Pathology of Skin and Integumentary System PDF

Diseases of skin and integumentary system  Outline Skin Lesions Signs and Symptoms of Skin Disease Aging and the Integumentary System Common Skin Disorders Skin Infections Skin Cancer Skin Disorders Associated With Immune Dysfunction Thermal Injuries M...

Diseases of skin and integumentary system  Outline Skin Lesions Signs and Symptoms of Skin Disease Aging and the Integumentary System Common Skin Disorders Skin Infections Skin Cancer Skin Disorders Associated With Immune Dysfunction Thermal Injuries Miscellaneous Integumentary Disorders. Common skin lesions and terminologies Urticaria, wheal Eczema, dermatitis Boil, pustule, Abscess, carbuncle Papule (pimple/acne) < 0.5cm, plaque, nodule Vesicle (up to 0.5cm), blister (0.5-1.0cm), bulla (> 1cm), Excoriation, fissures, cracks, ulcer Macule (up to 1cm) vs. Patch (> 1cm) and mole vs. freckle Skin tags, warts, callosity Erythema  Introduction Difference between skin and the integumentary system? Integumentary system is made up of your skin, nails, hair & follicle, glands, neurovascular supply Functions: Include: 1. Protection: from physical, chemical, microbial, radiation and other hazards 2. Regulation of temperature and hydration of body 3. Excretory organ 4. Sensory organ 5. Cosmetic function  Clinical features of skin diseases Symptoms Signs Signs of inflammation (redness, swelling, Burning heat) Itching Eruptions (papule, pustule, vesicles, boil, furuncle, carbuncle) Pain Swellings (abscesses etc.) Peeling Growths (inflammatory, tumors— benign and malignant) Eruption, rash Disruptions (cracks, fissures, erosions, Dry skin ulcers) Pigment problems Pigmentation (increased Abnormal sensations melanin) and depigmentation (loss of (increased, decreased or lost melanin) sensation) Roughening or thinning Secretions and discharges (serous, pus-like, bloody, mixed)  Ageing and integumentary system Ageing is physiological (may be pathological?) With ageing the structure and functions of skin are changed (less repair and more care) Following changes can be noticed: 1. It becomes thinner, loses fat, turgor, fullness, and smoothness. 2. Skin veins and bones can be seen more easily. 3. Injuries occur easily and take longer to heal. 4. Exposure to toxins and other injurious agents, especially sunlight, for a long time may lead to wrinkles, dryness, age spots, and even cancer.  Common skin conditions/disorders Pigment (melanin) disorders: Freckle, Nevus/Mole, Dysplastic Nevi, Melanoma Acute inflammatory dermatoses: Urticaria, Acute Eczematous Dermatitis, Erythema Multiforme Chronic inflammatory dermatoses: Psoriasis, Seborrheic Dermatitis, Lichen Planus Skin infections: Bacterial, viral, fungal, parasitic (warts, molluscum contagiosum, impetigo) Blistering diseases: Inflammatory: Pemphigus, bullous pemphigoid, Non inflammatory: Epidermolysis bullosa and porphyria Tumors: Benign: Seborrheic Keratoses, Acanthosis nigricans, Fibroepithelial Polyp Pre- malignant / Malignant: Actinic keratosis, squamous cell carcinoma,  Skin infections (viral) Skin infection can be caused by any of Bacteria, viruses, fungi, parasites 1.Verrucae (warts): - It is Squamo-proliferative disorders caused by human papillomaviruses. - Occur in younger ages - Infection spreads via direct contact and regress spontaneously - Various types and locations 2. Molluscum contagiosum: - It is a common, self-limited viral disease of the skin caused by a poxvirus. - Occur in younger ages - Infection spreads via direct contact and regress spontaneously - Various types and locations  Skin infections (bacterial) 1. Impetigo: - It is a common superficial bacterial infection of skin - It is caused by Staphylococcus aureus and streptococcus (group A β hemolytic) - It is highly contagious and is frequently seen in otherwise healthy children as well as occasionally in adults in poor health. - Skin involved: exposed skin, particularly that of the face and hands. 2. Common skin bacterial infections such as a.Furuncle (Boil) – pustular lesions of hair follicle and surrounding tissue b.Carbuncle – multiple furuncle together Acne? c.Abscess – larger collections of pus (with or without wall  Skin infections (fungal) 4. Tinea or ringworm (dermatophytosis): - Dermatophytes cause superficial skin infections (candida in selected cases) - They can involve any area of the skin so there are various types of clinical disease or tinea such as tinea capitis, tinea corporis, tinea unguium, tinea cruris, tinea pedis etc. Other fungi: -Tinea versicolor by Melassizea furfur -Candida albicans infection ??  Thermal injuries of skin Thermal burns are skin injuries caused by excessive heat, typically from contact with hot surfaces, hot liquids, steam, or flame. Degree of burns: depend upon extent of heat and exposure First-degree (superficial) burns. Only epidermis is affected. The burn site is red, painful, dry, and has no blisters. Mild sunburn is an example. Long-term tissue damage is rare and often consists of an increase or decrease in the skin color. Second-degree (partial thickness) burns. Involve the epidermis and part of the dermis. The burn site looks red, blistered, & may be swollen and painful. Third-degree (full thickness) burns. It destroy the epidermis and dermis completely and may involve some subcutaneous tissue. The burn site may look white or blackened. Fourth-degree burns. Along with skin, subcutaneous tissues it also involve deeper tissue, possibly involving muscle and bone. There is no feeling in the area since the nerve endings are destroyed. Area is completely destroyed, blackened and nonfunctional  Skin cancers These may be 1) Primary and 2) secondary Primary: squamous cell carcinoma, basal cell carcinoma, melanoma Secondary or metastatic: Cancers that have the highest propensity to metastasize to the skin include Melanoma from site other than skin (in 45% cases) and Cancers of the breast (30%), Nasal sinuses (20%), larynx (16%), and Oral cavity (12%) Immune mediated skin diseases (IMSD) Some of the most common IMSDs are Atopic dermatitis, Psoriasis, Vitiligo, Scleroderma, Pemphigus vulgaris, Bullous pemphigoid, Lichen planus, Erythema multiform, and Systemic lupus erythematosus (SLE).