Transepidermal water loss predicts reaction severity in peanut oral food challenge
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Key takeaways:
- Anaphylaxis is a risk in oral food challenges.
- Differences in transepidermal water loss by sex and race were not significant.
- Greater baseline TEWL correlated with more severe reactions.
WASHINGTON — Baseline transepidermal water loss predicted the severity of reactions during oral food challenges for peanut allergy, according to a poster presented at the American Academy of Allergy, Asthma & Immunology Annual Meeting.
Greater baseline transepidermal water loss (TEWL) correlated with more severe reactions during OFCs overall as well, George E. Freigeh, MD, a senior allergy fellow in the division of allergy and clinical immunology in the department of internal medicine at the University of Michigan, and colleagues wrote.
“Oral food challenges remain the gold standard for diagnosing food allergies, despite concerns over inducing anaphylaxis,” Freigeh said during his presentation. “So, finding ways in which oral food challenges can become more accessible and more easily done is vital.”
The study involved 234 patients participating in OFCs at the University of Michigan’s food allergy clinics. Researchers measured participants’ TEWL on their volar forearm before they took part in the OFCs.
“Allergists unaware of TEWL results independently conducted and adjudicated the food challenge outcomes,” Freigeh said.
The mean baseline TEWL for the full cohort was 11.93 g/m2/hour. Means also included 11.63 g/m2/hour for women and 12.06 g/m2/hour for men, which was not a significant difference, the researchers said.
Additionally, means included 12.05 g/m2/hour for white patients, 9.8 g/m2/hour for Black patients, 11.92 g/m2/hour for Hispanic patients and 11.52 g/m2/hour for Asian patients. These differences also were not significant, Freigeh said, although he characterized the lower mean among Black patients as a trend.
There were inverse correlations between baseline TEWL and age (r = –0.138; P = .03), which Freigeh said has been reflected in other literature, and BMI (r = –0.168; P = .01), which has not been studied as much in relation to TEWL.
The cohort included 38 patients who experienced a clinically defined reaction during their OFC, with non-significant correlations between baseline TEWL values and greater reaction severity.
Specifically, patients with grade 1 reactions on the Consortium for Food Allergy Research (CoFAR) scale had a mean baseline TEWL value of 11.56 g/m2/hour. Those with grade 2 reactions had a mean baseline of 12.36 g/m2/hour. Patients whose reactions were grade 3 had a mean baseline of 15.09 g/m2/hour.
“There were no CoFAR 4 or 5 reactions in the study,” Freigeh said.
Further, participants with no reaction had a mean baseline of 11.68 g/m2/hour, which the researchers contrasted with those patients with CoFAR grade 3 reactions.
“Again, we see a non-significant increase in baseline TEWL, although here the P value is .06, indicating a much closer approach to significance,” Freigeh said. “We definitely do see a trend here.”
Those who experienced clinical anaphylaxis, with a CoFAR grade higher than 2, had a mean of 13.01 g/m2/hour.
“The anaphylaxis had a higher baseline TEWL, though again, this was not significant,” Freigeh said.
The study also included 20 patients who reacted during 49 OFCs for peanut. A multiple logistic regression model including TEWL, peanut wheal, total peanut IgE and peanut Ara h2 found a significant positive association between baseline TEWL and reaction status (OR = 1.225; P = .03).
“This represents very positive preliminary data,” Freigeh said.
Freigeh said that he and his colleagues plan to add more participants to the study, including more patients who experienced reactions during the OFCs, to solidify the trends in this data.
“Hopefully, this can serve as one piece of the overall evaluation of a patient for food challenges,” Freigeh said. “If we can find ways to make them more accessible and safe, that would benefit patients overall.”