Tell your doctor right away if you experience any of the following serious side effects: 1  Swollen glands. 2  Swollen or infected hair follicles. 3  Rash. 4  Oozing, crusting, blistering, or other signs of skin infection. 5  Cold sores. 6  Chicken pox or other blisters. 7  Swelling of the arms, hands, feet, ankles, or lower legs.