Table 1.

Case reports of new contact allergens identified in terms of biocides (preservatives, but also including herbicides and pesticides) other than isothiazolinones. F, female, M, male; age in parentheses. NT, not tested. Patch tests usually read on day (D)3, D4, or D7.

Substance	Patients	Clinical Problem	Patch Test	Comment	Ref.
Benzoic acid, Sodium benzoate	M (12)	Cheilitis caused by Coca Cola and canned beans	Sodium benzoate 5% pet: ++, benzoic acid 2%: +		[244]
Didecyldimethylammonium chloride	12	Dermatitis	0.1% pet.: 2 relevant pos.	Several false-positive; test dilution series	[245]
Pethoxamid	M (49) production worker	Acute dermatitis after accidental exposure	0.01% +, 0.03–1% +++	Agricultural workers may be at risk, too	[246]
Polyhexamethylene biguanide	F (59)	Chronic leg ulcer, multiple sensitization, dermatitis after wound gel	PHMB 5% aq. ++		[247]
Polyhexamethylene biguanide	F (46)	Hand dermatitis after contact lens cleaning solution	PHMB 5% aq. +	Found In 16/35 contact lens solutions	[248]
Polyhexamethylene biguanide	M (13)	Peristomal dermatitis due to foam dressing	PHMB 5% aq. +	Also allergic to alkyl glucosides	[249]
1-Propanol	F (56) nurse	Hand dermatitis after Sterillium®	1-propanol 10% aq.: +	2-Propanol: neg.	[250]
Sodium metabisulfite	357/12,156	Various products, e.g., ophthalmic	1% pet.	40% clinically relevant	[251]