southeast Asia regarding the prevalence of allergic rhinitis and LAR. Further studies are needed to fully elucidate the association between allergens and allergic rhinitis in Southeast Asia.