Girls with back acne are considered to be related to acne and folliculitis, etc. Acne is usually characterized by pimples, papules and pustules on the face, chest and back. 1. Acne: Acne occurs on the face, chest, and back, and is usually characterized by pimples, papules, and pustules. Its causes are related to increased androgen levels, bacterial infections, and abnormal keratinization of hair follicles. 2. Folliculitis: Folliculitis is characterized by red papules or pustules, which can occur in any area where there are hair follicles. Some female patients may have back acne, and its causes may be related to Staphylococcus aureus and streptococcus infections. There are many causes of back acne in girls, and patients are advised to seek medical examination to clarify the cause.