Allergic diseases in India - Prevalence, risk factors and current challenges

Impact of socioeconomic factors on pediatric atopic dermatitis population

BACKGROUND

Atopic dermatitis (AD), or eczema, is a chronic, pruritic inflammatory skin disease affecting children and adults. Socioeconomic status (SES) plays a significant role in developing AD. However, mixed evidence from a previous study by Bajwa et al makes it difficult to determine the directionality of the association. There is a literature gap in understanding the causal association between AD and socioeconomic factors.

AIM

To evaluate the impact of disparities in SES on pediatric AD populations.

METHODS

Based on the eligibility criteria, the literature review identified eight articles since July 2021, and a descriptive analysis was conducted using an Excel spreadsheet on key components collected from the identified studies.

RESULTS

Eight observational studies assessed SES in pediatric AD. Five observational studies showed mixed associations between AD and SES. Sub-analysis revealed that urban areas had a higher prevalence of AD, and four studies identified a positive association between parental education and AD in the pediatric population. Socioeconomic variables, such as residential areas and household income, significantly influence disease outcomes.

CONCLUSION

There is mixed association between pediatric AD and SES, with AD positively associated with parental education. There is critical need to evaluate global impact of SES variables on pediatric AD.

Insomnia Associated With Increased Risk of Atopic Dermatitis: A Two-Sample Mendelian Randomization Study

BACKGROUND

The causal relationships between sleep traits and allergic diseases remain unclear. This study sought to explore their causal associations using Mendelian randomization (MR) analysis.

METHODS

This study utilized summary-level data from genome-wide association studies (GWAS) and selected genetic variants associated with sleep traits as instrumental variables (IVs). For the primary analysis, the inverse-variance weighted (IVW) method was utilized. To further evaluate causal effects, we applied weighted median, weighted mode, and MR-Egger regression. Sensitivity analyses, such as linkage disequilibrium score (LDSC) regression, MR-Egger regression, Cochran's Q test, leave-one-out analysis, and MR-PRESSO, were carried out to confirm result robustness.

RESULTS

IVW analysis revealed that genetically predicted insomnia was causally associated with a higher risk of atopic dermatitis (OR = 1.79, 95% CI: 1.17-2.74, P = 0.01), and preferring an evening chronotype was causally associated with a lower risk of allergic rhinitis (IVW: OR = 0.99, 95% CI: 0.99-1.00, P = 0.02). The LDSC analysis further identified a significant genetic correlation between insomnia and atopic dermatitis (rg = 0.107, P = 0.039), but not between chronotype and allergic rhinitis (rg = -0.036, P = 0.339). No significant connections were identified between other sleep traits and allergic diseases. The MR-Egger intercept test did not indicate pleiotropy, except for the association with allergic asthma.

CONCLUSION

Chronotype and insomnia were causally associated with the efficacy of sleep-based interventions in allergic disease management.

Penicillin Allergy Management in India and Sri Lanka: Current Challenges

Data regarding Penicillin allergy labels (PALs) from India and Sri Lanka are sparse. Emerging data suggests that the proportion of patients declaring an unverified PAL in secondary care in India and Sri Lanka (1%-4%) is lesser than that reported in High Income Countries (15%-20%). However, even this relatively small percentage translates into a large absolute number, as this part of the world accounts for approximately 25% of the global population. There is a huge unmet need for allergy specialists in India and Sri Lanka. Penicillin allergy management is further compromised by unavailability of skin test reagents, lack of formal training in drug allergy, pre-emptive, non-standardised and unregulated skin testing by untrained operators and a weak health service framework. This has an adverse impact on antimicrobial stewardship, particularly in the management of rheumatic fever, rheumatic heart disease, bacterial endocarditis, syphilis and other sexually transmitted infections. This narrative review highlights the burden of PALs in India and Sri Lanka, as well as gaps in the published literature. It describes current challenges and a pragmatic, cautious and staged bespoke mitigation approach to improve and standardise antimicrobial stewardship in accordance with the World Health Organisation AWaRe guidance.

