| Term | Definition |
| acne vulgaris | A skin disease characterized by blackheads (the result of blocked hair follicles becoming infected with bacteria), whiteheads, and pus-filled lesions |
| folliculitis | Inflammation of a hair follicle |
| hidradenitis | Inflammation of a sweat gland caused by occlusion (closing off) of the pores with subsequent bacterial infection of the gland |
| onychopathy | Any disease of the nails |
| seborrhea | Excessive production of sebum |
| seborrheic dermatitis | An inflammatory condition of the skin that begins with the scalp but may involve other areas, particularly the eyebrows; commonly called dandruff |
| trichosis | Any abnormal condition of hair growth, including baldness or excessive hair growth in an unusual place |