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Board-certified dermatology

Seborrheic Keratoses

Seborrheic keratoses are dark crusty pigmented lesions that gradually appear in adulthood, usually onsetting in mid-life. They can be thick or thin. Treatment of these lesions depends on their thickness.

Flatter seborrheic keratoses can often be improved with lasers. Dr. Rosenbach typically uses either a Long Pulsed Alexandrite laser or the Q Switched 532 laser to heat up the spot. Within 1-2 weeks the Seborrheic Keratoses will become crusty before peeling off. For the face, the crusty appearance usually lasts for a week. For other parts of the body, it can last for up to three weeks. Laser treatments are conducted monthly for around 2-4 sessions per spot.

If the spot is thick, lasers are ineffective. Dr. Rosenbach will often expose such lesions to very cold liquid nitrogen. If such thick seborrheic keratoses are located on the face, they will often become crusty, thin out and peel off in a week or so. If facial seborrheic keratoses are super thick, they could require several treatment sessions spaced monthly. For most thicker seborrheic keratoses, 2-4 monthly treatments are adequate.

Note that thicker seborrheic keratoses on the body take considerably longer to heal than on the face. It is not unusual for the crusty remnants to persist for three weeks on the body. In addition, faint reddish remnants can remain for nine or ten months. For this reason, Dr. Rosenbach often prefers to restrict liquid nitrogen treatments to the early autumn–so that patients can be back in their bathing suits the following summer without bright reddish remnants. With sunscreen, of course!

At a Glance

Dr. Alan Rosenbach

  • Board-certified and fellowship-trained dermatologist
  • Clinical associate professor at the Keck School of Medicine of USC
  • Reseacher, published author, lecturer
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