Associations between Environmental dust composition and Atopic Dermatitis in urban and rural settings

Immunogenetics and pharmacogenetics of allergic asthma in Africa

Asthma is a common chronic condition in children and in an African setting is often highly prevalent in urban areas as compared to rural areas. Asthma is a heritable disease and the genetic risk is often exacerbated by unique localised environmental factors. The Global Initiative for Asthma (GINA) recommendation for the control of asthma includes inhaled corticosteroids (ICS) alone or together with short-acting β₂-agonists (SABA) or long-acting β₂-agonists (LABA). While these drugs can relieve asthma symptoms, there is evidence of reduced efficacy in people of African ancestry. Whether this is due to immunogenetics, genomic variability in drug metabolising genes (pharmacogenetics) or genetics of asthma-related traits is not well defined. Pharmacogenetic evidence of first-line asthma drugs in people of African ancestry is lacking and is further compounded by the lack of representative genetic association studies in the continent. In this review, we will discuss the paucity of data related to the pharmacogenetics of asthma drugs in people of African ancestry, mainly drawing from African American data. We will further discuss how this gap can be bridged to improve asthma health outcomes in Africa.

Skin morbidity in Indigenous children in relation to housing conditions in remote communities in Northwestern Ontario, Canada

BACKGROUND

Elevated rates of eczema and skin infections in Canadian First Nation (FN) communities are of concern to families, community leaders and healthcare professionals.

AIM

To determine whether skin morbidity was associated with indoor environmental quality factors in Canadian FN children living in remote communities.

METHODS

We quantified indoor environmental quality (IEQ) in the homes of FN children aged < 4 years of age living in four remote communities in the Sioux Lookout region of Northwestern Ontario, Canada. We conducted a quantitative housing inspection, including measuring surface area of mould (SAM), and monitored air quality for 5 days in each home, including carbon dioxide and relative humidity and quantified endotoxin in settled floor dust. We reviewed the medical charts of participating children for skin conditions and administered a health questionnaire. Relationships between IEQ and skin infections or eczema were evaluated using multivariable regression.

RESULTS

In total, 98 children were included in the descriptive analyses, of whom 86 had complete data and were evaluated in multivariate analyses for dermatological outcomes (mean age 1.6 years). Of these 86 children, 55% had made ≥ 1 visits to the local health centre (HC) for skin and soft tissue infections and 25.5% for eczema. Unexpectedly, annualized eczema visits were inversely associated with SAM (RR = 0.14; 95% CI 0.01-0.93). There was a trend suggesting an inverse relationship between endotoxin and HC encounters for eczema and skin and soft tissue infections.

CONCLUSION

Skin infections were common in this population of FN children. IEQ did not appear to be associated with skin infections or eczema. Mould exposure appeared to be inversely associated with HC encounters for eczema, possibly related to complex microorganism-host interactions occurring early in life.

Environmental Exposures may Hold the Key; Impact of Air Pollution, Greenness, and Rural/Farm Lifestyle on Allergic Outcomes

PURPOSE OF REVIEW

There has been an increased prevalence of allergy. Due to this relatively rapid rise, changes in environmental exposures are likely the main contributor. In this review, we highlight literature from the last 3 years pertaining to the role of air pollution, greenness, and the rural/farm lifestyle and their association with the development of allergic sensitization, atopic dermatitis, food allergy, and allergic rhinitis in infancy and childhood. Because asthma has a more complex pathophysiology, it was excluded from this review.

RECENT FINDINGS

Recent studies support a role for air pollution, greenness, and rural/farming lifestyle influencing atopic outcomes that continue to be defined. While many studies have examined singular environmental exposures, the interconnectedness of these exposures and others points to a need for future work to consider an individual's whole exposure. Environmental exposures' influence on atopic disease development remains an ongoing and important area of study.

