Risk Factors for Severe Seafood Allergy Among Adults in an Urban City in Vietnam

Figures & data

Table 1 Demographic Characteristics of the Study Subjects

		Convincing SFA (N=209)	Shellfish allergy^δ (N = 197)	Fish Allergy^δδ (N = 37)	Only Shellfish Allergy^δδδ (N=173) (1)	Only Fish Allergy^δδδδ (N=11) (2)	Both shellfish and Fish Allergy^δδδδδ (N=23) (3)	P values between Groups	P values between (1) and (2)	P values between (1) and (3)
Age (years-old)*		21 ± 2.91	21 ± 2.83	22 ± 3.72	21 ± 2.77	21 ± 3.00	22 ± 3.65	0.309	0.19	0.46
Gender (N, %)	Male	72 (34.45%)	95 (48.22%)	11 (29.73%)	87 (50.29%)	3 (27.27%)	15 (65.22%)	0.15	0.21	0.19
	Female	137 (65.55%)	102 (51.78%)	23 (62.16%)	86 (49.71%)	8 (72.73%)	15 (65.22%)
Income (millions VND/ months) (N, %)	< 0.9	49 (23.44%)	47 (23.86%)	9 (24.32%)	41 (23.7%)	4 (36.36%)	6 (26.09%)	0.481	0.16	0.98
	0.9 – < 1.3	0	0 (0%)	0 (0%)	0 (0%)	0 (0%)	0 (0%)
	1.3 – < 2.2	32 (15.31%)	28 (14.21%)	6 (16.22%)	25 (14.45%)	3 (27.27%)	3 (13.04%)
	2.2 – < 5.0	71 (33.97%)	63 (31.98%)	11 (29.73%)	56 (32.37%)	4 (36.36%)	7 (30.43%)
	≥ 5.0	57 (27.27%)	59 (29.95%)	8 (21.62%)	52 (30.06%)	0 (0%)	8 (34.78%)
Housing (N, %)	House	72 (34.45%)	66 (33.5%)	10 (27.03%)	60 (34.68%)	3 (27.27%)	6 (26.09%)	0.49	0.58	0.28
	Apartment	32 (15.31%)	33 (16.75%)	3 (8.11%)	30 (17.34%)	1 (9.09%)	2 (8.7%)
	Rental housing	105 (50.24%)	98 (49.75%)	22 (59.46%)	83 (47.98%)	7 (63.64%)	15 (65.22%)

Notes: Data are presented as N (%). P values were calculated by Pearson’s chi square or Fisher’s exact test.* P values were presented as median ± SD, and were calculated by Mann–Whitney U-test. Values in bold indicate significant P values. ^δ Shellfish allergy: the respondents who had reported reactions to any shellfish species regardless of any reactions to fish among the convincing allergy group. ^δδFish allergy: the respondents who had reported reactions to any fish species regardless of any reactions to shellfish among the convincing allergy group. ^δδδ Only shellfish allergy: the respondents who had reported reactions to any shellfish species but without any reactions to fish among the convincing allergy group. ^δδδδ Only fish allergy: the respondents who had reported reactions to any fish species but without any reactions to shellfish among the convincing allergy group. ^δδδδδ Both shellfish and fish allergy: the respondents who had reported reactions to both shellfish and fish among the convincing allergy group.

Figure 1 Coexisting allergy between seafood species among participants with convincing allergy. In each cell, the correlation of subjects who were allergic to each column had comorbid allergy to each row, and in reverse. Correlation was calculated by Pearson correlation coefficient. *P<0.05, **P<0.01.

Table 2 History of Comorbid Allergic Diseases Among Subjects with Convincing Allergy

	Convincing Allergy (N=209)	Shellfish Allergy^δ (N = 197)	Fish Allergy^δδ (N = 37)	Only Shellfish Allergy^δδδ (N=173) (1)	Only Fish Allergy^δδδδ (N=11) (2)	Both Shellfish and Fish Allergy^δδδδδ (N=23) (3)	P values between Groups	P values between and (2)	P values between (1) and (3)
Asthma (N, %)	20 (9.57%)	18 (9.14%)	3 (8.11%)	19 (10.98%)	2 (18.18%)	1 (4.35%)	0.42	0.36	0.48
Atopic dermatitis (N, %)	52 (24.88%)	49 (24.87%)	13 (35.14%)	40 (23.12%)	2 (18.18%)	10 (43.48%)	0.10	1	0.044
Allergic rhinitis (N, %)	84 (40.19%)	81 (41.12%)	13 (35.14%)	72 (41.62%)	2 (18.18%)	10 (43.48%)	0.40	0.21	1
Rash/urticaria (N, %)	97 (46.41%)	89 (45.18%)	33 (89.19%)	76 (43.93%)	8 (72.73%)	14 (60.87%)	0.06	0.07	0.18
Anaphylaxis (N, %)	21 (10.05%)	21 (10.66%)	3 (8.11%)	19 (10.98%)	0 (0%)	4 (17.39%)	0.34	0.61	0.49
Peanut/nuts allergy (N, %)	8 (3.83%)	8 (4.06%)	0	5 (2.89%)	0 (0%)	4 (17.39%)	0.06	0.74	0.018
Other food allergy (N, %)	26 (12.44%)	25 (12.69%)	10 (27.03%)	14 (8.09%)	1 (9.09%)	9 (39.13%)	0.001	0.97	<0.001

