Introduction To Dermatology PDF

INTRODUCTION TO DERMATOLOGY Introduction on skin or Integumentary system Integumentary system is your body’s outer layer. It’s made up of skin, nails, hair and the glands and nerves on skin. Your integumentary system acts as a physical barrier protecting the body from bacteria, infection, injury...

INTRODUCTION TO DERMATOLOGY Introduction on skin or Integumentary system Integumentary system is your body’s outer layer. It’s made up of skin, nails, hair and the glands and nerves on skin. Your integumentary system acts as a physical barrier protecting the body from bacteria, infection, injury and sunlight. It also helps regulate your body temperature and allows you to feel skin sensations like hot and cold.  Layers of skin Epidermis: The top layer of skin. Contains stratified squamous epithelial tissue.  This is the part of your skin that you can see and touch. It’s made up of three types of cells: melanocytes, keratinocytes and Langerhans. It gives your skin its color and provides a waterproof barrier. Dermis: The middle layer of your skin. This layer is the thickest. It contains sweat and oil glands and hair follicles. Hypodermis: The bottom layer of your skin. It’s the fatty layer of your skin that helps insulate your body. Cells of Epidermis Melanocytes Produce melanin pigment ( skin color) Langerhans cells Responsible for immunity Merkel cell Unknown function Dermis Papillary layer Reticular layer Consist of connective tissue; blood vessels, nerves, glands and hair follicles, collagen and elastic fibers help with strength and elasticity. Cells of dermis Hair follicles Sebaceous and sweat gland Regulation of body temperature. Meissner corpuscules Responsible for sensation & touch. Subcutaneous layer Subcutis or hypodermis Consist of an insulating layer of fat and blood vessels, is an important line of defense Assessment of the skin: Cutaneous signs Primary lesion Secondary lesion visible to the naked When the primary eye and refer to the lesions progress or lesions appearing for undergo modification the first time by recovery, injury. Primary lesion Macule Circumscribed changes in the color of skin It may be oval or circular without elevation or depression It may be hyper- pigmented : Hemangioma It may be hypo- pigmented : Vitiligo Vitiligo Hemangioma The melanocyte destroyed A non-cancerous reddish tumor formed of excess blood vessels. The way to remember !! Cutaneous sign that may be oval or circular without elevation or depression: A. Macule B. Nodule C. Bulla D. Vesicle  Papule Solid elevation of the skin with diameters less than 5 mm It may be oval or circular without elevation or depression it affect epidermis and upper dermis It may flat: lichen planus It may dome shaped : xanthoma Xanthoma Lichen planus Inflammatory Tumor due to high level of blood lipids  The way to remember !! Cutaneous sign that is considered a solid elevation of the skin with diameters less than 5 mm: A.Macule B. Papule C. Bulla D. Vesicle  Nodule Similar to papules, but their diameters are normally larger than 5 mm Nodule is an intermediate form between papules and small tumors it may affect any layer of skin  The way to remember !! Cutaneous sign that is considered a solid elevation of the skin with diameters more than 5 mm: A.Macule B. Nodule C. Bulla D. Vesicle Bulla Bullae have diameters more than 1 cm Ex : Pemphigus Pemphigus vulgaris Autoimmune condition where there is painful blistering on the skin and mucous membranes The way to remember !! Autoimmune condition where there is painful blistering on the skin and mucous membranes A. Pemphigus B. Cellulitis C. Herpes zoster D. Dermatitis Vesicle Vesicle have diameters less than 1 cm, Ex : Herpes zoster Herpes zoster A viral infection caused by varicella-zoster characterized by painful rash with blisters The way to remember !! The diameter of the vesicle is: A. Less than 1 cm B. Less than 5 cm C. More than 1 cm D. More than 5 cm  Pustule A chronic skin disease which results in scaly, often itchy areas in patches A chronic skin disease which results in scaly, often itchy areas in patches The way to remember !! The pus is observed with the eye in : A. Macule B. Nodule C. Bulla D. Pustule Cyst Cysts refer to epidermal nodules containing fluid or semisolid materials The way to remember !! The epidermal nodules containing fluid or semisolid material : A.Macule B. Nodule C. Bulla D. Cyst  Plaque Plaques are elevated skin with 2 cm in diameter. They can be considered as grown papules, and they occur in mycosis fungoides Mycosis fungoides Diseases in which lymphocytes (a type of white blood cell) become malignant (cancerous) and affect the skin The way to remember !! The elevated skin with 2 cm in diameter. They can be considered as grown : A. Macule B. Nodule C. Bulla D. Plaque Secondary lesion Scale Scales are aggregates of keratin debris in the stratum corneum. In psoriasis, scales look white or silver The way to remember !! Are aggregates of keratin debris in the stratum corneum : A. Macule B. Nodule C. Bulla D. Scale Excoriation Caused by mechanical traumas or repetitive scratching to ease pruritus. Scabies Excoriations are often developed in scabies An intensely itchy rash caused by a mite known as Sarcoptes scabiei. The way to remember !! Caused by mechanical traumas or repetitive scratching to ease pruritus : A. Excoriation B. Nodule C. Bulla D. Scale Ulcer skin loss extending through the epidermis and part of the dermis They are generally caused by impaired or restricted supply of blood or nutrition due to the peripheral vascular diseases The way to remember !! Skin loss extending through the epidermis and part of the dermis. : A. Excoriation B. Nodule C. Bulla D. Ulcer Fissure Fissures are linear cleavages of the skin which sometimes extend into the dermis They are frequently developed around the flexural side of finger joints, finger tips, palms of the hands, lateral sides of the fingers and toes, oral angles, nostrils, auricles. The way to remember !! They are frequently developed around the flexural side of finger joints : A. Excoriation B. Nodule C. Fissure D. Ulcer Scar Scars, as a part of the healing processes, replace the damaged skin tissues. Their shape and size are determined by that of the defect. Thin atrophic scars are observed in syphilis A highly contagious sexually transmitted bacterial infection.  Disease according to skin color Increase melanin Brown concentration Liver disease White Absence of melanin con. Albinisms Vitiligo Red Polycythemia Increase Erythrocyte Yellow Increase Bile Hypothyroidism Decrease oxidized Cardiovascular & Blue hemoglobin pulmonary  Summary Primary lesion Flat ( change in color ) Raised lesion Macule Less than 1 cm Papule Less than 0.5 Plaque More than Pustule Contain pus cm 0.5 cm Summary Primary lesion Large fluid sacs Small fluid sacs Nodule Deep layer of the Cyst Superficial layer of Vesicle Small in size , Bulla Large in size , skin the skin large in number small in number  Summary Secondary lesion Depressed lesion Raised lesions Excoriation Fissure Cut shape Ulcer Circular Scale Superficial Scar Deep Longitudinal