BIO 210 Chapter 8 & 9

skin lesion

a pathologic change in the tissues

lesions are caused by

systemic disorders (liver disease/ vascular disorders), systemic infections (herpes/ chickenpox), bacterial infections, fungal infections, allergies, exposure to toxins

physical appearance of lesion

color, elevation, texture, type of exudate

pruritus

itching

pruritus is associated with

allergic reaction, chemical irritation by insect bites, infestation by parasites

pruritus results from

release of histamine in a hypersensitivity response

diagnostic tests for skin lesions

culture/ staining, biopsy, blood tests, skin testing using patch/ scratch method

treatment for pruritus

topical agent to reduce sensation, antihistamines, glucocorticoids

treatment for infected skin lesion

antibiotics

treatment for precancerous skin lesion

surgery, laser therapy, electrodessication, cryosurgery

contact dermatitis

acute or chronic dermatitis resulting from direct skin contact with chemicals or allergens

allergic contact dermatitis

contact with poison ivy/ oak, topical antimicrobials, anesthetics, haircare products, preservatives, jewelry, rubber, essential oils, tape (causes type 2 hypersensitivity reaction)

irritant contact dermatitis

results in an inflammatory response, but no immune response

clinical manifestations of allergic contact dermatitis

small vesicles, weepy & crusted lesions

clinical manifestations of irritant contact dermatitis

area is red, scaly, itching, burning and stinging may be severe

urticaria (hives)

release of histamine causes the production of hard, erythematous lesions on the skin across the body & very itchy (caused by ingestion of substance such as shellfish, drugs, fruit) (result of type 1 hypersensitivity, often comes with anaphylaxis)

treatment of urticaria

epinephrine (check for swelling around the mouth & check airway)

atopic dermatitis

eczema

clinical manifestations of atopic dermatitis in infants

pruritic lesions, moist, red and covered in crust. located on face, neck, butt, upper/ lower limbs

clinical manifestations of atopic dermatitis in adults

lesions are dry, scaly, moist, red & in skin folds

treatment of atopic dermatitis

Topical glucocorticoids & antihistamines

Psoriasis

chronic inflammatory skin disorder resulting from abnormal T cell activation

clinical manifestations of psoriasis

lesion begins as red papule that enlarges. silver papule develops with fine bleeding. may be itching and burning (common on face, scalp, elbows, knees)

treatment for psoriasis

Glucocorticoids, tar preparations, antimetabolites, exposure to UV light

pemphigus

autoimmune disease where autoantibodies cause disruption of the epidermal cells, resulting in blister formation

scleroderma

autoimmune disorder affecting the connective tissue, increased collagen deposition

cause of scleroderma

unknown

clinical manifestations of scleroderma (CREST)

calcinosis, raynaund phenomenon, esophageal changes, sclerodactyly, telangiectasias

Calcinosis

Calcium deposits in the subcutaneous tissue that cause pain

Raynaud's phenomenon

episodes of arteriolar vasoconstriction in response to cold or stress

dysphagia

difficulty swallowing

Sclerodactyly

tightening of the skin over the fingers and toes, leads to tapering of the digits & atrophy

Talangiectasia

dilation of capillaries causing red marks on skin (when arteries become visible through the skin)

skin infections

May be caused by bacteria, viruses, fungi, other types of microbes, parasites; Caused by opportunistic microbes entered though Minor abrasions or cuts (Causative organism needs to be identified for appropriate treatment)

bacterial skin infections

acne vulgaris, furuncles, cellulitis, impetigo, acute necrotizing fasciitis

acne vulgaris

at puberty, sebaceous glands and hair follicles of the face, neck and upper trunk become plugged and infected

comedones

whiteheads/ blackheads (noninflammatory collection of sebum, sloughed epithelial cells and bacteria (clogged glans and prevent drainage)

inflammatory acne

Hair follicle swells and ruptures. Propionibacterium (normal flora) acnes breaks down sebum. inflammation. Staphylococcal organisms invade. Creation of a pustule

furuncles (boils)

caused by staphylococcus aureus (begins at hair follicle and spreads into underlying dermis - face, neck, back)

clinical manifestations of furuncles

begins as firm, red, painful module that develops into abscess (may drain purulent material) *squeezing (auto inoculation) may spread infection

carbuncle

a cluster of connected furuncles (boils)

Cellulitis (Erysipelas)

infection of the dermis & subcutaneous tissue, caused by staph & occurs in people with restricted circulation to extremities and the immunocompromised

clinical manifestations of cellulitis

area in lower trunk & legs becomes red, swollen & painful. red streaks may develop along lymph vessels

impetigo

common infection in kids caused by staph or strep. infection spreads by direct & indirect contact

clinical manifestation of impetigo

lesions on face: begin as small vesicles that enlarge/ rupture. yellow/ brown (honey) crust forms. under the crust, lesion is red & moist; releases honey colored liquid. pruritus is common, & leads to autoinoculation

treatment of impetigo

topical or systemic antibiotics

Acute Necrotizing Fasciitis

flesh eating disease, resulting in rapid destruction of tissue. mixture of aerobic and anaerobic bacteria at site of infection; causes severe inflammation & tissue necrosis

clinical manifestations of acute necrotizing fasciitis

fascia & tissues become edematous/ necrotic with occlusion of blood vessels, leading to gangrene. infected area is inflamed, painful and infection spreads rapidly. systemic toxicity can occur (fever, tachycardia, hypotension, mental confusion, possible organ failure)