Silibinin, a PLC-β3 inhibitor, inhibits mast cell activation and alleviates OVA-induced asthma

The immunoglobulin E (IgE) receptor FcεRI (Fc epsilon RI) plays a crucial role in allergic reactions. Recent studies have indicated that the interaction between FcεRIβ and the downstream protein phospholipase C beta 3 (PLCβ3) leads to the production of inflammatory cytokines. The aim of this study was to develop small molecules that inhibit the protein-protein interactions between FcεRIβ and PLCβ3 to treat allergic inflammation. Additionally, PLCβ3 has emerged as a potential target protein for treating allergic inflammation. In this study, we employed a virtual screening technique to search the Taiwan Traditional Chinese Medicine Database, followed by a second screening using absorption, distribution, metabolism, excretion, and toxicity (ADMET). Among the compounds screened, silibinin exhibited the best performance, forming strong hydrogen bond interactions with residues of PLCβ3, with a binding free energy of -119.277 kcal/mol. Therefore, silibinin effectively blocked the interaction between FcεRIβ and PLCβ3. Silibinin reduced the production of allergic inflammatory cytokines, including cytokine-induced neutrophil chemoattractant 2a (CINC-2a), interleukin-2 (IL-2), cytokine-induced neutrophil chemoattractant 1 (CINC-1), interleukin 1α (IL-1α), macrophage inflammatory protein 3 alpha (MIP3α), interferon γ (IFN-γ), activin A, granulocyte macrophage colony stimulating factor (GM-CSF), intercellular adhesion molecule-1 (ICAM-1), interleukin 4 (IL-4), interleukin 13 (IL-13), Fas ligand (FasL) and tumor necrosis factor alpha (TNF-α), without inducing cytotoxicity. Furthermore, in studies of IgE-mediated allergic responses, silibinin also decreased the expression of surface IgE receptors (FcεRIs). Moreover, silibinin effectively alleviated allergen-induced asthma responses and reduced the infiltration of inflammatory immune cells into the lungs of an OVA-induced allergic airway inflammation mouse model. Taken together, these results demonstrate the potential antiallergic mechanism of silibinin both in vitro and in vivo, making it a promising candidate for the development of asthma therapeutics.

Unveiling the Impact of Smoking on Allergic Rhinitis: Disease Severity and Efficacy of Subcutaneous Immunotherapy

OBJECTIVE

To evaluate the impact of smoking statuses on disease severity and subcutaneous immunotherapy (SCIT) efficacy in allergic rhinitis (AR).

STUDY DESIGN

Open observational cohort study.

SETTING

Tertiary referral center.

METHODS

Five hundred and five AR patients undergoing dust mite allergen SCIT were categorized into never smokers, former smokers, and current smokers. AR severity was assessed using widely employed questionnaires. The changes in questionnaire scores pre- and post-SCIT were evaluated for SCIT efficacy. The differences in disease severity and SCIT efficacy were compared for different smoking statuses among AR patients.

RESULTS

Compared to never smokers, former and current smokers exhibited higher proportion of male, alcohol, and asthma (P < .05). Current smokers had a greater prevalence of allergic conjunctivitis than former smokers (P < .05). Before SCIT, AR severity was similar across 3 groups, even after adjusting for confounders (P > .05). Current smokers reported lower SCIT efficacy in the first year (P < .05). By the third year, 3 groups showed comparable long-term efficacy (P > .05). However, current smokers experienced a significant decrease in benefits 2 years post-SCIT (P < .05) and lower improvement rates at the end of the 3-years SCIT period and 2 years following SCIT (P < .05).

