ORIGINAL ARTICLE

Asian Pacific Journal ofAllergy and Immunology

Component resolved diagnosis of walnut allergy
in young children: Jug r 1 as a major walnut allergen
Jeongmin Lee,* Kyunguk Jeong, Se-ah Jeon, Sooyoung Lee

Abstract
Background: Walnuts (WN) are one of the main causes of tree nut allergies. However, the potential value of component resolved diagnosis (CRD) for WN allergy is controversial.
Objective: We analyzed the clinical and immunological features of clinical WN allergy and the usefulness of CRD inyoung children.
Methods: Forty-one participants with a history of ingesting WN who were assessed for serum-specific IgE to WN(WN-sIgE) using CRD (ImmunoCAP ISAC 112) at the Department of Pediatrics in Ajou University Hospital were enrolled and their demographic profiles, clinical symptoms, and laboratory findings were evaluated.
Results: A total of 32 patients were diagnosed with clinical WN allergy, of which 31 had specific immunoglobulin E
antibodies to Jug r 1 (Jug r1-sIgE). The Jug r 1-sIgE levels were higher in WN-allergic patients than in WN-tolerant patients and significantly higher in patients with anaphylaxis than in the WN-tolerant patients. Receiver-operating characteristic curves demonstrated that the Jug r 1-sIgE level was much better in discriminating between clinical WN allergy
and WN tolerance in young children than the WN-sIgE level.
Conclusions: Jug r 1 is the major component allergen in young children with clinical WN allergy. To measure Jug r
1-sIgE appears to be a promising approach for both diagnosis and predicting severity in young children with a historyof suspected WN allergy.
Key words: Jug r 1, walnut, allergy, children, ISAC, component resolved diagnosis

Affiliation:
Department of Pediatrics, Ajou University School of Medicine, Suwon,
Korea

Corresponding author:
Sooyoung Lee
Department of Pediatrics, Ajou University School of Medicine, 164
Worldcup-ro, Yeongtong-gu 16499, Suwon, Korea
E-mail: jsjs87@ajou.ac.kr* Current address:
Department of Pediatrics, Yonsei University, Wonju College ofMedicine, Wonju, Korea

Introduction

Walnut (WN) is one of the many allergens responsible
for cases of tree nut (TN) allergy and can induce fatal allergic reactions.1-3 Based on a Korean survey performed in 2008,
no individual was documented to be allergic to WN.4 However, WN imports have quadrupled in the last 10 years,5 and
WN now ranks as the third most common food that induces anaphylaxis in Korean children.3,6 Nevertheless, there has
been minimal study on WN allergy in very young children todate.6-9
A double-blinded, placebo-controlled food challenge(DBPCFC) is the gold standard to confirm food allergies
but is contraindicated in patients with a previous history ofanaphylaxis. In fact, WN often induces severe allergic reactions that necessitate close supervision by experienced allergists during DBPCFC. In 2008, Maloney et al.10 investigateddiagnostic decision points (DDPs) for WN, indicating thatpatients with WN-specific immunoglobulin E (sIgE) levels
greater than 18.5 kU/L have a very high probability of experiencing a reaction to WN.
Recombinant technology now allows for the production ofcomponents of WN allergen that can be used for component
resolved diagnosis (CRD).11 CRD may be useful to identify
the most problematic allergens in patients with specific sensitization patterns and could help to distinguish anaphylaxis
190

Major walnut allergen in young children

Statistical analysis
Statistical analyses were performed using R version 3.0.2
software (R Foundation for Statistical Computing, Vienna,
Austria). Normality was tested, and P-values for continuous
variables were calculated using the Kruskall-Wallis test. Fisher’s exact test was performed to compare categorical variables.
Pearson correlation analysis was performed to analyze thecorrelation between WN-sIgE (kU/L) and Jug r 1-sIgE (ISU)concentrations. The best cutoff was found using receiver operation characteristic (ROC) curve analysis, and area undercurve values (AUCs) were compared using the Delong test. P< 0.05 was considered statistically significant.

