If pimples appear near the collarbone, it is possible that folliculitis has developed in this area because the distribution of hair follicles and sebaceous glands in this area is relatively dense, and endocrine dysfunction combined with less than ideal local hygiene conditions may cause a certain inflammatory reaction. Inflammation is mostly due to excessive secretion of sebum by the sebaceous glands, and sebum that is secondary to a local condition-causing bacterial infection, such as Propionibacterium acnes infection or Staphylococcus aureus infection, may form an inflammatory response, so that acne may be seen in the appearance. It is also possible that the area is infected with a virus, for example, due to herpes simplex virus infection may form herpes simplex, which may also appear as a blister on top of the inflammation, which is also a manifestation of acne in appearance.