Calamine lotion side effects on skin?

Not unless allergic: Other than relieving an itch, calamine lotion should not have any effect on the skin. It would be very unusual to be allergic to calamine lotion but it is theoretically possible, so if your skin seems more irritated, red, itchy or uncomfortable after using calamine lotion, stop using it and avoid it in the future. More likely would be effects from whatever rash you were using the calamine to treat.