Pediatric allergen immunotherapy in the United States: Current practice, safety, and unmet needs for long-term and preventive outcomes.

Background: Allergen immunotherapy (AIT) is the only disease-modifying treatment for allergic rhinitis (AR), allergic asthma, and, potentially, atopic dermatitis (AD) in children. Despite demonstrated efficacy, AIT remains underutilized in the United States. Subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) both reduce symptoms and medication use, although much supporting evidence comes from non-U.S. studies by using extracts not approved domestically. Moreover, most U.S. trials of multiallergen SCIT lack rigorous placebo controlled data. Objective: The objectives were to examine current evidence on pediatric AIT, evaluate clinical efficacy and safety, and highlight key research gaps, particularly within the U.S. context. Methods: A literature search was conducted by using terms that included pediatric AIT, SCIT, SLIT tablets; SLIT drops; and off-label SLIT. The review focused on AIT for AR, asthma, and AD in children, with comparative analysis of SCIT and SLIT in terms of efficacy, safety, and preventative potential. Results: Both SCIT and SLIT are effective for AR and, to a lesser extent, asthma and AD. SLIT tablets offer the advantages of at-home use and a favorable safety profile but in the U.S. are limited to single allergens, which poses challenges for patients who were polysensitized. AIT shows potential for tertiary prevention, such as delaying asthma onset or reducing new sensitizations, although more U.S.-based pediatric data are needed. SCIT carries a risk of systemic reactions; SLIT maintains excellent safety. Knowledge gaps remain with regard to optimal treatment duration, extract formulation, and multiallergen use in children who are polyallergic. Conclusion: AIT is a valuable disease-modifying option for pediatric allergic diseases, but broader U.S. adoption is hindered by regulatory, reimbursement, and evidence limitations. Shared decision-making is critical to align treatment with patient needs. High-quality U.S.-based studies are essential to optimize care and long-term outcomes for children who are allergic.