Many substances, including chemicals and metals, can cause skin reactions; careful handling and identification of allergens are crucial to prevent dermatitis.
Certain skin drugs and topical agents, including some natural extracts and fragrances, can cause allergic reactions. Some hair dyes and extensions, as well as minoxidil, a hair growth treatment, can also cause allergies. Botulinum toxin A can effectively reduce sweat but may have temporary side effects.