Surgery and Other Physical Treatment Modalities

	Principles of Skin Therapy

		Surgery and Other Physical Treatment Modalities surgery curettage electrotherapy cryotherapy ultraviolet therapy intralesional therapy laser therapy dermabrasion, chemical peel
		SURGERY Skin is accessible to surgical procedures for diagnostic or therapeutic intent. One must, however, be conscious of potential side effects such as scarring, and avoid unnecessary surgery. You will learn cutaneous anatomy and simple cutaneous surgical procedures during your dermatosurgery elective. A special form of cutaneous surgery, called micrographic surgery, is worth mentioning. this technique is used for excising complicated skin tumors using transverse skin sections, the skin tumor is carefully mapped out and completely excised labour-intensive and indicated for difficult tumors such as ones that recur after radiation therapy, ones that have ill-defined borders, or ones that are close to vital structure OTHER PHYSICAL TREATMENT MODALITIES
	Curettage	1. Curettage Scraping off a skin lesion with a curette Suitable for epidermal lesions that separate easily from the surrounding tissue, e.g. seborrheic keratosis, basal cell carcinoma, some warts
	Electrotherapy Electrotherapy	2. Electrotherapy Using heat generated by an electric current to destroy (burn off) a skin lesion Suitable for burning off small epidermal lesions, e.g. skin tags around the neck Combined with curettage for the treatment of basal cell carcinoma Used in electrocoagulation of facial telangiectasia (now replaced by laser) Its use in the treatment of warts is to be discouraged because of the risk of scarring
	Cryotherapy of Wart Cryotherapy Cryotherapy Post-Cryotherapy Cryotherapy of Seborrheic keratosis	3. Cryotherapy With mild freezing, the epidermis separates from the dermis. This technique can be used to remove epidermal lesions such as actinic keratosis, seborrheic keratosis, warts. With deeper freezing, tissue can be destroyed. This can be used to treat skin tumors, but not on a routine basis. The colder the cryogen, the deeper the destruction. A fast freeze and slow thaw is more damaging than a slow freeze and fast thaw. Repeating the freeze-thaw cycle also leads to increased cell lethality. Cryogens: Hydrocarbon 12 (Freon 12): - 60^o C Nitrous oxide cryoprobe: - 88^o C Liquid nitrogen: - 196^o C Only liquid nitrogen is suitable for the treatment of skin tumors. A spray apparatus should be used; a cotton swab is inadequate. Complications of cryotherapy: hyper- or hypopigmentation of the skin, scarring, nerve injury
	Ultraviolet therapy	4. Ultraviolet therapy Two major types: UVB and PUVA (psoralen + UVA) Psoralen when activated by UVA intercalates with and cross-links DNA Psoralen can be taken by mouth or applied to the skin topically UVB is helpful in psoriasis and some eczemas (mechanism unknown) PUVA is used in the treatment of psoriasis, vitiligo, some eczemas, and cutaneous T cell lymphoma. It may have local and systemic immunomodulatory effects. PUVA may also be used to treat cutaneous photosensitive disorders by desensitizing the skin. Complications of phototherapy include acute side effects of skin burning and chronic side effects of photoaging and skin cancer.
	Intralesional Therapy	5. Intralesional therapy Medication is directly injected into a skin lesion Used when percutaneous penetration of the drug to the target site is not adequate e.g. intralesional corticosteroid treatment of keloids or acne cysts e.g. intralesional chemotherapy for skin cancers
	Laser Light Characteristics Optical Absorption Selective photothermolysis Post-Laser Treatment	6. Laser therapy Laser stands for Light Amplication by the Stimulated Emission of Radiation Laser is coherent, monochromatic (single wavelength) and collimated Safety of cutaneous laser treatment is enhanced by utilizing the principle of selective photothermolysis. Selective heating (destruction) of target cell/tissue is achieved by preferential light absorption and heat production in target. Also, heat localization is controlled by precise laser exposure time. Various organelles/cells or tissues in the skin can be selectively targeted, e.g., pigment cells, blood vessels, hair follicles
		7. Dermabrasion, chemical peel Dermabrasion is a technique of skin abrasion performed with a motor-driven diamond fraise or steel brush. It is used to remove scars. The depth of the abrasion is controlled by the operator. Dermabrasion done too deeply can result in scarring. It can also cause hyper- or hypopigmentation. Chemical peel is the use of chemicals to ‘peel off’ the outer layers of the skin. The depth of the ‘peel’ depends on the agent used (e.g. alpha-hydroxy acids - superficial, phenol and trichloroacetic acid gives deeper peels).