What would cause the skin on my hands to crack and split every winter?

Hand eczema. Hand eczema, also known as dyshidrosiform or dyshidrotic eczema is an inflammatory condition that can manifest as tiny deep blisters, skin thickening, cracking (called fissures), redness, itching, and peeling. Topical steroid ointments or creams are commonly prescribed. Over-the-counter remedies include heavy emollients, "bag balm", and barrier creams.