from milder symptoms.7,12,13 At present, eight WN allergens
have been identified and characterized from English walnut(Juglans regia),14 three of which are available in the ImmunoCAP ISAC system (Thermo Fisher Scientific Inc., Uppsala, Sweden): 2S albumin seed storage protein (Jug r 1; 15–16
kDa), vicilin seed storage protein (Jug r 2; 44 kDa), andnon-specific lipid transfer protein (Jug r 3 or LTP; 6 kDa).
However, the specific allergens involved in the allergic response to WN were found to differ among patients and weredependent on age, geographic region, and pollinosis. Further,
the additional diagnostic value provided by CRD for WN allergy has proven to be controversial.11-13,15
Thus, the aim of this study was to investigate the clinicaland immunological characteristics of young Korean children
with clinical WN allergy to identify the major allergenic components recognized in this population. Furthermore, we investigated whether additionally performing CRD has greater
benefits for diagnosing WN allergy than simply measuring
crude WN-sIgE.

Results

Demographic and clinical characteristics of patients
Among the 41 patients, 32 had WN-sIgE ≥ 0.10 kU/L
(0.10-91.3 kU/L) and met the clinical diagnostic criteria for
WN allergy. The median age was 28 months, with a range of
5–108 months. Symptoms from exposure included anaphylaxis (Ana, n = 7), angioedema (Ang, n = 10), and urticaria (U,n = 15). Among the 7 patients with Ana, all patients showedskin rash and respiratory symptoms, and none of the patients
had digestive, circulatory, or neurologic symptoms. Two patients had other food allergies (pine nut and peanut, respectively). Among the 10 patients with Ang, the youngest was 8
months old, and developed hives and edema after consuming
ground walnut mixed in water. Ang patients were significantly
younger than the other symptom groups (p < 0.05). Amongthe 12 patients diagnosed with U, the youngest patient was
a 5-month-old breast milk-fed infant who had repeated skinrashes with wheals when the mother consumed WN whilebreastfeeding.
With regard to other allergic comorbidities, asthma waspresent in 3 Ana patients, 1 Ang patient, and 1 U patient,while allergic rhinitis was present in 4 Ana patients, 2 Ang
patients, and 1 U patient. AD was present in 4 Ana patients, 1
Ang patients, and 8 U patients.
Feeding history was taken from 21 patients. Fourteen(66.7%) patients were exclusively breastfed for the first fourmonths, 7 (50.0%) of whom experienced an allergic reaction
to WN on their first exposure.
Further, 7 children had WN-sIgE ≥ 0.10 kU/L (0.42-53.5
kU/L) but did not develop symptoms upon exposure (T). The
mean age of these children was 55 months, and 6 of those(85.7%) had an allergy to other foods. The comorbidity rate
for other food allergies was significantly higher among T patients (p < 0.05, Table 1).

Methods

Study population
Based on a retrospective review of medical records, 189
patients aged 12 years or younger who visited the Ajou University Hospital (Suwon, Korea) underwent the ImmunoCAP
test (Thermo Fisher Scientific Inc., Uppsala, Sweden) for WNsIgE levels between May 2010 and May 2015. Among thesepatients, the parents of 41 patients provided informed consent
to participate in additional serological analysis, and serum
samples were taken simultaneously and stored at −20°C.
The diagnostic criteria for clinical WN allergy were as follows:16 1) WN-sIgE ≥ 0.10 kU/L; 2) immediate reaction in theskin, gastrointestinal, or respiratory organs within 2 h of exposure; and 3) repeated experience or met the diagnostic criteria for anaphylaxis.17 Individuals with WN-sIgE ≥ 0.10 kU/L
but who were asymptomatic after consumption were classified
as tolerant (T). Moreover, three patients with atopic dermatitis(AD), WN-sIgE < 0.10 kU/L, and who were asymptomatic after exposure were included as the control (C) group. Urticaria
was defined as skin erythema including hives, and angioedema was defined as mucosa swelling with or without hives.
We excluded cases limited to the perioral area. Controls werescreened for those who were diagnosed with AD but not diagnosed with pollinosis.
The study was approved by the institutional review board
at Ajou University Medical Center (MED-KSP-12-381).
Microarray
CRD was performed on all patients using the commercially available immune solid-phase allergen chip (ISAC) immunoassay ImmunoCAP ISAC (CRD 112; Thermo Fisher Scientific Inc., Uppsala, Sweden) according to the manufacturer’s
guidelines and as reported previously.11 Data are expressed
as ISAC standardized units (ISU/L, ISU), and the decisionthreshold was set at 0.

