Acne is a chronic inflammatory disease that involves the sebaceous glands of hair follicles and is cosmetically disfiguring. It can occur in people of all ages, but has the highest incidence in adolescents. Acne can be divided into several categories according to the severity of the condition, age stage, and physical condition. The most common type of acne is common acne, which is also commonly referred to as acne. I. Facial blisters 1. Acute inflammatory type: including papules, pustules, and nodules. 2. Chronic inflammatory type: including cystic type and porous type. Various types of acne and facial blisters can exist on a person’s face at the same time and can evolve from each other. 2. Blackhead acne Includes whitehead acne, small acne, and blackhead acne. Whiteheads are unsettling type of acne (closed type) that can easily evolve into blisters. Blackhead acne is a stable type of acne (open type): not easy to change. C. Special types of acne 1. Necrotizing acne: Mostly seen in adults, the lesions are clustered papules and pustules, maroon in color, quickly necrotic, accompanied by blood crusts, repeatedly, and forming reticulated scars. 2. Premenstrual acne: It develops or intensifies before menstruation, mainly on the jaw and cheeks, with a small number of lesions. 3.Coalescent acne: The condition is more severe, with skin damage such as papules, pustules, blackheads, nodules, cysts, ulcers, sinus tracts, fistulas, and depressed scars. In addition to the face, the neck, chest and back, upper arms and thighs are all involved. 4.Infant acne: It can develop from 3 months to 2 years of age, mainly papules, pustules and blackheads, and most of them heal within 6 months, leaving point-like depressed scars.