In general, deodorants and Anti-perspirants are considered to be safe products. However allergic reactions to deodorants and Anti-perspirants can occur in people with very sensitive skin.
Such a reaction towards deodorants or Anti-perspirants may occur suddenly, upon first application, or even after months of exposure.
There are a number of chemicals that can be responsible for contact dermatitis from deodorants and Anti-perspirants
For example, Eucerin Deodorant Sensitive Skin, available as a Roll-On is free from irritants such as alcohol, perfume, colorants and preservatives so it is skin-friendly.
If you are experiencing contact dermatitis* from a deodorant or Anti-perspirant, stop using your deodorant right away to avoid further exposure to irritants or allergens.