Immunological characteristics of patients and the additional
diagnostic value of Jug r 1
The ImmunoCAP ISAC (CRD 112) assay indicated that
31 of the 32 clinical WN-allergic patients (96.9%) had specific IgE antibodies to Jug r 1 and only 1 (U-9) was positive
for Jug r 2-sIgE isolate. The comparison of the immunologicalfeatures in relation to clinical symptoms showed that the Jug r
1-sIgE concentration varied significantly between the groups(p < 0.05). It was higher in the Ana (12.9 vs 0.8; p < 0.05),
Ang (5.8 vs 0.8; p = 0.48), and U (6.4 vs 0.8; p = 0.60) group191

Asian Pac J Allergy Immunol 2021;39:190-196 DOI 10.12932/AP-161118-0443

Table 1. Comparison of patient characteristics among groups.
Group

Anaphylaxis(n = 7)

Angioedema(n = 10)

Urticaria(n = 15)

Tolerant(n = 7)P

Age(months; median, range)

41(15, 108)20.5(8, 32)

32(5, 58)55(16, 96)0.020

Female2 (28.6%)

5 (50.0%)

8 (53.3%)

0 (0.0%)

0.069

Male

5 (71.4%)

5 (50.0%)

7 (46.7%)

7 (100.0%)

Other FA

2 (28.6%)

0 (0.0%)6 (40.0%)

6 (85.7%)

0.002

Asthma3 (42.9%)

1 (10.0%)

1 (6.7%)2 (28.6%)

0.119

Atopic dermatitis

4 (57.1%)

1 (10.0%)

8 (53.3%)

3 (42.9%)

0.118

Allergic rhinitis

4 (57.1%)

2 (20.0%)

1 (6.7%)2 (2.0%)0.059

Jug r1-sIgE(ISU, median; IQR)

12.9
(11.8;19.4)

5.8(3.0; 9.5)

6.4
(1.8;13.3)

0.8(0.0; 3.9)

0.020

Jug r1-sIgE/WN-sIgE(median; IQR)

1.5
(0.9;2.7)

1.0(0.3; 2.2)0.8
(0.4;2.8)0.1(0.0; 0.7)

0.090

WN-sIgE(kU/L, median; IQR)

8.4
(4.5;20.2)

11.9(2.0;27.4)

7.3(1.0;18.8)

5.8(4.0;7.1)

0.640

Sex

Comorbidity

The p-values (p) for continuous variables were calculated by Kruskall-Wallis (post hoc) test and those for categorical variables were calculated by Fisher’s exact
test; p-values < 0.05 were considered statistically significant.
FA, food allergy; WN-sIgE, walnut-specific immunoglobulin E on ImmunoCAP; Jug r 1-sIgE, Jug r 1-specific immunoglobulin E on ImmunoCAP ISAC (CRD112); IQR, interquartile range(a) Jug r 1-sIgE (ISU)(b) WN-sIgE (kU/L)
100

