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Go Back to the Top To Order, Visit the Purchasing Page for Details including the swab method (a cotton swab dipped in liquid nitrogen at -196.8℃ is brought into contact with a lesion (Fig. 6.9), and the spray method (liquid nitrogen is sprayed on a lesion at a pressure of 0.1 kg/cm2 to 0.5 kg/cm2 (Fig. 6.10). 4. Thermotherapy, Hyperthermia In thermotherapy, a lesion is warmed to 42 ℃ to 47 ℃ with warm water, a body warmer, a medical exothermic sheet or the like. This is effective in treating sporotrichosis, chromomycosis and infections of atypical mycobacteria. It may be performed as a treatment for malignant skin tumors in conjunction with chemotherapy or irradiation therapy. 6 Fig. 6.9 Cryotherapy (using stype). 5. Hyperbaric oxygen (HBO) therapy The aim of hyperbaric oxygen therapy (HBO) is to increase oxygen dissolved in the blood and to increase the partial pressure of oxygen in the tissues. It may be used for peripheral circulatory disorders such as ischemic anaerobic infections (e.g., gas gangrene), or postoperatively on skin grafts. Fig. 6.10 Cryotherapy (using spray). E. Skin surgery Skin surgery may be performed to treat various types of nevus, benign and malignant tumors, burn scars, intractable ulcers, chronic pyoderma, and tattoos. Before operation, medical indication for surgery should be carefully evaluated (particularly as to whether the lesion is malignant,). Also, the physical capability of patients to tolerate surgery should be thoroughly examined. It is important to conduct surgeries for satisfactory functional and cosmetic results. Before the use of local anesthesia, the complete medical history should be taken, and an intracutaneous test may need to be performed. Sufficient explanation about the surgery should be given to the patient in advance; moreover, it is essential to gain the patient’s written consent. Practical techniques of suturing, skin grafting, and dermabrasion are introduced briefly below. Refer to textbooks on dermatological surgery and plastic surgery for greater detail. 1. Excision and suturing A comparatively small lesion is removed and the periphery is sutured (Figs. 6.11 and 6.12). The basic method is spindleshaped excision and suturing (Fig. 6.12). If the long axis of excision is not long enough, the ends may rise in what are called dog-ears, from their shape. This is a cosmetic problem. For that reason, the long axis needs to be at least triple the width. In the event that a lesion cannot be sutured in one operation, it may be 90 6 Treatment of Skin Diseases Clinical images are available in hardcopy only. Clinical images are available in hardcopy only. 6 excised in two or more operations (serial excision). The skin may be extended using silicon prior to surgery (skin expansion), or skin graft may be performed. Excision is basically performed along the line of a wrinkle; however, excision lines are decided carefully, according to cosmetic concerns, especially when the excision is long or in the face. 2. Skin graft Clinical images are available in hardcopy only. Clinical images are available in hardcopy only. Clinical images are available in hardcopy only. When a lesion is too large for excision and suture, a skin graft is performed. Skin grafts are roughly divided into free skin grafts and pedicle grafts. Free skin grafts: Skin grafts are removed from the donor site (Fig. 6.13) and fixed (tie-over method, Fig. 6.14). The removed skin remains ischemic for approximately 4 or 5 days, until blood flow returns. Depending on the thickness of the dermal area, grafts are full-thickness (the epidermis and all of the dermal layers) or split-thickness (the epidermis and partial layers of the dermis) (Fig. 6.15). In a split-thickness graft, removed skin is processed into a mesh to raise the graft survival rate (mesh skin graft). Since skin is one of the organs that are most likely to produce immunologic rejection, the patient’s own normal skin is the only possibility for a permanent graft. Allogenic graft, dermatoheteroplasty, and biological dressing of freeze-dried pigskin are sometimes performed to temporarily cover the body. Pedicle flaps: Skin and subcutaneous tissues are not completely separated from the living body for a graft. The flaps themselves supply the blood (Fig. 6.16). Although local flaps are usually used, distant flaps may also be used. 3. Dermabrasion, Skin abrasion Clinical images are available in hardcopy only. Dermabrasion is a method of scraping away the skin surface with a high-speed grinder or dermatome. Depending on its depth, dermabrasion may produce keloids, recurrent lesions, or pigmentation; therefore, skillful performance is required. Instead of a Fig. 6.11 Excision of keratoacanthoma. Skin defect was closed by V-T flap. B A B A B Fig. 6.12 Various incisions and flaps. A 91 E. Skin surgery 6 Fig. 6.13 Split-thickness skin graft was obtained using silver knife. Clinical images are available in hardcopy only. Clinical images are available in hardcopy only. Clinical images are available in hardcopy only. Clinical images are available in hardcopy only. Fig. 6.14 Skin grafting and tie-over. With application of chemicals (e.g., salicylic acid, glycolic acid, trichloroacetic acid) to a lesion, the surface of the skin exfoliates. In many cases, cosmetic effects of chemical peeling are expected on lesions such as acne and senile lentigo. As the penetration depth can be varied so as to limit the treatment to the horny cell layer or to apply it to epidermal layers, the method most suitable for the disease or purpose should be chosen according to the chemical and the duration of activity. 5. Electrosurgery, Iontophoresis The main electrosurgeries are electrocoagulation, in which heat generated by an electric scalpel coagulates tissues (Fig. 6.17), and electrolysis, in which blood and tissue fluids are degenerated by direct-current electricity applied to the body. Iontophoresis is the process of introducing salt ions in solution through the skin into the tissues, and it may be effective in treating palmoplantar and axillary hyperhidrosis. Several iontophoresis devices are commercially available. dermis epidermis 4. Chemical peeling split-thickness skin graft (STSG) flap p subcutaneous muscle tissue high-speed grinder or dermatome, a carbon dioxide gas laser is often used to treat epidermal nevus, seborrheic keratosis, tattoos, lichen amyloidosis, porokeratosis, Darier’s disease and HaileyHailey disease. full-thickness skin graft (FTSG) Fig. 6.15 Skin thickness and various graft procedures. B A 120° 60° C D E G B E A C F D G F Fig. 6.16 Pedicle flap (Limberg flap). 92 6 Treatment of Skin Diseases 6. Laser knife Laser knives cauterize tissue using heat produced by laser. Carbon dioxide gas lasers are the principal lasers used for surgery. The advantages of surgical lasers are that there is no direct contact and that they can be used without electricity, thus making them applicable for patients with pacemakers. A surgical laser is useful for treating seborrheic keratosis and epidermal nevus; moreover, the depth is easily controlled, and injury to normal tissues is minimal. 6 Fig. 6.17 Electrocoagulation. Go Back to the Top To Order, Visit the Purchasing Page for Details