treatment of acute necrotizing fasciitis

Aggressive antimicrobial therapy, fluid replacement, excision of all infected tissue; amputation

viral infections of the skin

herpes simplex & verruca (warts)

herpes simplex type 1

Most common cause of cold sores or fever blisters; occurs on/ near lips

herpes simplex type 2

genital herpes

effects of herpes simplex viruses

primary infection may be asymptomatic. virus remains latent in sensory nerve ganglia (trigeminal nerve) & recurrence is triggered by infection (cold), sun exposure, stress, ect

clinical manifestations of herpes simplex virus

burning/ tingling along trigeminal nerve on lip. vesicle ruptures and crusts. spreads by direct contact with fluid from lesion

complications of herpes simplex virus

spread of virus to eye (keratitis) & painful infection to fingers (herpetic whitlow)

verrucae (warts)

benign lesions of the skim caused by HPV. infects stratified squamous epithelium of skin & mucous membranes. transmitted by touch

clinical manifestations of verrucae (warts)

round elevation with rough/ grayish surface. often in children found on fingers (but can occur anywhere)

fungal infections of the skin

Tinea

tinea capitis

fungal infection of the scalp, common in kids. can be transmitted by cats/ dogs/ humans. circular bald patches, erythema (redness), scaling may occur. treatment is oral anti-fungal medication

tinea corporis

ringworm infection all over the body (non hairy parts). round lesions of vesicles/ papules with clear center. treatment. is topical anti-fungal medication

Tinea pedis (athlete's foot)

fungal infection of the foot/ toes. area between toes becomes inflamed, macerated (chopped up), with pruritic fissures (cracked). secondary bacterial infection may occur. treatment is topical anti- fungal medication

tinea unguium

fungal infection of the nails/ toenails. nails turn white, then brown. nail thickens & cracks. infection spreads to other nails

scabies

invasion by mite

pediculosis

infestation with lice

keratoses

Benign lesions usually associated with aging or skin damage.

seborrheic keratosis

proliferation of cutaneous basal cells that produce oval elevations (smooth or rough & dark in color). often sound on face or upper trunk

actinic keratosis

a precancerous skin growth that occurs on sun-damaged skin. lesion appears as pigmented, scaly patch. can develop into squamous cell carcinoma

squamous cell carcinoma

painless, malignant tumor of the epidermis (scab that isnt healing). found on face/ neck & in oral cavity. scaly, elevated lesion, reddish in color with irregular border & central ulceration. (tumor is slow growing. good prognosis if removed early)

basal cell carcinoma

pearly papule that develops a central ulcer known as "rodent" ulcer. no pain or pruritis. slowly invades tissue. most common & least severe skin cancer

malignant melanoma

highly metastatic form of skin cancer. develops from nevus (mole), appears as multicolored lesion with irregular border. grows quickly, changes shape/ color/ size. treatment is surgical removal, radiation & chemotherapy if needed

ABCD of melanoma

change in appearance, border, color, diameter, elevation

Kaposi's sarcoma

occurs in those with AIDS. may effect viscera as well as skin. malignant cells arise from endothelium in small blood vessels. purplish macules, nonpruritic, nonpainful. lesions develops rapidly along upper body. treatment includes surgery, radiation, chemotherapy.

fracture

break in the bone from trauma, neoplasms or increased stress on bone. (charted using \# sign)

complete fracture

bone broken, forming separate pieces

incomplete fracture

bone is only partially broken

open (compound) fracture

broken bone penetrates through the skin. can result in damage to soft tissue, blood vessels and nerves. risk of infection

closed fracture

broken bone with no open wound

simple fracture

single break, maintaining alignment and position

segmental fracture

Several large fragments separate from the main body of a fractured bone

comminuted fracture

multiple fractures and bone fragments

compression fracture

bone crushed or collapsed into small pieces (common in vertebrae)

impacted fracture

one end of the bone is forced into the adjacent bone

pathologic (spontaneous) fracture

results from bone weakness as result of disease (occurs with little stress)

stress (fatigue) fracture

occurs from repeated excessive stress

depressed fracture

skull fractured & fragments forced into brain

transverse fracture

Break occurs in a straight across the bone

oblique fracture

fracture occurs at an angle to the bone

spiral fracture

bone has been twisted apart

colles fracture

fracture of the distal radius at the wrist (fork deformity)

pott fracture

break distal end fibula (ankle), due to excessive stress on ankle

hematoma

swelling of clotted blood within the tissues.

pathophysiology of bone fractures

bleeding & hematoma formation at fracture site (serves as basis for granulation tissue to grow). inflammatory response develops & edema causes stretching/ swelling of tissue. release of bradykinin contributes to pain. systemic signs of inflammation may occur

healing of bone fracture

hematoma formation, granulation stage, procallus collar, bony callus, remodeling

hematoma formation

fibrin network is formed

granulation stage

phagocytic cells remove debris. fibroblasts lay down new collagen fibers. chondroblasts begin to form new cartilage

procalluc collar

forms a bridge between the two bone fragments

bony callus

osteoblasts from periosteum & endosteum generate new bone

remodeling phase

osteoblasts and osteoclasts remodel bone based on mechanical stresses applied to the bone (takes months)

compartment syndrome

occurs with extensive inflammation (crush injuries). fluid increases the pressure within fascia. fascia does not expand & compresses blood vessels/ nerves. causes severe pain, ischemia and necrosis

crepitus

grating sound heard as broken bones move across eachother