It could also be due to overuse of AC and heaters. If you have
blisters at tip of fingers and dry
skin then you need to rule out certain conditions such as diabetes, psoriasis, hypothyroidism, contact dermatitis, atopic dermatitis and malnutrition.
Generalized itching can be due to allergy. Common allergens are pollen, mold, dust, pet dander, synthetic fiber, food, cosmetics (powders, soaps, shampoos—see if anything was recently changed) or drugs.