Change in Peanut Skin Prick Testing Over Time in Infants at Risk for Food Allergy Who - PowerPoint Presentation

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Change in Peanut Skin Prick Testing Over Time in Infants at Risk for Food Allergy Who Continue to Avoid Peanut Morgan A. Amigo, BA1, Irene Mikhail, MD1,2, Eric M. McLaughlin, MS3, David R. Stukus, MD1,2, and Benjamin T. Prince MD, MSCI1,2 1The Ohio State University College of Medicine, Columbus, OH, 2Nationwide Children’s Hospital, Columbus, OH; 3The Ohio State University, Department of Biomedical Informatics

BACKGROUND

METHODS

RESULTS

CONCLUSIONS

REFERENCES

In 2017, guidelines for the prevention of peanut allergy in the US recommended the early introduction of peanut for all infants, with risk stratification for those who are at high-risk for developing peanut allergy (moderate-severe eczema and/or egg allergy) using peanut specific

IgE

quantification.

1

Data from our institution showed that 68% of at risk infants for peanut allergy qualify for home introduction; however, of those requiring in office oral food challenge (OFC), 91% were deferred to a subsequent visit, and 40% of deferred challenges never returned.2Cases at our institution of deferred OFCs having significant increases in peanut skin prick test (SPT) wheel diameter at follow up were observed.While many infants with a positive SPT may tolerate peanut, a larger peanut SPT wheal diameter is associated with a higher probability of failed oral food challenge with a wheal size of ≥8mm being the 95th PPV for having peanut allergy.3-4

HYPOTHESIS

In this at risk population of infants, the peanut SPT wheel size is dynamic and changing with time, and there may be a critical window in time for the successful introduction of peanut.

Figure 1. Change in peanut skin prick test wheal size in all patients at risk for peanut allergy.  

Table 1. Patient demographics.

Table 2. Change in peanut skin prick test (SPT) wheal size group between SPT1 and SPT2 in patients at high risk for peanut allergy.

Figure 2. Peanut skin prick test (SPT) wheal size increases over time in infants at risk for peanut allergy.

A. Among the 45 patients with SPT1 wheal of <8mm there was a statistically significant difference between SPT1 and SPT2 with an average increase of 2mm. B. Among the 26 patients with SPT1 wheal of 0mm there was a statistically significant difference between SPT1 and SPT2 with an average increase of 2.5mm. **p=0.0014, ***p=0.0010 calculated by Wilcoxon matched-pairs signed rank test.

Figure 3. Egg sensitization and eczema severity may be risk factors for increasing peanut skin prick test (SPT) wheal size in infants at risk for peanut allergy. A-C. Comparisons made using the Wilcoxon rank-sum test.   

SPT2 Wheal SizeSPT1 Wheal Size0-4 mm5-7 mm≥8 mmTotal0-4 mm24 (63.2%)11 (28.9%)3 (7.9%)385-7 mm2 (3.9%)3 (5.9%)2 (3.9%)7≥8 mm0 (0%)1 (16.7%)5 (83.3%)6Total26 (60%)15 (29.4%)10 (19.6%)51

Number51Male No. (%)29 (56.9)Race, No. (%): White30 (58.8) Black12 (25.5) Other8 (15.7)SPT 1 Mean Age (mo.)7.7 (5-12)SPT 2 Mean Age (mo.)13.6 (5-24)Mean Time Between SPTs (mo.)5.8Eczema50 (98)Eczema Severity No. (%): None-Mild 17 (33.3) Moderate34 (66.7)Egg Sensitization No. (%)33 (64.7)Any Food Allergy No. (%)43 (82.4)

SUMMARY

A.

B.

Infants at risk for peanut allergy who continued to avoid peanut had a significant increase in their peanut skin prick test (SPT) wheal diameter with an increase of 2mm over a mean duration of 5.8 months.

Infants at risk for peanut allergy with no evidence of peanut sensitization at initial evaluation had a significant increase in their peanut SPT wheal diameter with an increase of 2.5mm over a mean duration of 6 months.

There was a trend for significance of infants with egg sensitization and more severe eczema having a greater change in peanut SPT wheal size between SPT1 and SPT2.In our population of infants at risk for peanut allergy, gender and race did not appear to effect peanut SPT wheal size between SPT1 and SPT2.

Togias A, Cooper SF, Acebal ML, Assa'ad A, Baker JR, Beck LA, et al. Addendum guidelines for the prevention of peanut allergy in the United States: Report of the National Institute of Allergy and Infectious Diseases-sponsored expert panel. J Allergy Clin Immunol. 2017 Jan;139(1):29–44 Stukus DR, Prince BT, Mikhail I. Implementation of Guidelines for Early Peanut Introduction at a Pediatric Academic Center. J Allergy Clin Immunol. 2018;Sep - Oct;6(5):1784-1786 Peters RL, Allen KJ, Dharmage SC, Tang MLK, Koplin JJ, Ponsonby A-L, et al. Skin prick test responses and allergen-specific IgE levels as predictors of peanut, egg, and sesame allergy in infants. J Allergy Clin Immunol. 2013 Oct;132(4):874–80 Koplin JJ, Peters RL, Dharmage SC, Gurrin L, Tang MLK, Ponsonby AL, et al. Understanding the feasibility and implications of implementing early peanut intro- duction for prevention of peanut allergy. J Allergy Clin Immunol 2016;138: 1131-41.e2.

D.

C.

B.

A.

Peanut skin prick test (SPT) wheal size can increase over time in infants at risk for peanut allergy who are avoiding peanut, even if not initially demonstrating peanut sensitization.

Egg sensitization and eczema severity may be risk factors for increasing SPT wheal size in infants at risk for peanut allergy.

Our findings support that there may be a critical window in time for the successful introduction of peanut among infants at risk for developing peanut allergy.

In infants with peanut SPTs <8mm, it is important to introduce peanut in a timely manner.

A 5-year retrospective chart review was performed from April 2013 to April 2018 at Nationwide Children’s Hospital to assess changes in peanut SPT wheal diameter in infants.

Inclusion Criteria

: Any infant with physician diagnosed eczema and/or the presence of IgE food sensitization that had two peanut SPTs (SPT1 and SPT2) placed at separate time points during the first 24 months of life.Exclusion Criteria: Any infant with a history of peanut ingestion prior to either SPT.Food sensitization was defined as having a food specific IgE of >0.35kU/L or a food specific SPT average wheal diameter of ≥3mm.Mild eczema was defined as over the counter topical steroid use where moderate eczema was defined as use of low to medium potency topical steroid.Patients with SPT1 wheal size of ≥8mm (6 total) were considered peanut allergic and removed from analysis.