Apple cider vinegar soaks do not alter the skin bacterial microbiome in atopic dermatitis.

INTRODUCTION: Atopic dermatitis is a common skin disease characterized by altered cutaneous immunity in which patients often exhibit lower skin microbiota diversity compared to healthy skin and are prone to colonization by Staphylococcus aureus. Apple cider vinegar has been shown to have antibacterial effects; however, its effects on the skin microbiome have not previously been well-described. OBJECTIVES: We aimed to examine the effects of topical dilute apple cider vinegar soaks on Staphylococcus aureus abundance, skin bacterial microbiome composition, and skin bacterial microbiome diversity in atopic dermatitis participants compared to healthy skin. METHODS: Eleven subjects with atopic dermatitis and 11 healthy controls were enrolled in this randomized, non-blinded, single-institution, split-arm pilot study. Subjects soaked one forearm in dilute apple cider vinegar (0.5% acetic acid) and the other forearm in tap water for 10 minutes daily. Skin bacteria samples were collected from subjects' volar forearms before and after 14 days of treatment. 16S sequencing was used to analyze Staphylococcus aureus abundance and skin bacterial microbiome composition, and alpha diversity of microbiota were determined using Shannon diversity index. RESULTS: There was no difference in skin bacterial microbiome in atopic dermatitis subjects after 2 weeks of daily water or apple cider vinegar treatments (p = 0.056 and p = 0.22, respectively), or in mean abundance of S. aureus on apple cider vinegar-treated forearms (p = 0.60). At 2 weeks, the skin bacterial microbiomes of healthy control subjects were not significantly different from the skin bacterial microbiome of atopic dermatitis subjects (p = 0.14, 0.21, 0.12, and 0.05). CONCLUSIONS: Our results suggest that daily soaks in 0.5% apple cider vinegar are not an effective method of altering the skin bacterial microbiome in atopic dermatitis. Further studies are needed to explore the effects of different concentrations of apple cider vinegar on skin microflora and disease severity. TRIAL NUMBER: UVA IRB-HSR #19906.

Apple cider vinegar soaks [0.5%] as a treatment for atopic dermatitis do not improve skin barrier integrity.

BACKGROUND/OBJECTIVES: Atopic dermatitis (AD) is a common chronic inflammatory skin condition associated with high transepidermal water loss, high skin pH, and Staphylococcus aureus skin colonization. The treatment of AD with bath additives remains highly debated. Recent evidence suggests that dilute apple cider vinegar (ACV) may improve skin barrier integrity in AD, but its safety and efficacy are not well studied. This pilot split-arm study analyzed the effect of dilute apple cider vinegar soaks on skin barrier integrity in patients with atopic dermatitis as measured by skin transepidermal water loss and skin pH. METHODS: A total of 22 subjects (11 AD and 11 healthy controls) were enrolled. Subjects soaked both of their forearms for 14 days, with one arm in dilute ACV (0.5% acetic acid) and the other in water 10 minutes daily. Transepidermal water loss and pH were measured pre- and post-treatment. RESULTS: In both groups, transepidermal water loss increased and pH decreased at 0 minutes post-ACV treatment, but these effects were not sustained at 60 minutes. In total, 72.7% (16/22) of subjects reported mild side effects from ACV with improvement after discontinuing the soaks. CONCLUSIONS: Dilute ACV soaks have no significant effect on skin barrier integrity but caused skin irritation in a majority of subjects. Study limitations include analysis of a single brand, dilution, and application of ACV. Future studies are needed to explore whether lower concentrations of ACV soaks or other applications such as a leave-on acidic ointment could improve skin barrier integrity in a safe, nonirritating way.

Nasal IgE production in allergic rhinitis: Impact of rhinovirus infection.

BACKGROUND: Rhinovirus (RV) infections exacerbate asthma in part by enhancing an allergic state, and these exacerbations can be mitigated via administration of anti-IgE. OBJECTIVE: We investigated the presence of local IgE production in the nose of allergic and non-allergic subjects and assessed whether this was enhanced by RV. METHODS: Local production of specific IgE was determined by comparing ratios of specific to total IgE concentrations between nasal and serum samples. Our initial studies were performed in subjects presenting to the emergency department for allergic and non-allergic respiratory complaints. Subsequently, we investigated influences of experimental RV infection on nasal sIgE production in an allergic cohort. RESULTS: We found evidence of local sIgE production to Dermatophagoides pteronyssinus in 30.3% and to Blomia tropicalis in 14.6% of allergic subjects. None of the non-allergic subjects demonstrated local IgE. Subjects with active RV infection were more than twice as likely to have local sIgE (45% vs 14%), and subjects with local sIgE being produced were ~3 times more likely to be having an asthma exacerbation. Experimental RV infection was able to induce local sIgE production. CONCLUSION: These studies confirm local IgE production in a large subset of allergic subjects and demonstrate that allergic asthmatics with local IgE are more likely to develop an asthma exacerbation when infected with RV. Our RV challenge studies demonstrate that at least some allergic asthmatics can be induced to secrete locally generated IgE in their nasal airway after RV infection.