The skin has a multifactorial aging process, caused by both intrinsic and extrinsic factors. A major theory of aging involves cellular senescence or apoptosis resulting from oxidative damage as the skin’s antioxidant system tends to weaken with age. The human microbiota is a complex ecosystem that is made up of microorganisms (bacteria, fungi, and viruses). Both gut and skin microbiota have essential roles in the protection against invading pathogens, mediating inflammatory conditions, and the modulation of the immune system which is involved in both innate and adaptive immune responses. However, the human microbiome could be changed during the life stage and affected by various perturbations. An alteration of the intestinal bacteria results in “microbial dysbiosis” which is associated with the influence of various diseases, including aging. The skin interactome is a novel integration of the “genome-microbiome-exposome” that plays a significant role in skin aging and skin health. Mitigating the negative impacts of factors influencing the skin interactome should be the future strategy to protect, prevent, and delay skin aging along with preserving healthy skin conditions. This review summarizes the current evidence on how human microbiomes affect skin aging and demonstrates the possible interventions, relating to human microbiomes, to modulate skin health and aging. Probiotics-based products are currently available mainly for the add-on treatment of many dermatologic conditions. However, at this point, there are limited clinical studies on skin anti-aging purposes and more are required as this evolving concept is on the rise and might provide an insight into future therapeutic options.

Chlorhexidine is a synthetic bisbiguanide antiseptic and was introduced in healthcare use in 1954. Allergy to chlorhexidine has been increasingly reported particularly in the perioperative and medical procedural settings. The hypersensitivity reactions range from mild cutaneous reactions to anaphylaxis or death. There are many products and medical devices containing chlorhexidine that sometimes lack standardized labeling. With the various routes of chlorhexidine exposure, accidental or recurrent reactions in chlorhexidine-allergic patients have been reported. Therefore, we aim to review the most recent evidence in clinical manifestations, diagnostic methods, management, and preventive measures with a focus on the unique features of chlorhexidine allergy.

Air pollution contributes to an estimated six million deaths per year. Epidemiological and experimental studies show an association between air pollutant exposure and respiratory allergy. We aimed to write a narrative review of the epidemiology of air pollution-related respiratory-related allergic disorders (including asthma and allergic rhinitis) and the effects of air pollutants - with an emphasis on the particulate matter - on respiratory allergy-related health. PubMed Medline was searched, and representative epidemiologic and controlled-exposure studies were selected by using terms for air pollutants, particulate matter, and respiratory allergy including asthma and allergic rhinitis. Epidemiological studies showed methodologic heterogeneity, including variability in study populations, geographical regions, types and sources of pollutants, methods for exposure estimation, approaches to controlling for confounding, and case definitions. This heterogeneity affected measures of association between studies. There is strong evidence to support an association between exposure to particulate matter and asthmatic exacerbations. Although data are inconclusive, several studies suggest exposure to particulate matter contributes to the development of asthma, allergic sensitization, and allergic rhinitis. Experimental studies, such as controlled-exposure studies, support a causal association between particulate matter and adverse health effects. Particulate matter exposure can exacerbate pre-existing asthma and may contribute to developing asthma, allergic rhinitis, and aeroallergen sensitization. Short-term and long-term strategies are needed to reduce disease severity and prevent new-onset disease development. Additional research is needed to identify effective avoidance strategies and therapeutic approaches.

Fruit allergies manifest with a diverse array of clinical presentations, ranging from localized contact allergies and oral allergy syndrome to the potential for severe systemic reactions including anaphylaxis. The scope of population-level prevalence studies remains limited, largely derived from single-center or hospital-based investigations. In this comprehensive review, we conducted a systematic literature search spanning the years 2009 to 2023, with full acknowledgment of potential analytical biases, to provide a global overview of fruit allergy prevalence. The primary mechanistic underpinning of fruit allergies stems from cross-reactivity between aeroallergens and food allergens, a consequence of structurally similar epitopes—a phenomenon recognized as pollen food allergy syndrome (PFAS). In the era of molecular allergology, numerous studies have dissected allergen components with substantial clinical relevance. Within this review, we explore important allergenic molecules found in plant-based foods, scrutinize pertinent cross-reactivity patterns, and offer insights into management recommendations. Additionally, we compare guideline recommendations to enhance clinical understanding and inform decision making.

Food-dependent exercise-induced allergic reactions (FDEIA) represent a distinct clinical phenomenon where symptoms arise during exercise following the consumption of specific trigger foods, with the most severe manifestation being anaphylaxis—a condition distinct from typical exercise-induced or food-induced anaphylaxis. In FDEIA, patients can either exercise or tolerate specific foods separately without experiencing any allergic reactions. Diagnosis relies on patient history and provocation testing, requiring rigorous implementation within a supervised hospital environment. Positive symptoms and clinical signs during testing confirm FDEIA, while negative outcomes do not preclude its presence. Exercise stands as the primary trigger, followed by nonsteroidal anti-inflammatory drugs (NSAIDs) and alcohol. The utilization of various protocols for food cofactor challenges to confirm FDEIA yields differing diagnostic outcomes. We highlight the updated concept of food cofactor challenges, incorporating protocols reported in the literature, and summarize current recommendations and comprehensive management approaches for FDEIA patients.

Anaphylaxis to CoronaVac, an inactivated vaccine against COVID-19, is extremely rare. We report 12 cases of anaphylaxis after CoronaVac administration, focusing on clinical characteristics and management outcomes. Skin test and graded vaccine challenge were successfully performed in our cases and might be considered if an inactivated vaccine is the only remaining option.