Is epicutaneous immunotherapy (patch-based therapy) safe and effective in reducing the severity of peanut allergy in children 1 to 3 years of age?
Epicutaneous therapy using a peanut patch reduced the severity of reactions and was more likely to increase the dose required to elicit a reaction. However, one-third of children responded without any intervention (natural history of the condition) and anaphylactic reactions were more common in the treated group. Most important, long-term follow-up of serious allergic reactions was not part of this study.
Plan de l'etude:
Randomized controlled trial (double-blinded)
Epicutaneous immunotherapy is used to treat peanut allergy in children 4 years and older, but these industry-sponsored authors hypothesize that earlier treatment may be more effective. They recruited 362 children aged 1 to 3 years with physician-diagnosed peanut allergy, an IgE level specific for peanuts greater than 0.7 kUA/L, a skin prick test generating a wheal at least 6 mm in diameter, and a reaction elicited by a dose of peanut protein of less than 300 mg. Children were randomized in a 2:1 ratio to epicutaneous immunotherapy using a commercial 250-mcg peanut patch (Viaskin Peanut) or matching placebo patch applied daily for 12 months. The patch was initially applied for 3 hours per day with the duration increased over time using a prespecified protocol. Groups were balanced at baseline with a median age of 2.5 months, 69% boys, and an allergic reaction–eliciting dose of 100 mg to 300 mg in approximately two-thirds (lower in the remainder). Analysis was by intention to treat. Approximately 15% children in each group dropped out before the end of the trial. The primary outcome was considered met if children with a baseline eliciting dose greater than 10 mg achieved a 12-month eliciting dose of at least 1000 mg of peanut protein, or if children with a lower baseline eliciting disease achieved a final eliciting dose of at least 300 mg. (Note that 300 mg is approximately one peanut, so the goal is not to eliminate peanut allergy, but rather to make accidental exposure less likely to trigger an allergic reaction.) The primary outcome was met significantly more often in the intervention group (67.0% vs 33.5%; P < .001; number needed to treat = 3). At 12 months, a food challenge elicited a mild or absent response more often in the peanut patch group (36.5% vs 19.4%). Moderate adverse events were more common in the peanut patch group, including site swelling (72.5% vs 39.0%) and pruritus (94.5% vs 61.0%). Anaphylaxis occurred more often in the intervention group (7.8% vs 3.4%; statistical significance not reported), and 8 patients in the intervention group were withdrawn from the trial due to adverse events compared with 0 in the placebo group. By the end of the trial, children were wearing the patch almost all day long.
Mark H. Ebell, MD, MS
University of Georgia