Summer pimples, also known as acne, may be considered to be related to the exuberant secretion of sebaceous glands, inadequate skin cleansing, over-keratinization of follicular sebaceous gland openings, and infection by Acinetobacter propionicus. 1. Excessive secretion of sebaceous glands: In summer, when the weather is hot, there is excessive loss of moisture and a relative increase in sebum secretion, which can cause more sebum secretion to adhere to the surface of the skin, thus leading to acne. 2. Skin cleaning is not in place: summer is easy to sweat, skin secretion secretion is relatively increased, if the skin cleaning is not in place, sweat, sebum and dust easily lead to pore clogging, causing bacterial infection, which leads to acne. 3. Excessive keratinization of follicular sebaceous gland openings: due to genetic and endocrine reasons, the keratinocytes at the openings of the follicular sebaceous glands can be over-keratinized, making the openings of the sebaceous glands smaller, or even blocked. 4. Acinetobacter propionicus infection: When sebum is overproduced and the sebaceous gland openings are clogged, Acinetobacter propionicus infection around the hair follicles can be caused, resulting in acne. There are many reasons for acne in summer, and it is recommended to take good care of the skin in summer, keep the skin clean and dry, and at the same time, it is recommended to go to the dermatology department of a professional hospital in time, and do not use medication privately, so as not to cause serious adverse reactions.