Simply put, tanning itch is caused by the process of regenerating skin cells to replace the skin cells that were damaged or destroyed while tanning. Because of this, tanning itch very rarely happens right after a tanning session; it can take 24-48 hours before the first signs of tanning itch occur.

Tanning itch doesn’t happen every time one goes tanning, nor does it happen after every sunburn. But while it can be somewhat unpredictable, the itch typically occurs when the body is not properly hydrated in the days before and the days after a tanning session. The drier the skin is before a tanning session and the less a person hydrates after a tanning session, the more likely that tanning itch becomes a factor.

The degree of the actual tan or burn doesn’t seem to matter has much as the amount of hydration a person does prior to and after the tanning process.

The regeneration of skin cells starts under the epidermis and then forces itself to the surface, repelling the dead and damaged skin, peeling it back. If the skin is extra dry, that regeneration causes an irritation that is extremely painful. And because the forming of the skin cells is happening below the surface, the normal routine of scratching the itch not only is ineffective in lessening the itch, but it also causes irritation of the surface layer. In general, it takes 24 hours for the worst of the tanning itch to pass and 48-72 hoursfor the itch to completely subside in lieu of the new skin.