30

*
75

20
50
10

25

0

0
Ana

Ang

U

T

Ana

Group

Ang

U

T

Group

Figure 1. Levels of specific IgE to (a) Jug r 1, and (b) walnut according to the clinical history of anaphylaxis (Ana), angioedema (Ang), urticaria (U), and tolerance (T). * p < 0.05
than in the T group (Figure 1, Table 1). In contrast, no statistically significant differences in the WN-sIgE concentration
were detected among those groups. In addition, the WN-sIgE
concentration of 23 out of 32 (71.9%) clinical WN-allergic
children was below DDP level (≤ 18.5 kU/L).
We further analyzed the ImmunoCAP ISAC results for legumes and TNs in 32 clinically WN-allergic patients. All patients were sensitized to the storage protein of WN, and none
was exclusively sensitized to the LTP antigen, Jug r 3. Fifteen
patients (46.9%) were co-sensitized to more than one storage

protein. The protein with the highest positivity was the soy
storage protein Gly m 6 (n = 8, 25.0%), followed by hazel(Cor a 9, n = 7, 21.9%) and peanut (Ara h 2, n = 6, 18.8%;
Figure 2). Only two patients (37 months and 66 months old)
were co-sensitized to PR-10, and both had a history of pollen food syndrome. Cross-reactive carbohydrates (CCD) were
negative in all patients. Meanwhile, six patients in the T group(85.7%) were co-sensitized to more than one storage protein.
Information on clinical hypersensitivity to other TNs was not
fully available for all patients.
192

HazelCor a 1

Soy

Glym 4PN

Ara h 8PN

Ara h 9WN

Jug r 3

SesameSes l 1Hazel

Cor a 9

6.3%

6.3%

15.7%

21.9%

Ana o 2

15.7%

Soy

Glym 6

Soy

Glym 5PN

Ara h 6PN

Ara h 3PN

Ara h 2PN

Ara h 1WN

Ber e 1

Jug r 2WN

Storage protein

Brazil nut Cashew

LTP

PR-10

Major walnut allergen in young children

Jug r 1

6.3%

25%

9.4%

15.7%

6.3%

18.8%

12.5%

18.8%

96.9%

0

10

20

30

40

50

60

70

80

90

100

Figure 2. IgE to peanut, soy, and tree nuts detected in clinically walnut allergic children (n = 32) determined by ImmunoCAP ISAC (CRD 112).

193

Asian Pac J Allergy Immunol 2021;39:190-196 DOI 10.12932/AP-161118-0443

Jug r 1-sIgE (ISU)

30

20

10

r = 0.468 (CI 0.187-0.678)
P = 0.002

0
0

25

50
WN-sIgE (kU/L)

75

100

Figure 3. Correlation between walnut-specific IgE measured on ImmunoCAP, and Jug r 1-specific IgE measured on ImmunoCAP ISAC (n = 39).
Jug r 1-sIgE, Jug r 1-specific immunoglobulin E (ISU); WN-sIgE, walnut-specific immunoglobulin E (kU/L); CI, confidence interval.
1.0

Sensitivity

0.8

0.6

0.4

0.2

Jug r 1-sIgE (ISU)Jug r 1/WN
WN-sIgE (kU/L)

0.0
1.0

0.8

0.6
0.4
Specificity

0.2

0.0

Best cut off

Sensitivity (%)

Specificity (%)

PPV (%)NPV (%)

AUCs

p-value

WN-sIgE (kU/L)

5.96

85.71

46.88

6.2

73.9

0.563

0.592

Jug r 1-sIgE (ISU)

4.21

57.14

96.87

8.8

20.0

0.788

0.017

Jug r 1/WN

0.28

57.14

93.75

9.1

33.3

0.781

0.013

Components

Figure 4. Receiver-operating characteristic curves of IgE specific to Jug r 1 and ratio of Jug r 1/walnut-specific IgE comparedwith the specific IgE to crude walnut extract with regard to the ability to discriminate between an allergy and tolerance towalnut. AUCs, area under the curve values.

