It is a common chronic inflammation of the hair follicle sebaceous glands. The causes include endocrine disorders, disorders of hair follicle sebum secretion, local inflammation, pore blockage, etc. 1. Endocrine disorders: endocrine disorders and increased secretion of androgens during puberty; 2. Follicular sebum secretion disorders: hair follicle sebaceous glands secrete excessively, causing acne due to hyperkeratosis of hair follicle sebaceous glands ducts; 3. Local inflammation: microorganisms in the sebaceous follicles cause local inflammation, resulting in red papules or pustules. 5, digestive system problems: such as constipation, habitual diarrhea, excessive stomach acid, ulcers, etc., resulting in the accumulation of toxins in the body, waste can not be discharged properly; 6, irregular diet: consumption of spicy and stimulating food, animal fat or sweets, or have smoking, drinking, staying up late, emotional depression and other triggers, can cause sebaceous glands secretion, resulting in the decree line acne. In short, there are more reasons for acne in the decree line area, after the acne can be appropriate exercise, avoid overwork, at the same time pay attention to diet, eat less animal fat, eat less sweets, keep the skin clean.