Skin Surface Analysis

Skin surface analysis is often tailored to the goals of restorative surgery or nonsur-gical treatments. Patients undergoing scar revisions require analyses to include the resting skin tension lines. In the patient undergoing nasal reconstructive surgery after Mohs' resection, an analysis of the topographical units of the face is important. If cutaneous resurfacing is planned, an analysis of skin type and reaction to solar damage are also needed. Koebner's phenomenon is also an important consideration. This phenomenon describes the tendency for some skin diseases such as psoriasis, lichen planus, discoid lupus erythematosus, and herpes simplex to localize to areas of recent surgery or scars.

Histological Findings I

Epidermis %

The epidermis is approximately 100 mm thick and is divided into four layers. The >3

basal cell layer or stratum germinativum is a single cell layer giving rise to subsequent layers and interspersed with melanocytes in varying numbers, depending on the part of the body. The prickle cell layer or stratum spinosum is three or four cell layers thick, containing intracellular preformed keratin (named prickle cells

Microanatomy The Epidermis
Figure 12 Microanatomy of the epidermis.

based on the desmosomes appearing as small spines coming from the cells). The granular cell layer or stratum granulosum is one to four cell layers thick, containing intracellular preformed keratin granules. A cornified layer or stratum corneum, is several layers thick and is formed by coalescence of the granules in the third layer

The epidermis contains four major cell types including keratinocytes (80%), melanocytes, Langerhans' cells, and Merkel's cells. Merkel's cells are found in the basal cell layer of the epidermis and are part of the amine precursor uptake decar-boxylation (APUD) system. Their function is unknown; however, Merkel cell tumors may arise from these cells. The melanocytes are also found within the basal cell layer and produce melanin pigment. In blacks, these melanocytes are very active, in areas of vitiligo they are absent, and in those with albinism they are present but lack the enzyme tyrosinase (for tyrosine-to-melanin conversion).

Basement membrane s

The basement membrane is a well-defined multilayered structure between the epider- g mis and dermis that serves two functions: as a barrier to cells and chemicals, and to support and attach the epidermis to the dermis. The membrane consists of several layers visualized on electron microscopy including (18) the following: g

Attachment plaque with tonafilaments and hemidesmosomes

The lamina lucida under the attachment plaque with anchoring filaments o

The lamina densa under the lamina lucida with anchoring dermal microfibril ยง

bundles (type VII collagen)

How To Reduce Acne Scarring

How To Reduce Acne Scarring

Acne is a name that is famous in its own right, but for all of the wrong reasons. Most teenagers know, and dread, the very word, as it so prevalently wrecks havoc on their faces throughout their adolescent years.

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