Leonard Bielory

Purpose of review: To explore our current understanding of receptor profiles acted upon by medications used to treat dry eye disease (DED). Recent findings: Research into histaminic and muscarinic receptor affinities for drugs targeting the ocular surface has not kept up with bench research pertaining to the receptor profile of the ocular surface. These insights are necessary for better evaluation of medications used in DED and other allergic disorders. Summary: At the H1 receptor, Ketotifen (pK_a = 9.2), pyrilamine (pK_a = 9.0), and epinastine (pK_a = 8.0) had the highest affinities, whereas ranitidine (pK_a = 4.2) and cimetidine (pK_a = 4.9) had the lowest. Ketotifen, a second-generation antihistamine, was found to have a pK_a of 6.7 at muscarinic receptors which was higher than that of diphenhydramine (pK_a = 6.4), a first-generation antihistamine. Additionally, second-generation antihistamines have higher affinity for H3 receptors, which have been linked to urticaria, compared to first-generation. Azelastine, a second-generation, demonstrated significant affinity (pK_a = 7.1) at the H3 receptor compared to all other drugs. Antazoline (pK_a = 4.4) and diphenhydramine (pK_a = 4.6), both first-generation antihistamines, had the lowest affinities for the H3 receptor. These findings raise questions about the use of antihistamines in the treatment of DED and allergic disorders.

Purpose of review: The purpose of this review is to highlight and compare the structural and functional differences between the ocular surface and the skin. The goal is to further understand how these components interact from an immunobiological standpoint, which may inform future therapeutic uses. Recent findings: Treatment agents, such as Dupilumab and Apremilast are traditionally indicated for integumentary conditions, such as atopic dermatitis and psoriasis, respectively. Both were also found to have potent effects on the conjunctival surface and ocular glands, which may be attributed to the similarities in structure. Summary: Surfaces of the eyes and the skin are found to have similar composition in terms of immunohistology, steroidogenic properties, and allergic mechanisms. These translate directly into both the adverse effects and therapeutic benefits that overlap when treating these surfaces.

Purpose of review: Allergic rhinoconjunctivitis is one of the most common ocular surface allergic inflammatory conditions seen in primary care that impacts patient's quality of life. Allergic conjunctivitis is increasingly being recognized as its own symptom complex that negatively impacts patient's quality of life separate from allergic rhinitis. This article reviews the psychosocial impact of ocular surface allergic inflammatory disorders (namely seasonal allergic conjunctivitis, ocular allergy, perennial allergic conjunctivitis, and atopic keratoconjunctivitis) on adult and pediatric populations. Recent findings: Despite the perception that allergic conjunctivitis is a trivial condition, it imposes a burden on numerous psychosocial aspects of life for adolescents and adults. Several questionnaires specific to rhinoconjunctivitis have been found to be effective tools at gauging quality of life (QoL) and communicating impairments in specific behavioral domains for adult and pediatric populations. An emerging focus on the role of hormone fluctuations and age on ocular surface allergic inflammation underscores the importance of nuancing the physiologic effects on ocular allergy and QoL at every decade of life. Summary: Further exploration and research of symptoms by age would greatly improve our understanding of age's impact on QoL in these patients and contribute to improved management of allergic conjunctivitis.

Background: Many allergists consider the ocean breeze to be free of allergens and recommend visits to the coast for relief; however, the coast may perpetuate an allergenic environment. Objective: This study investigated the sea breeze's impact on spore dispersion between coastal and inland sites, and the potential implications of sea breeze on human health and coastal resources. Methods: Spore sampling occurred during 2006 by using pollen samplers. Samplers were located at the Rutgers University Institute of Marine and Coastal Sciences Marine Field Station and the Rutgers University Pinelands Field Station. Statistical analysis was performed on the spore data to compare concentrations from the various locations. The effect of sea breeze circulation on particulate matter was analyzed from meteorological data collected in 2006. Sea breeze data were collected from simulations, Doppler radar, and meteorological towers at varying heights. Results: There was no significant difference between the total spore concentration at the New Jersey coast and the New Jersey Pinelands canopy. Conclusion: Sea breeze has been shown to favor aerobiologic transfers from coastal seawater to land, but the immediate environment (floor) still remains a primary determinant of affecting an individual's allergic airway disease. Results of some studies have shown that coastal environments may favor the onset allergic airway, but in our study this seemed to be equivalent to the floor (or immediate locale) of an individual affected with allergy. However, the sea breeze effect seemed to have the ability to impact allergic airway disease (AAD) populations not only living along the coasts but of those living up to 130 km inland and potentially those living in the Philadelphia metropolitan area.

Pollen exposure weakens the immunity against certain seasonal respiratory viruses by diminishing the antiviral interferon response. Here we investigate whether the same applies to the pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is sensitive to antiviral interferons, if infection waves coincide with high airborne pollen concentrations. Our original hypothesis was that more airborne pollen would lead to increases in infection rates. To examine this, we performed a cross-sectional and longitudinal data analysis on SARS-CoV-2 infection, airborne pollen, and meteorological factors. Our dataset is the most comprehensive, largest possible worldwide from 130 stations, across 31 countries and five continents. To explicitly investigate the effects of social contact, we additionally considered population density of each study area, as well as lockdown effects, in all possible combinations: without any lockdown, with mixed lockdown−no lockdown regime, and under complete lockdown. We found that airborne pollen, sometimes in synergy with humidity and temperature, explained, on average, 44% of the infection rate variability. Infection rates increased after higher pollen concentrations most frequently during the four previous days. Without lockdown, an increase of pollen abundance by 100 pollen/m³ resulted in a 4% average increase of infection rates. Lockdown halved infection rates under similar pollen concentrations. As there can be no preventive measures against airborne pollen exposure, we suggest wide dissemination of pollen−virus coexposure dire effect information to encourage high-risk individuals to wear particle filter masks during high springtime pollen concentrations. Significance Coexposure to airborne pollen enhances susceptibility to respiratory viral infections, regardless of the allergy status. We hypothesized this could be also true for SARS-CoV-2 infections. To investigate this, we tested for relationships between SARS-CoV-2 infection rates and pollen concentrations, along with humidity, temperature, population density, and lockdown effects. Our unique dataset derives from 130 sites in 31 countries and across five continents. We found that pollen, sometimes in synergy with humidity and temperature, explained, on average, 44% of the infection rate variability. Lockdown halved infection rates under similar pollen concentrations. As we cannot completely avoid pollen exposure, we suggest wide dissemination of pollen−virus coexposure information to encourage high-risk individuals to wear particle filter masks during high springtime pollen concentrations.

Significance: Human-caused climate change could impact respiratory health, including asthma and allergies, through temperature-driven increases in airborne pollen, but the long-term continental pollen trends and role of climate change in pollen patterns are not well-understood. We measure pollen trends across North America from 1990 to 2018 and find increases in pollen concentrations and longer pollen seasons. We use an ensemble of climate models to test the role of climate change and find that it is the dominant driver of changes in pollen season length and a significant contributor to increasing pollen concentrations. Our results indicate that human-caused climate change has already worsened North American pollen seasons, and climate-driven pollen trends are likely to further exacerbate respiratory health impacts in coming decades.