Eating chili peppers is more likely to cause acne than drinking milk.
The underlying cause of acne, due to excessive sebum production, is the basic pathological mechanism of acne, accompanied by abnormal keratinization of the cells surrounding the hair follicles. Acne vulgaris is accompanied by an overproliferation of Propionibacterium acnes, on top of which inflammation develops.
The most important triggers of acne are high sugar diet, dairy products, etc. which can trigger acne or make it worse. So if you want to control acne, eat less sweets and whole milk.
Cayenne pepper itself has no direct aggravating effect on acne, but chili pepper is usually accompanied by high salt and high oil cooking, so from this point of view, the usual diet should be less oil, less salt and light. Acne sufferers are cautioned to drink little or no milk, and to seek medical attention promptly offline if necessary.