Seborrheic keratoses are the raised, waxy, brown or tan growths that appear on the face, chest, back and scalp from middle age onward. Patients describe them as "stuck-on" or "barnacle-like." They are benign and extremely common, and they are also one of the growths people most want gone. Sage Dermatology removes them at our downtown Toronto clinic, usually in a single short visit.

What they are, and what they are not

A seborrheic keratosis (SK) is a build-up of normal skin cells in the top layer of skin. It is not a mole, not a wart, and not related to sun damage in the way solar lentigines ("liver spots") are. SKs are not cancerous and do not become cancerous. The reason to see a dermatologist first is that a dark, irregular SK can look like melanoma to the untrained eye, and occasionally the reverse is true. We confirm the diagnosis before treating, and if a growth is at all atypical we remove it in a way that allows it to be examined under the microscope.

Coverage and referrals

Removal of a seborrheic keratosis is almost always cosmetic. It is not covered by OHIP, and you do not need a referral to book it. The exception is a growth that needs to be removed to rule out skin cancer; that is a medical procedure and is covered with a referral from your family doctor. Irritation or catching on clothing alone does not make removal medically necessary.

How we remove them

• Cryotherapy. Liquid nitrogen freezes the growth, which crusts and falls away over one to two weeks. Quick, no anaesthetic, and well suited to thinner SKs and to treating many at once. It can leave a lighter spot, particularly on darker skin, so we choose it selectively.
• Shave removal. Under local anaesthetic, the growth is shaved level with the skin. The best option for thick or large SKs and for anything we want to examine under the microscope. Heals in one to two weeks.
• Curettage and light cautery. The growth is scraped away and the base gently sealed. Often combined with shave removal for a smooth result.

Most patients have several SKs treated in one 20-minute visit.

Aftercare and results

Treated spots scab and heal within one to three weeks. The new skin is pink at first and blends over a few months; sun protection during that time matters. A treated SK does not usually return, though new ones can appear elsewhere over the years, since the tendency is largely genetic.

Cost

Cosmetic removal is private pay and priced per visit based on the number, size and location of the growths. We confirm the fee at your consultation and provide receipts for health spending accounts.

Booking

Call 416.792.0159 or email info@sagedermatology.ca. No referral is needed for cosmetic removal. Sage Dermatology is at 591 Yonge Street, Units 202 and 203, steps from Wellesley subway station, with underground parking on Gloucester Street. Plan your visit.