Healthcare Disparities in Atopic Dermatitis in Latin America: A Narrative Review

INTRODUCTION

Atopic dermatitis (AD) is a chronic, pruritic skin disease caused by a mixture of genetic, immunological, and environmental factors, characterized by periods of inflammation and remission. In Latin America (LA), the prevalence of AD ranges up to 25% in children and 1-3% in adults. The natural history of the disease for most patients is that AD goes into remission in adolescence and adult life. Only 10-30% of patients continue to have symptoms of the disease in adulthood. There are patients (3-4%) who have the onset of AD during adolescence or after adulthood. Those with limited access to healthcare services, such as diagnosis and treatment, have increased difficulties coping with AD. Healthcare disparities are a complex topic that include social, political, racial/ethnic, and geographical factors. Publications about healthcare disparities in AD in LA are scarce. As a result, recognizing and resolving healthcare inequalities is critical to improving the treatment and quality of life (QoL) of individuals with AD.

METHODS

A panel of Latin American experts in dermatology and allergies was provided with a series of relevant questions to address before a multiday conference. During this conference, the entire group discussed and edited each narrative through numerous drafts and rounds of discussion until they reached a consensus.

RESULTS

This paper examines the barriers to equal access to care and recommends realistic actions to overcome them. Inadequate disease knowledge, cultural and linguistic barriers, stigmatization, maldistribution of resources, absence of local clinical practice guidelines, arduous patient journey, and limited consultation time were identified as causes of health inequality.

CONCLUSIONS

Among the suggested solutions are enhanced education for healthcare professionals, patients, and the general public, a focus on underprivileged communities, telemedicine and telementoring, translators, multidisciplinary teams, and local living clinical practice guidelines.

Endotoxin concentration and persistent eczema in early childhood

Although endotoxin concentration in the environment is negatively associated with atopic dermatitis (AD) onset in early childhood, the association between endotoxin concentration in the environment and eczema resolution in children with preexisting eczema is unclear. The aim of this study was to evaluate the association between endotoxin concentration in house dust and eczema persistence in young children. The authors used data from children participating in JECS (Japan Environment and Children's Study). In children who had AD or AD-like lesions at the age of 1 year, the authors investigated the association between the prevalence of eczema at the age of 3 years and endotoxin concentration (categorized by quartiles) in the dust on children's mattresses at the ages of 1.5 and 3 years. This study included 605 children. Eczema was significantly less prevalent among children whose mattresses were in the second and third quartiles of endotoxin concentration when they were 18 months old than among children whose mattresses were in the first quartile (adjusted odds ratio, 0.57 [95% confidence interval, 0.35-0.93] and adjusted odds ratio, 0.49 [95% confidence interval, 0.29-0.83], respectively). Moreover, of the children with eczema at age 3 years, those whose mattresses had endotoxin concentrations in the first quartile had significantly worse sleep disturbance caused by itchy rash (>1 time per week) than did those whose mattresses were in the third and fourth quartiles (20.0% vs 3.3% and 3.7%, both p values < 0.01). The findings indicate that low endotoxin exposure is associated with a higher prevalence of persistent eczema during early childhood.

(-)-α-Bisabolol Alleviates Atopic Dermatitis by Inhibiting MAPK and NF-κB Signaling in Mast Cell

(-)-α-Bisabolol (BIS) is a sesquiterpene alcohol derived mostly from Matricaria recutita L., which is a traditional herb and exhibits multiple biologic activities. BIS has been reported for treatment of skin disorders, but the effect of BIS on anti-atopic dermatitis (AD) remains unclear. Therefore, we investigated the effects of BIS on 2,4-dinitrochlorobenzene (DNCB)-induced AD in BALB/c mice and the underlying mechanism in Bone Marrow-Derived Mast Cells (BMMCs). Topical BIS treatment reduced AD-like symptoms and the release of interleukin (IL)-4 without immunoglobulin (Ig)-E production in DNCB-induced BALB/c mice. Histopathological examination revealed that BIS reduced epidermal thickness and inhibited mast cells in the AD-like lesions skin. Oral administration of BIS effectively and dose-dependently suppressed mast-cell-mediated passive cutaneous anaphylaxis. In IgE-mediated BMMCs, the levels of β-hexosaminidase (β-hex), histamine, and tumor necrosis factor (TNF)-α were reduced by blocking the activation of nuclear factor-қB (NF-қB) and c-Jun N-terminal kinase (JNK) without P38 mitogen activated protein (P38) and extracellular regulated protein kinases (Erk1/2). Taken together, our experimental results indicated BIS suppresses AD by inhibiting the activation of JNK and NF-κB in mast cells. BIS may be a promising therapeutic agent for atopic dermatitis and other mast-cell-related diseases.