CONCLUSION

AR patients across different smoking statuses demonstrated similar baseline disease severity and long-time SCIT efficacy. Active smoking was associated with increased asthma risk, delayed early SCIT efficacy perception, reduced improvement over 3 years, and diminished benefits 2 years after SCIT. Prompt smoking cessation is crucial to mitigate these effects.

Migraine, Allergy, and Histamine: Is There a Link?

The relationship between migraines and allergies is controversial. Though they are epidemiologically linked, the underlying pathophysiological connection between them remains unclear. Migraines and allergic disorders have various underlying genetic and biological causes. As per the literature, these conditions are epidemiologically linked, and some common pathophysiological pathways have been hypothesized. The histaminergic system may be the clue to understanding the correlation among these diseases. As a neurotransmitter in the central nervous system with a vasodilatory effect, histamine has a well-documented influence on the allergic response and could be involved in the pathophysiology of migraines. Histamine may influence hypothalamic activity, which may play a major role in migraines or may simply influence their severity. In both cases, antihistamine drugs could prove useful. This review examines whether the histaminergic system, particularly H3 and H4 receptors, may provide a mechanistic link between the pathophysiology of migraines and allergic disorders, two common and debilitating conditions. Identifying their connection could help identify novel therapeutic strategies.

Allergic sensitization to foods in India and other Low-Middle-income countries

Food allergy is an important cause of morbidity, significantly affecting the quality of life of the sufferer. Most food allergy research has been undertaken in high-income countries. Here, we summarize literature regarding food allergy in India and other low-middle-income countries (LMIC). We provide summaries of self-reported adverse food reactions and food sensitization in these regions by reviewing published community-based studies of prevalence, burden, and risk factors. We identified 2 community-based studies of food allergy prevalence in Karnataka, India, which estimate that food allergy affects just 0.14% of children and 1.2% of adults. The overall prevalence of allergic sensitization to 'any' food was 26.5% in adults and 19.1% in children by serum-specific IgE; but only 4.48% in children by skin prick test. We identified a further 28 studies in other LMICs, mainly from China but also Turkey, South Africa, Ghana, Mexico, Brazil, Thailand, Philippines, and Korea. The overall prevalence of allergic sensitization to 'any' food ranged from 0.11% to 16.8% in children using serum-specific IgE and 0.14% to 9.6% in children by skin prick test. The questionnaires and skin prick testing materials used and number of allergens tested varied significantly between studies. Other than Karnataka, there is no information on prevalence of food sensitization and probable food allergy in the community in India. Similar lack of information is noted among the majority of the 136 LMICs. Where community-based studies have been undertaken, there is wide variation in the prevalence and patterns of food sensitization across different LMICs, at least partly due to variations in study methodology. International collaboration is required in order to formally assess food allergy prevalence and burden across representative samples from multiple LMICs.

A review on aero-allergen induced allergy in India

Allergic diseases such as bronchial asthma, rhinitis and eczema are an important public health issue globally in 21st century. Their prevalence and impact in India is high, in terms of total numbers of people affected. Due to diverse climate and lifestyle, the Indian population is exposed to a rich and varied range of aerobiological particles. In the last two decades in India, 83 pollens, 34 fungi, six dust mite and 19 insect species were reported as allergenic, often contributing to heavy allergenic exposure in indoor and outdoor environments. There are currently few practitioners who offer allergy diagnosis and treatment in India, but there is active basic and molecular research aiming to improve the health of allergic patients. This review explores the field of aero-allergy in India during the last two decades, with special emphasis on prevalence across various centres and relevant scientific advances such as genetic associations and new therapeutics. This review will be helpful for clinicians to select aero-allergens for sensitisation testing in patients suffering from symptoms in different regions of India, and to support patients undertaking prophylaxis of allergic symptoms in India according to local environmental conditions. This study also helps to define patient selection for allergy testing and the role of test results in guiding allergic disease management in the Indian context. Finally, we summarize genetic findings relevant to aero-allergy in India and discuss the development of novel therapeutics for investigation and management of aero-allergy in India.