How To Cure Dry,itchy And Small Bumps On Skin?

Hi, my skin is usually normal and relatively fair throughout the year, but during winter and summer seasons my hands get "chapped" or dry. The skin on my hand varies during this time and will be as severe as cracking and rash-like in the winter, and is currently dry, itchy, and small bumps have appeared. What could be the cause of this, and what can I do to prevent it? A reply to this query will be much appreciated.