Murdoch University CHI335 Skin PDF

CHI335 Diagnosis I The Skin Aim & Objectives Aims Assist you in understanding why the examination of the skin is important Familiarise you with the principles of observation of the skin Teach you the basics of common skin pathologies Objectives Enable you to perform general ob...

CHI335 Diagnosis I The Skin Aim & Objectives Aims Assist you in understanding why the examination of the skin is important Familiarise you with the principles of observation of the skin Teach you the basics of common skin pathologies Objectives Enable you to perform general observation & examination of the skin and learn about some associated pathologies Introduction The integumentary system consists of the skin and its accessory organs Hair follicles Arrector pili muscles (hair erector muscles) Nails Sweat and oil glands Functions of the skin Protection First line of defence against Bacteria Viruses Protects underlying structures from Ultraviolet (UV) radiation Dehydration Body temperature regulation If too hot Dermal blood vessels dilate Vessels carry more blood to the surface so heat can escape If too cold Dermal blood vessels constrict Prevents heat from escaping Regulation of Body Temperature Functions of the skin Vitamin D production Needed for calcium absorption Sensory perception Touch, pain, pressure and temperature Excretion Small amounts of waste products are lost through perspiration Skin Structure Skin Structure: Epidermis From inner most to outer most layer: Stratum basale or stratum germinativum Stratum spinosum Stratum granulosum Stratum lucidum Stratum corneum Not examinable Skin Structure: Dermis Below the epidermis Contains: Sudoriferous (sweat) glands Sebaceous (oil) glands Hair follicles and arrector pili muscles Collagen, elastic, and nerve fibres Blood vessels Binds the epidermis to the subcutaneous layer Skin Structure: Subcutaneous Layer aka Hypodermis Composed of Adipose (fat) and loose connective tissue Bigger blood vessels and nerves Functions Energy storage in adipose tissue Cushions and insulates underlying structures Techniques of Examination Inspection and palpation Note the characteristics of Colour: Erythema, pallor, cyanosis, yellowing, and hyperpigmentation Moisture: Dryness, sweating, and oiliness Mobility & turgor: lift a fold of skin and then release it Temperature: Use the back of your fingers Texture: Roughness or smoothness Lesions Anatomic location and distribution Patterns and shapes Type of lesion (macules, papules, naevi, vesicles,…) Colour Pertinent Skin terminology Lesions Macule Colour Changes Erythema (redness) Patch Pallor Papule Jaundice Plaque Cyanosis Nodule Carotenaemia Cyst Vesicle Bulla Pustule Urticaria Carotenaemia (xanthoderma): increased beta-carotene levels in the blood due to excessive consumption of Eczema carotene-rich foods, such as carrots, squash, pumpkin, and sweet potatoes – Xanthous: Yellow Skin Lesions Macules are flat, nonpalpable lesions usually 45 Early detection is crucial Most common Risk factors Sun exposure Genetic, carcinogen exposure (UV radiation, X-Ray, arsenic, soot, HPV infection) Smoking (esp. lower lip) Immunosuppression SCC Malignant Melanoma Malignant tumors of melanocytes which are found predominantly in the skin This type of skin cancer spreads rapidly and is deadly Can be seen at any age (very rare in children