Dilute apple cider vinegar soaks did not improve skin barrier integrity in patients with atopic dermatitis (AD), according to study data published in Pediatric Dermatology. However, apple cider vinegar soaks were associated with mild skin irritation.
Patients with AD and healthy controls, 12 years of age or older, were recruited from the University of Virginia. Participants soaked a forearm in dilute apple cider vinegar (0.5% acetic acid) and the other forearm in tap water for 10 minutes daily for 14 days. The apple cider vinegar soak concentration was determined based on prior research demonstrating its safety and tolerability. Transepidermal water loss (TEWL) and skin pH were recorded from volar forearms at baseline; at 0, 15, 30, and 60 minutes after the first soak; and 24 hours after completion of the 14-day treatment course. Skin discomfort levels were patient graded and reported.
Eleven patients with AD (geometric mean [GM] age, 20.6 years) and 11 healthy controls (GM age, 28.8 years) were enrolled in the study. Patients with AD had a GM SCORing Atopic Dermatitis score of 32.9 (95% CI, 23.8-45.4). At baseline, TEWL was significantly elevated in patients (GM, 11.1; 95% CI, 8.6-14.3 g/m2/h) compared with healthy controls (GM, 7.1; 95% CI, 6.0-8.4 g/m2/h). Pretreatment skin pH was comparable between patients (GM, 4.88; 95% CI, 4.67-5.10) and controls (GM, 4.86; 95% CI, 4.60-5.13). In both study groups, TEWL was increased immediately following apple cider vinegar soak compared with baseline. However, among patients, TEWL returned to baseline after 30 minutes. Compared with baseline levels, skin pH was decreased at 0 minutes following apple cider vinegar soak in all participants. Skin pH remained decreased 15 minutes post-soak in patients and 60 minutes post-soak in controls. Among patients with AD, the effect of 14 days of apple cider vinegar soaks on TEWL and pH was comparable with soaking in water alone (P =.65 and P =.47, respectively). Additionally, the majority (72.7%) of participants reported mild discomfort from apple cider vinegar soaks, which improved with discontinuation.
Limitations of the study include the young age and small number of homogenous participants as well as the testing on only the volar forearms. Additional limitations include analysis of only one brand of apple cider vinegar product, dilution, and application of the apple cider vinegar soak.
Although apple cider vinegar soaks resulted in TEWL increase and skin pH decrease among patients with AD, the researchers noted that results were transient and did not persist following 14 days of treatment. As such, apple cider vinegar treatment had no effect on “skin barrier integrity in AD in a significant manner.” Further study of apple cider vinegar in lower concentrations is necessary to explore its potential therapeutic effects for patients with AD.
Luu LA, Flowers RH, Kellams AL, et al. Apple cider vinegar soaks [0.5%] as a treatment for atopic dermatitis do not improve skin barrier integrity [published online July 22, 2019]. Pediatr Dermatol. doi:10.1111/pde.13888