A total of 79 nickel-sensitive patients (65 women, 14 men) were examined with regard to a present or past eczema corresponding to contact with metallic buttons in blue jeans; 63% of the women and 64% of the men had or had had eczema of this kind. Among 40% of the women below 30 years this was the primary site of manifestation. The seriousness of this sensitivity is illustrated by the fact that two-thirds of the nickel sensitive patients with button dermatitis had or had had eczema of the hands. The conclusion is that blue jean buttons should be made of a material which does not contain nickel, for instance zinc alloys which are presently used for some metallic buttons, or they should be designed in such a way that the button does not directly contact the skin.