If you think your laundry detergent might be contributing to your dry itchy skin problem, look for a laundry detergent that says "hypoallergenic" on the label. To combat dry itchy skin, use a skin moisturizer, but for best results, don't simply slather lotion all over your dry body. The moisturizer can be any lotion or oil that will seal the water into your dry itchy skin so that it can't dehydrate again as easily.
One of the most popular products available today is dry body oil spray. Most women prefer dry body oil spray to sloppy and body gels, creams and other remedies. Dry body oil spray is best applied right after a shower or bath as mentioned above, when your skin is still slightly wet.
Generally, dry skin is caused by a lack of lubrication resulting from clogged or damaged oil glands. The best lotion for dry skin will work to open the oil glands and replenish lost moisture. Avoid washing with tap water as most tap water is treated with chemicals which can affect the skin. Even the best dry skin lotion will only be able to help so much if you aren't watching what you eat and drink.