Keratosis is a word that covers two unrelated conditions, and people searching it usually have one and are reading about the other. Both involve keratin, the protein of the skin’s surface, building up where it should not. That is where the similarity ends.
Seborrheic keratosis: the stuck-on growth
Seborrheic keratoses are the waxy, raised, brown or tan growths that appear from the 40s onward on the face, chest, back, and scalp, sometimes one at a time and sometimes by the dozen. They look stuck onto the skin rather than grown from it, can be crumbly or rough, and often alarm people because they appear quickly and can be dark. They are benign. They do not become cancer, they do not spread, and they need no treatment unless they itch, catch on clothing, or bother you.
Removal is a single visit. A provider freezes the growth with liquid nitrogen, after which it blisters slightly and falls away over a week or two, or shaves it flat under a drop of local anesthetic, which leaves a small pink patch that fades over weeks. Several can be removed at once. On deeper skin tones, shaving is often preferred because freezing can lighten the surrounding skin.
The one rule: because seborrheic keratoses can resemble melanoma, a growth that is very dark, irregular in shape or color, changing fast, or bleeding gets a dermatologist’s look before cosmetic removal. A clinic that checks first is doing it right.
Keratosis pilaris: the rough bumps
Keratosis pilaris, often called chicken skin, is the field of small rough bumps on the backs of the upper arms, the thighs, the buttocks, and sometimes the cheeks. It happens when keratin plugs the hair follicles, and it is genetic, extremely common, harmless, and stubborn. It often improves with age and worsens in dry, cold months.
There is no cure and there is good management. A series of exfoliating chemical peels with lactic or glycolic acid smooths the bumps considerably over four to six sessions. Laser can reduce the redness that comes with some forms. Between and after treatments, a daily lotion with lactic acid, urea, or salicylic acid, applied consistently, keeps the follicles clear; stop it and the bumps return within weeks. Scrubbing does not help and often inflames it.
How to choose a provider
For a seborrheic keratosis, ask whether they examine the growth before removing it and which method they use for your skin tone. For keratosis pilaris, ask what series they recommend, what home routine goes with it, and what improvement is realistic; a provider who promises smooth arms after one visit has not treated much of it.
Browse the clinics below. If you are not sure which keratosis you have, a photo in daylight settles it quickly at the consultation.