Important Functions of the Skin Why Dermatology?

Home , Dermoepidermal junction

Introduction to Learning objectives • To Understand the basic structure of the skin Dermatology • To acquire the basic knowledge of the skin functions • Be able to describe skin lesions and presentations properly • Be familiar with the standard diagnostic tools in dermatology Dr. Sami N. Alsuwaidan

ASSCOCIATE PROFESSOR AND CONSULTANT IN DERMATOLOGY AND LASER SURGERY DEPARTMENT OF DERMATOLOGY KING SAUD UNIVERSITY RIYADH, SAUDIA ARABIA

Important functions of the Dermatology skin

Skin, hair, nails, and mucous - Protection against external injury membranes (mouth and genitila). - Fluid balance - Temperature buffering - Synthesis of Vit. D - Immune system - Cosmetic function

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Cornified layer

Epidermis Granular layer

Why Dermatology ? Spinous layer

Dermis Basal layer

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1 1 Skin Anatomy 1 Epidermis 2 Basement membrane (dermoepidermal junction) Epidermis 3 Dermis 4 Subcutaneous fat

Epidermis: Four layers (from outside – inside) 1. Cornified layer 2. Granular layer Dermis 3. Spinous layer 4. Basal layer

Dermis contains: 1. Collagen fibers 2. Elastic fibers 3. Ground substances 4. Blood vessels 5. Nerves.

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Skin Appendages

Hair follicle Sebaceous gland Arrector Pilli muscle Arrector pili muscle Eccrine sweat gland Hair follicle Apocrine sweat glands

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Nail Anatomy

Sebaceous gland

Eccrine gland

Apocrine gland

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1 2 Examination Primary Lesions 1. Morphology 2. Configuration Secondary lesions 3. Distribution

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Primary Lesions

Macule Papule

Plaque Nodule

Wheal

Vesicle Bulla

Pustule

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1 4 Secondary lesions

Crust Scale Ulceration Excoriation Scar Fissure Lichenification

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Color and Shape Distribution Configuration

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Dermatographism : When you stroke the Some specific signs in normal skin edema and erythema (you can write on skin!) .Seen in physical urticaria Dermatology Kobener Phenomenon : Induction of new skin lesions on previously normal appearing skin by truma e.g. in psoriasis, wart, lichen planus

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1 8 Dermatographism Kobener Phenomenon

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Additional skin examination: ~Wood’s Lamp : Produces long wave ultraviolet light(UVA). e.g. Vitiligo milky white Tinea Versicolor golden INVESTIGATIVE TOOLS Tinea Capitis (caused by microsporum) yellow green Erytherasma coral red

~Dermatoscopy : Helpful to differentiate benign from malignant pigmented lesions.

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Investigations:

*KOH and fungal culture •Scrap skin scales put over glass slide •Add KOH 10% -- warm gently •See under microscope •You may see hyphae and/ or spores

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1 9 Skin Prick Test

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Patch Test Investigations:

Skin biopsy local anasthesia, different types: •Punch •Shave •Excisional •Incisional

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Treatment: Topical Treatments Topical Various formulations: •Ointment Systemic •Cream •Gel •Solution •Lotion

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Phototherapy

Topical steroids Ultraviolet light A or B with or without psoralen PUVA (Psoralen + UVA) 7 Categories: New modalities: according to strength Narrow band UVB UVA – 1 Excimer laser(308nm)

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1 11 Dermatology subspecialties

Pediatric dermatology Photomedicine Laser Hair Disorders and Transplantation Dermatologic surgery Allergy/Contact dermatitis Dermatopathology Immunodermatology Others

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