types of acne pimples

skin acne anatomy sebaceous gland sebum comedones blackhead whitehead inflammation propionibacterium pustule papule nodule cyst hormonal microbiome hyperkeratinization androgens vulgaris human hair vector science health pore dermis medical infection microcomedones white blood cell attacking whiteheads blackheads formation care follicle body pimple bacteria dead cells medicine clear biology disease layers epidermis problem tissue disorder physiology diagram pimples treatment comedo pus waste bacterial