Oral and sublingual immunotherapy versus no therapy for egg allergy

Population: children with egg allergy

Setting: hospitals
Intervention: oral and sublingual immunotherapy for egg allergy. (Each study used a different oral immunotherapy protocol)

Comparison: placebo or egg‐free diet. (Three studies used placebo and seven studies used an egg avoidance diet as controls)

Increase in the amount of egg that could be tolerated

RR 7.48
(4.91 to 11.38)

410
(9 studies)

⊕⊕⊝⊝
low^1,2

82% of children in the oral immunotherapy group could ingest a partial serving of egg (1 g to 7.5 g) compared to 10% of the control group.

Complete recovery

RR 4.25
(2.77 to 6.53)

439
(10 studies)

⊕⊕⊝⊝
low^1,2

45% of children receiving oral immunotherapy were able to tolerate a full serving of egg compared to 10% of the control group.

Numbers of children with serious adverse events

Not estimable

439
(10 studies)

⊕⊕⊝⊝
low^1,2

All 10 trials reported numbers of children with serious adverse events (SAEs): SAEs requiring epinephrine/adrenaline occurred in 21/249 (8.4%) of children in the oral immunotherapy group and none in the control group.

Because adverse events were classified differently among the studies, it is difficult to comment on whether they were under‐ or over‐estimated. Surprisingly, only one study showed a high level of SAEs (Vazquez‐Ortiz 2014): 13 children required epinephrine/adrenaline administration 18 times, and one grade 5 reaction occurred.

Number of children with mild‐to‐severe adverse events

RR 8.35
(5.31 to 13.12)

439
(10 studies)

⊕⊕⊝⊝
low^1,2

Mild‐to‐severe adverse events were frequent; 75% of children presented mild‐to‐severe adverse events during oral immunotherapy treatment versus 6.8% of children in the control group.

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.