All occur in hair follicles, but each has its own characteristics.

Folliculitis refers to the inflammation of hair follicles, which can be papules or pustules, or it can be papules followed by pustules. It has many causes, and bacterial infection is just one of them. And pathogens are not limited to staphylococcus and streptococcus. The papules or pustules of folliculitis can be more or less, large or small, deep or shallow, but they must grow in hair follicles. Generally, the rash of folliculitis is relatively small, often from mung bean to matchhead. Pustules are also shallow, so they feel painless or only slightly painful. More common in scalp and facial hairy areas, chest, upper back and limb extension. Furuncle, also known as furuncle and furuncle swelling, is acute suppurative deep folliculitis and folliculitis caused by staphylococci invading hair follicles. It started as a red nodule and soon festered into a purulent nodule or pustule. Its position is deep, so the pain and tenderness are more intense. The common site is folliculitis, but it can be widely distributed. A typical boil has a pus head in the center, which can discharge yellow-green pus thrombus (folliculitis does not have this situation) and pus blood, leaving scars after healing.