The only way to eliminate the possibility of irritation caused by the aluminum in antiperspirants is to avoid the product, according to About.com. Severe reactions to deodorants may require treatment by a medical professional.
About.com notes that if someone suffers from a reaction to an antiperspirant, she may have to have patch testing done by an allergist to determine whether the irritation is being caused by the aluminum in the antiperspirant, or by fragrances or other chemicals contained in it. If a fragrance is identified as the cause, the person can switch antiperspirants. If aluminum is the issue, she should stop using that antiperspirant. If the person in question is already suffering from swelling, hives or other reactions to the product, topical corticosteroids may be used to treat the reaction. Dermatitis, as well as fungal and yeast infections, may also cause underarm irritation.
According to Good Housekeeping, alternative deodorants may provide natural options to replace traditional stick or spray antiperspirants. Some brands include Dr. Hauschka, Weleda, Erbaviva, Aubrey Organics, Bubble and Bee, Lafe's, and Miessence. About.com also mentions Crystal Body Deodorant, which is based on zeolite crystals, as another possibility. While all these products are deodorants rather than antiperspirants, most use no aluminum, antibacterials, fragrances, parabens, PEGs, petrochemicals or other synthetic ingredients.