How should I treat dyshidrosis?

Depends. It's important to remove or get away from the source, if possible. Wear gloves when washing dishes, etc. We usually treat with creams or ointments containing steroids (like Hydrocortisone or triamcinolone) and with moisturizing lotions. In severe cases, there are some oral medicines that may be of some benefit. If over the counter meds aren't working, see a doctor.