Jonathan Silverberg, MD, PhD, MPH
Still, some patients seek alternative or adjunctive treatment approaches, owing to a desire to identify the root cause of disease, their aversion toward Western medicine, or fear of adverse events. Yepes-Nuñez and colleagues performed a systematic review and meta-analysis including 23 studies of benefits and harms of allergen immunotherapy for AD. I had the privilege of participating in this study and can testify to the astronomical amount of work that went into comprehensively identifying all of the relevant studies and synthesizing the data. We found that adjunctive subcutaneous or sublingual allergen immunotherapy, particularly for house dust mites, led to modest but generally delayed improvements of AD severity, itch, and quality of life, and less definitive effects on sleep disturbance and AD flares. Overall, both were well tolerated, though subcutaneous immunotherapy was associated with more adverse events than sublingual immunotherapy. Allergen immunotherapy requires a significant investment of time by patients and was only modestly effective. Nevertheless, it may be a reasonable approach to consider in select patients with AD.
Benjamin Franklin famously stated that "an ounce of prevention is worth a pound of cure." Likewise, while successful treatment of AD is great, how can we advise patients and caregivers of children who are at high risk for AD? To answer this question, Voigt and Lele performed a systematic review and meta-analysis of 11 randomized controlled trials examining the efficacy of Lactobacillus rhamnosus at preventing AD in children when taken by mothers during pregnancy. They found that L. rhamnosus significantly reduced the risk of developing AD within 2 years, marginally significantly reduced risk at 4-5 years, and significantly reduced risk at 6-7 years, but no significant risk differences were observed at 10-11 years. The authors concluded that use of L. rhamnosus with or without other probiotics during pregnancy reduces the incidence of childhood AD at least up to age 7 years.
Wang and colleagues conducted an observational study of the relationship of home environment exposures with atopic disease, including AD, in 17,881 offspring from Iceland, Norway, Sweden, Denmark, and Estonia who had undergone two follow-up investigations every 10 years. They found that AD was associated with parent-reported visible mold and dampness/mold at home, living in an apartment, and living in newer buildings. Avoidance of these environmental exposures could possibly decrease the risk of developing AD, although future confirmatory studies are needed.
For each of these treatment/prevention approaches, the magnitude of benefit is not very large. Thus, these approaches do not replace our armamentarium of treatments and avoidance strategies for AD. Rather, they can be used complementarily as low-risk add-on interventions with a potential upside.