194

Major walnut allergen in young children

A positive, significant correlation between Jug r 1-sIgE
and WN-sIgE levels was found (r = 0.468; CI 0.187-0.678, p <0.05; Figure 3). The ROC curves showed that the Jug r 1-sIgE
measurement was better than the WN-sIgE measurement in
discriminating between clinical WN allergy and WN tolerance in young children (AUC = 0.788, p < 0.05; Figure 4).

It is also noteworthy to consider the history of patients
who experienced WN allergies on their first exposure. Basedon the experience of a patient (Ang-2) who never ingested
WN and did not have AD but had a WN-allergic reaction at
8 months of age with a WN-sIgE level of 30.0 kU/L. In addition, we found that approximately 50% of the patients withclinical WN allergy were already poly-sensitized to numerous
allergens other than WN, and the majority of them had no
previous history of ingestion. We considered that allergy prevention by early introduction might not only be necessary formoderate-to-severe AD patients and the factors affecting individual variations must be studied further.
The T group showed a high rate of other food allergies
and had a significantly lower Jug r 1-sIgE concentration.
Therefore, WN and wide-ranging TN avoidance guidancemust not be given to young children with positive results ofserum study only, especially, when their WN-sIgE level is ≥0.10 kU/L with a low Jug r 1-sIgE concentration, and they
have already been diagnosed with a soybean or peanut allergy. For the purpose of screening sensitization to the other treenuts, multiplex component-based allergen microarray would
be particularly useful for infants with moderate to severe AD,
for whom skin tests are practically difficult. Many of our patients were breastfed or on a mixed-fed diet, which may havecontributed to the sensitization, but transcutaneous sensitization through AD as well as co-sensitization due to cross-antigenicity are also possible.18-20 Additional studies are needed
to provide more accurate diet guidance and, despite practicalchallenges, a definitive diagnosis based on an OFC appears tobe crucial before providing avoidance.
This study has some limitations that should be discussed.
The major limitation of this study was its retrospective design.
Moreover, the study was based on self-reported history of allergic reactions, and the oral food challenge test was not conducted in most of patients. However, the results of this study
are noteworthy, considering that no previous studies havebeen conducted with CRD for very young children. The median age of our subjects was far lower than that in previous
studies, and thus, the underlying diseases were considerably
different from those in previous studies, which was reflectedin the result of the CRD. Moreover, we recruited participants
based on real-world data according to the level of exposureand symptoms, and that heavy exposure tended to occur in
one event. In contrast, in other studies, participants were
gradually exposed to WN by OFC.
In conclusion, measurement of Jug r 1-sIgE on very young
patients with suspected WN allergy could be beneficial for diagnosis and severity assessment, because these patients have ahigher specific IgE level to this component than WN-tolerant
patients and, furthermore, anaphylaxis patients have a significantly higher level than the tolerant patients.

