Electrocautery vs Q-switch for Seborrheic Keratosis

Inclusion Criteria: 1. Subjects are Caucasian or Asian. 2. Subjects who are between 18-65 year olds. 3. Subjects have flat or macular seborrheic keratosis on dorsum of the hands and wrists, extensor surfaces of the forearms. The diagnosis of flat seborrheic keratosis is confirmed by two clinical dermatologists using routine clinical examination and dermoscopy. 4. Subjects have Fitzpatrick skin type I-III. 5. Subjects are in good health. 6. Subjects have the willingness and the ability to understand and provide informed consent and communicate with the investigator. Exclusion Criteria: 1. History of keloids or hypertrophic scars. 2. Pregnant or lactating or intends to become pregnant in the next 3 months. 3. Active skin disease or skin infection in the treatment area. 4. Previous history of lidocaine allergy. 5. History of methemoglobinemia 6. Unable to understand the protocol or to give informed consent. 7. Any other condition that would, in the professional opinion of the investigator, potentially affect response or participation in the clinical study or would pose as an unacceptable risk to subject.