Notes: Data were presented as N (%). P values were calculated by χ2 Pearson or Fisher’s exact test. Values in bold indicate significant P values. ^δ Shellfish allergy: the respondents who had reported reactions to any shellfish species regardless of any reactions to fish among the convincing allergy group. ^δδFish allergy: the respondents who had reported reactions to any fish species regardless of any reactions to shellfish among the convincing allergy group. ^δδδ Only shellfish allergy: the respondents who had reported reactions to any shellfish species but without any reactions to fish among the convincing allergy group. ^δδδδ Only fish allergy: the respondents who had reported reactions to any fish species but without any reactions to shellfish among the convincing allergy group. ^δδδδδ Both shellfish and fish allergy: the respondents who had reported reactions to both shellfish and fish among the convincing allergy group.

Figure 2 (A) Age of onset of SFA symptoms and (B) age of first introduction of shellfish/fish among convincing allergy subjects. The percentage of subjects who had persistent reactions after (C) shellfish or (D) fish consumption. *P <0.05. P values were calculated by Pearson’s chi-square.

Table 3 Prevalence of Symptoms Among the Convincing Allergy Group

	Convincing Allergy (N = 209)	Shellfish Allergy^δ (N = 197)	Fish Allergy^δδ (N = 37)	Only Shellfish Allergy^δδδ (N=173) (1)	Only Fish Allergy^δδδδ (N=11) (2)	Both Shellfish and Fish Allergy^δδδδδ (N=23) (3)	P values between Groups	P values between (1) and (2)	P values between (1) and (3)
Rash/urticaria	158 (75.60%)	146 (74.11%)	32 (86.49%)	124 (71.68%)	9 (81.82%)	22 (95.65%)	0.035	0.73	0.01
Cough	145 (69.38%)	137 (69.54%)	19 (51.35%)	118 (68.21%)	5 (45.45%)	21 (91.3%)	0.027	0.30	0.026
Lips/Face swelling	89 (42.58%)	87 (44.16%)	9 (24.32%)	71 (41.04%)	2 (18.18%)	15 (65.22%)	0.022	0.21	0.042
Itchy throat/mouth	92 (44.02%)	85 (43.15%)	13 (35.14%)	74 (42.77%)	2 (18.18%)	14 (60.87%)	0.11	0.19	0.19
Flush	66 (31.58%)	60 (30.46%)	9 (24.32%)	54 (31.21%)	3 (27.27%)	10 (43.48%)	0.47	1	0.25
Eye/eyelids swelling	53 (25.36%)	49 (24.87%)	9 (24.32%)	36 (20.81%)	3 (27.27%)	13 (56.52%)	0.002	0.70	0.002
Abdominal pain	50 (23.92%)	44 (22.34%)	10 (27.03%)	41 (23.7%)	4 (36.36%)	5 (21.74%)	0.59	0.47	1
Diarrhea	40 (19.14%)	35 (17.77%)	4/37 (10.81%)	35 (20.23%)	2 (18.18%)	5 (21.74%)	0.98	1	1
Vomit	27 (12.92%)	27 (13.71%)	1/37 (2.70%)	25 (14.45%)	0 (0%)	2 (8.7%)	0.32	0.37	0.75
Nasal congestion/runny nose	24 (11.48%)	24 (12.18%)	2/37 (5.41%)	16 (9.25%)	0 (0%)	8 (34.78%)	0.001	0.60	0.002
Throat choking	41 (19.62%)	38 (19.29%)	5 (13.51%)	33 (19.08%)	2 (18.18%)	5 (21.74%)	0.95	1	0.78
Wheezing/shortness of breath	30 (14.35%)	23 (11.68%)	3 (8.11%)	20 (11.56%)	2 (18.18%)	4 (17.39%)	0.66	0.62	0.50
Faint/dizziness	16 (7.66%)	10 (5.08%)	0 (0%)	10 (5.78%)	0 (0%)	1 (4.35%)	0.69	1	1
Loss of consciousness	5 (2.39%)	4 (2.03%)	0 (0%)	4 (2.31%)	0 (0%)	0 (0%)	0.67	1	1

