Role of Patch Testing in Chronic Spontaneous Urticaria

Figures & data

Table 1 Patient Demographics and Clinical Characteristics

	CD Group (n = 680)	CSU Group (n = 134)	p-value
Age [years] (mean)	43.9	48	p<0.05
Gender [male] (%)	41%	23%	p<0.01
Atopic background [n] (%)	391 (58%)	60 (of 131^†, 46%)	p<0.05
Patients with positive reactions [n] (%)	251 (37%)	46 (34%)	p>0.05
Patients with relevant positive reactions [n] (%)	150 (22%)	4 (3%)	p<0.01

Notes: ^†Three patients had an unknown atopy status; p-value < 0.05 was considered statistically significant.

Abbreviations: CD, Contract Dermatitis; CSU, Chronic spontaneous urticaria; n, number.

Table 2 Ten Topmost Allergens Causing Reactions in the CD Group, and Their Respective Number of Reactions Causing in the CSU Group

Allergen	CD Group (n = 680)		CSU Group (n = 134)
	Reactions		Reactions
	Total	Relevant	Total	Relevant
Nickel	102 (15%)	22 (3.2%)	27 (20.1%)	2 (1.5%)
Methylchloroisothiazolinone/Methylisothiazolinone (MCI/MI)	38 (5.6%)	35 (5.1%)	5 (3.7%)	0 (0%)
Methylisothiazolinone	30 (4.4%)	29 (4.3%)	1 (0.7%)	0 (0%)
Fragrance Mix I	25 (3.7%)	14 (2.1%)	6 (4.5%)	0 (0%)
Myroxolon pereirae	24 (3.5%)	11 (1.6%)	2 (1.5%)	0 (0%)
Potassium dichromate	15 (2.2%)	8 (1.2%)	2 (1.5%)	1 (0.7%)
Thimerosal	15 (2.2%)	1 (0.1%)	0 (0%)	0 (0%)
Epoxy resin	12 (1.8%)	3 (0.4%)	1 (0.7%)	0 (0%)
Cobalt	12 (1.8%)	1 (0.1%)	4 (3%)	1 (0.7%)
p-Phenylene diamine (PPD)	11 (1.6%)	9 (1.3%)	3 (2.2%)	0 (0%)

Abbreviations: CD, Contract Dermatitis; CSU, Chronic spontaneous urticaria.