In five patients developing axillary contact dermatitis subsequent to the use of an antiperspirant containing propantheline bromide patch testing was performed. Three patients reacted to propantheline bromide. The other two patients exhibited positive patch test reactions to the proprietary product; in these cases, the active ingredient was not tested individually. In all five patients, in addition to the antiperspirant, at least one other contact allergen was identified. In case of localized adverse reactions due to topical treatment of hyperhidrosis axillaris patch testing is recommended. If contact allergy to propantheline bromide is revealed, one should be aware of cross sensitization to methantheline bromide.