Discussion

To our knowledge, this is the first study to investigate thevalue of CRD for WN allergy in very young children. Although oral food challenge (OFC) testing remains vital for adefinite diagnosis, parents often disagree with OFC using nuts
in very young children. Consequently, definitive diagnosis
is often delayed, which hinders research progress. However,since we have occasionally treated clinically WN-allergic patients, we aimed to explore the benefit of CRD among suchyoung patients for whom the OFC is practically difficult. Furthermore, we examined co-sensitization profiles of other nuts
prior to ingestion.
To date, there have been three studies on CRD for WN
allergy in older children.7,12,13 In 2014, a study was conducted
on 45 children (mean age: 8 years) in Northern Italy,13 showing a higher percentage of Ana patients who were positive for
Jug r 1-sIgE and Jug r 2-sIgE, when compared with those with
mild-moderate WN allergy. In our study, only the Jug r 1-sIgE
level was higher in WN-allergic patients than in tolerant patients and this level was significantly higher among patientswith anaphylaxis than among patients with WN tolerance,
which suggested an association with severity. Our observationthat patients with anaphylaxis had higher Jug r 1-sIgE levels may be explained by the fact that it is specific to a storage protein that contributes to the severe systemic response.
However, considering the finding of earlier research that Jug
r 1-sIgE level was not associated with the severity of allergic
reactions, there is a need to examine whether our observationis specific to the age group examined in this study.
In a 2016 British study,12 although the Jug r 1-sIgE level
was significantly higher than that among tolerant children, theAUC value was similar to that for WN-sIgE. A recent Japanese study6 administered an OFC to 108 children (medianage of 6–7 years) and found higher WN-sIgE and Jug r 1-sIgE
concentrations among the WN allergy group than among thetolerant group. In contrast to the British and Japanese studies,
the WN-sIgE concentrations in our study did not discriminate across groups, and the AUC of WN-sIgE was far weaker
than that of Jug r 1-sIgE. This difference may be attributable
to the fact that the clinical and immunological features offood allergy depend on age and region. Furthermore, in thisstudy, when the DDP of WN-sIgE was set as 18.5 kU/L, 71.9%
of clinically allergic patients were falsely predicted as tolerant;
thus, clinicians must be aware of this. ImmunoCAP-ISAC isexpensive and limited to research purposes in many countries, but the cost of selecting and implementing Jug r 1-sIgE
is similar to that of using WN-sIgE. Hence, based on our results, among the components of WN, to measure Jug r 1-sIgE
for diagnosis would be beneficial and cost-effective in this age
group.

Acknowledgements

We thank Thermo Fisher Scientific Inc. (Uppsala, Sweden)
for providing the kits used in component resolved diagnosis
of WN allergy. This research received no specific grant fromany funding agency.

195

Asian Pac J Allergy Immunol 2021;39:190-196 DOI 10.12932/AP-161118-0443

Disclosure statement

7.

Sato S, Yamamoto M, Yanagida N, Ito K, Ohya Y, Imai T, et al. Jug r 1
sensitization is important in walnut-allergic children and youth. J Allergy
Clin Immunol Pract. 2017;5:1784-6.
8. Lee JM, Kim EJ, Kwon DG, Lee SY. [Clinical characteristics of walnut
allergy and evaluation of cross-reactivity between walnut and peanut inchildren under 4 years of age]. Pediatr Allergy Respir Dis. 2011;21:261-8.
Korean.
9. Lee J, Jeong K, Jeon SA, Lee S. Immunoglobulin E-binding proteins ofcooked walnuts in Korean children. Allergy Asthma Immunol Res. 2018;
10:363-9.
10. Maloney JM, Rudengren MR, Ahlstedt S, Bock SA, Sampson HA. The use ofserum-specific IgE measurements for the diagnosis of peanut, tree nut, andseed allergy. J Allergy Clin Immunol. 2008;122:145-51.
11. Ferrer M, Sanz ML, Sastre J, Cuvillo A, Montoro J, Jauregui I, et al.
Molecular diagnosis in allergology: application of the microarray technique.
J Investig Allergol Clin Immunol. 2009;19:19-24.
12. Mew R, Borres M, Sjölander S, du Toit G. A retrospect study into the utilityof allergen components in walnut allergy. Pediatr Allergy Immunol. 2016;27:750-2.
13. Ciprandi G, Pistorio A, Silvestri M, Rossi GA, Tosca MA. Walnutanaphylaxis: the usefulness of molecular-based allergy diagnostics.
Immunol Lett. 2014;161:138-9.
14. Allergen Nomenclature [Internet]. Nebraska: WHO/IUIS Allergen
Nomenclature Sub-Committee; c2007-2019 [cited 2017 Nov 30]. Available
from: http://allergen.org/search.php?Species=Juglans%20regia
15. Blankestijn MA, Blom WM, Otten HG, Baumert JL, Taylor SL, Bruijnzeel-Koomen CA, e al. Specific IgE to Jug r 1 has no additional value comparedwith extract-based testing in diagnosing walnut allergy in adults. Allergy
Clin Immunol. 2017;139:688-90.
16. Park M, Kim D, Ahn K, Kim J, Han Y. Prevalence of immediate-type
food allergy in early childhood in Seoul. Allergy Asthma Immunol Res.
2014;6:131-6.
17. Simons FE, Ardusso LR, Dimov V, Ebisawa M, El-Gamal YM, Lockey RF, etal. World Allergy Organization. World Allergy Organization Anaphylaxis
Guidelines: 2013 update of the evidence base. Int Arch Allergy Immunol.
2013;162:193-204.
18. de Leon MP, Glaspole IN, Drew AC, Rolland JM, O’Hehir RE, Suphioglu C.
Immunological analysis of allergenic cross-reactivity between peanut andtree nuts. Clin Exp Allergy. 2003;33:1273-80.
19. Kulis M, Pons L, Burks AW. In vivo and T cell cross-reactivity between
walnut, cashew and peanut. Int Arch Allergy Immunol. 2009;148:109-17.
20. Clark AT, Ewan PW. The development and progression of allergy tomultiple nuts at different ages. Pediatr Allergy Immunol. 2005;16:507-11.

