Closed-cell pimples that turn into hard bumps can be improved by medication and physical therapy. 1. Medication: You can apply topical medication such as retinoic acid ointment and benzoyl peroxide ointment on the affected area, or take oral medication such as isotretinoin, which can soften the hard pimples and make them disappear gradually. 2. Physical therapy: laser and other photoelectric treatment can be used, mainly by using photothermal effect to destroy the sebaceous glands that produce exuberant secretion and improve the symptoms. It can also stimulate the regeneration of collagen in the deeper layers of the skin to improve skin quality. In addition, it is recommended that patients with closed-cell acne become hard pimples go to the hospital in time and follow the doctor’s instructions for treatment to avoid delaying the condition.