Notes: Data were presented as N (%). P values were calculated by Pearson’s chi square or Fisher’s exact test. Values in bold indicate significant P values. ^δ Shellfish allergy: the respondents who had reported reactions to any shellfish species regardless of any reactions to fish among the convincing allergy group. ^δδFish allergy: the respondents who had reported reactions to any fish species regardless of any reactions to shellfish among the convincing allergy group. ^δδδ Only shellfish allergy: the respondents who had reported reactions to any shellfish species but without any reactions to fish among the convincing allergy group. ^δδδδ Only fish allergy: the respondents who had reported reactions to any fish species but without any reactions to shellfish among the convincing allergy group. ^δδδδδ Both shellfish and fish allergy: the respondents who had reported reactions to both shellfish and fish among the convincing allergy group.

Table 4 Characteristics of Behavior Towards Seafood Allergy

	Convincing Allergy (1)	Shellfish Allergy^δ (N = 197)	Fish Allergy^δδ (N = 37)	Only Shellfish Allergy^δδδ (N=173) (1)	Only Fish Allergy^δδδδ (N=11) (2)	Both Shellfish and Fish Allergy^δδδδδ (N=23) (3)	P values between Groups	P values between (1) and (2)	P values between (1) and (3)
No treatment	115 (55.02%)	102 (51.78%)	17 (45.95%)	97 (56.07%)	5 (45.45%)	13 (56.52%)	0.79	0.54	1
Antihistamine	84 (40.19%)	79 (40.10%)	16 (43.24%)	68 (39.31%)	4 (36.36%)	12 (52.17%)	0.49	1	0.06
Emergency/ Hospitalization	18 (8.61%)	18 (9.14%)	1 (2.70%)	15 (8.67%)	0 (0%)	2 (8.7%)	0.56	0.60	1
Steroid	19 (9.09%)	18 (9.14%)	5 (13.51%)	14 (8.09%)	1 (9.09%)	5 (21.74%)	0.14	1	0.06
Epinephrine	7 (3.35%)	6 (3.05%)	1 (2.70%)	6 (3.47%)	1 (9.09%)	0 (0%)	0.39	0.36	1
Asthmatic medications	5 (2.39%)	4 (2.03%)	2 (5.41%)	4 (2.31%)	1 (9.09%)	1 (4.35%)	0.39	0.27	0.48

Notes: Data were presented as N (%). P values were calculated by Pearson’s chi square or Fisher’s exact test. ^δShellfish allergy: the respondents who had reported reactions to any shellfish species regardless of any reactions to fish among the convincing allergy group. ^δδFish allergy: the respondents who had reported reactions to any fish species regardless of any reactions to shellfish among the convincing allergy group. ^δδδ Only shellfish allergy: the respondents who had reported reactions to any shellfish species but without any reactions to fish among the convincing allergy group. ^δδδδ Only fish allergy: the respondents who had reported reactions to any fish species but without any reactions to shellfish among the convincing allergy group. ^δδδδδ Both shellfish and fish allergy: the respondents who had reported reactions to both shellfish and fish among the convincing allergy group.

Table 5 Multivariate Logistic Regression Analysis of Severe Allergy to Shellfish or Any Seafood

	Any Seafood Allergy (N=209)		Shellfish^d (N=197)
	aOR (95% CI) (*)	P value	aOR (95% CI) (*)	P value
Age	0.99 (0.85–1.16)	0.94	0.99 (0.85–1.16)	0.89
Male	0.29 (0.12–0.69)	0.006	0.37 (0.16–0.89)	0.026
History of asthma	4.16 (1.31–13.27)	0.016	2.54 (0.79–8.19)	0.12
History of anaphylaxis	6.28 (2.08–19.03)	0.001	5.87 (1.96–17.64)	0.002
History of comorbid peanut/nut allergy	7.72 (1.58–37.74)	0.012	8.37 (1.69–41.20)	0.009
Allergy to ≥ 3 seafood species	4.49 (1.76–11.48)	0.002	5.86 (2.12–16.15)	0.001

Notes: (*) aOR, adjusted odd ratios for age and gender. Values in bold indicate significant P value.