Current options in the management of tree nut allergy. A systematic
review and narrative synthesis.
Abstract
Background: Tree nut allergy is usually life-long and
potentially life-threatening. Standard of care consists of strict
avoidance of the culprit nut and symptomatic treatment of accidental
reactions. Objective: To evaluate the potential therapeutic
options for desensitization of patients with IgE-mediated tree nut
allergy, focusing on, but not limited to, immunotherapy.
Methods: We systematically searched three bibliographic
databases for studies published until July 2022 for active treatments of
IgE-mediated allergy to tree nuts (walnut, hazelnut, pistachio, cashew,
and almond) with allergen-specific immunotherapy (AIT) using oral (OIT),
sublingual (SLIT), epicutaneous (EPIT) or subcutaneous (SCIT) delivery,
or with other disease-modifying treatments. Results: We
included 17 studies (three randomized, double-blinded,
placebo-controlled, five quasi-experimental prospective cohorts, five
prospective cohorts, two retrospective cohorts, and two case reports.
Three studies investigated sublingual immunotherapy, five investigated
oral immunotherapy to a single tree nut, and six used multi-food oral
immunotherapy with (four) or without (two) omalizumab. The remaining
studies investigated the effectiveness of monoclonal antibodies in
multi-food allergic patients, including patients with a tree nut
allergy. The heterogeneity of the studies prevented pooling and
meta-analysis. Conclusion: Even though strict avoidance remains
the standard of care for patients with tree nut allergy, alternative
approaches have been tested in clinical trials and real-life studies.
These new concepts require further investigation with more well-designed
studies including well-characterized nut allergic patients before
implementing them in daily clinical practice.