The itching that occurs after shaving is primarily caused by irritation of hair follicles and the skin. When shaving, the razor cuts hair close to the skin, but hair continues to grow underneath. This can irritate the hair follicles and skin surface, leading to itchiness. Factors like using a dull razor, shaving dry skin, shaving too quickly, shaving against the direction of hair growth, or shaving sensitive areas can exacerbate this irritation. Additionally, razor burn and ingrown hairs (where hair grows back into the skin) contribute to itching and redness after shaving. Other causes include dry skin and contact with fabric or detergents immediately post-shave, which can further irritate the skin. Using harsh or scented soaps and shaving products can also dry out and irritate the skin, resulting in itching. In summary, itching after shaving is caused by hair follicle irritation, razor burn, ingrown hairs, dry skin, and external irritants from shaving products or fabric contact.