Hydrate Your House and Body
Dry indoor air can irritate your skin and your sinuses, so keep indoor air moist. Install a whole-house humidifier on your furnace or use a room humidifier or two. Keep humidity set between 30% and 50%. If you use a room humidifier, clean it often so mold or mildew don't build up.
Keep your skin hydrated from the inside out by getting enough healthy fats and vitamins. Fatty acids like omega-3s help make up your skin's natural, moisture-retaining oil barrier. Too few of these healthy fats can result in dry, itchy skin. You can get omega-3s from seafood (especially salmon and tuna), as well as flaxseed, walnuts, and canola oil.
Foods rich in vitamins also help keep your skin moist and healthy. Eat plenty of poultry, fish, whole grains, and beans.