The appearance of pimples on the skin after changing cosmetics is considered to be related to cosmetics and it is advisable to avoid using them. It is possible that cosmetics are too greasy, thus blocking the sebaceous gland ducts of the hair follicles, making acne appear. It is also possible that cosmetics contain glucocorticoids, which can lead to the appearance of acne. If the acne is caused by glucocorticoids, the rash is usually uniform in size, red or skin color, sometimes accompanied by pus, and there are obvious red spots around the rash. It is recommended that if the above situation occurs, you need to stop using cosmetics in time. It is best to take the cosmetics to the regular medical institutions for patch test, to clarify whether it is an allergic reaction to certain ingredients in the cosmetics and acne, if it is due to allergy acne, usually accompanied by itching.