The authors declare that the ISAC CRD kit was donatedby Thermo Fisher Scientific Inc. (Uppsala, Sweden). There areno other conflicts of interest related to this work.

Author Contributions
•
•
•
•
•
•
•

Conceptualization: Sooyoung Lee
Data curation: Se-ah Jeon, Jeongmin Lee
Formal analysis: Jeongmin Lee, Kyunguk Jeong
Methodology: Sooyoung Lee, Jeongmin Lee
Validation, Investigation: Se-ah Jeon, Jeongmin Lee
Writing original draft: Jeongmin Lee
Review and editing: Kyunguk Jeong, Jeongmin Lee,
Sooyoung Lee

References
1.

2.
3.

4.
5.

6.

Le TM, Lindner TM, Pasmans SG, Guikers CL, Van Hoffen E, Bruijnzeel‐Koomen CA, et al. Reported food allergy to peanut, tree nuts and fruit:comparison of clinical manifestations, prescription of medication andimpact on daily life. Allergy. 2008;63:910-6.
McWilliam V, Koplin J, Lodge C, Tang M, Dharmage S, Allen K. The
prevalence of tree nut allergy: A systematic review. Curr Allergy Asthma
Rep. 2015;15:54.
Lee SY, Ahn K, Kim J, Jang GC, Min TK, Yang HJ, et al. Korean Academyof Pediatric Allergy and Respiratory Diseases Food Allergy and Atopic
Dermatitis Study Group. A multicenter retrospective case study ofanaphylaxis triggers by age in Korean children. Allergy Asthma Immunol
Res. 2016;8:535-40.
Lee SY, Kim KW, Ahn K, Kim HH, Pyun BY, Park YM, et al. [Consumer’s
use and satisfaction of allergic food labels]. Pediatr Allergy Respir Dis.
2011;21:294-301. Korean.
Korea Custom Service [Internet]. Seoul: The Korea Custom Service; c2013[cited 2018 Oct 30]. Tree nut import trends in 10 years; [about 9 screens].
Available from: http://www.customs.go.kr/kcshome/main/search_idol.do?query=%EA%B2%AC%EA%B3%BC%EB%A5%98&queryText=%EA%B2%AC%EA%B3%BC%EB%A5%98&notWord=&selZone=&selDate=ALL&beginDate=&endDate=&date1=&date2=&cateCode=0&
sortSpec=date&docStart=11
Jeong K, Lee SY, Ahn K, Kim J, Lee HR, Suh DI, et al. A multicenter study
on anaphylaxis caused by peanut, tree nuts, and seeds in children andadolescents. Allergy. 2017;72:507-10.

196