HLTH 2501: skin disorders Flashcards
skin lesion causes
systemic disorders such as liver disease, systemic infections like chickenpox, allergies to food or drugs, or exposure to toxics
what are lesions classified on?
their physical appearance (colour, elevation, texture), type of exudate, and the presence of pain or itching
types of lesions
macule, papule, nodule, pustule, vesicle, plaque, crust, lichenification, keloid, fissure, ulcer, erosion, or comedone
macule
small, flat, circumscribed lesion of a different colour than the normal skin
papule
small, firm, elevated lesion
nodule
palpable, elevated lesion that varies in size
vesicle
elevated, thin-walled lesion containing clear fluid (blister)
pustule
elevated, erythematous lesion, usually containing purulent exudate
crust
dry, rough surface or dried exudate or blood
lichenification
thick, dry, rough surface (leathlike)
keloid
raised, irregular and increasing mass of collagen resulting from excessive scar tissue formation
fissure
small, deep, liner crack or tear in skin
ulcer
cavity with loss of tissue from the epidermis and dermis, often weeping or bleeding
erosion
shallow, moist cavity in epidermis
comedone
mass of sebum, keratin, and debris blocking the opening of a hair follicle; blackheads and whiteheads
what is pruritus associated with?
allergic reactions, chemical irritation, insect bites, or infections by parasites
example of a parasite that causes itching
scabies mites
why does pruritus occur?
it is not totally understood but histamine release causes this as well as mild stimulation of pain receptors by irritants
why may secondary infections occur with itching?
because microbes from under the nails may enter into the skin via stratching
testing for bacterial infections
includes culture and staining of specimens for identification
testing for fungal or parasitic infections
includes microscopic examination, sample culturing, direct observation, and other procedures such as UV light or Wood’s lamb
testing for malignant changes in tissue
may be done by biopsy
testing for allergy or abnormal immune responses
can be done via blood tests or scratch tests
testing for drug reactions
uses specific antibody-antigen testing
treatment for pruritus
antihistamines or glucocorticoids, avoiding allergies, and soaks or compresses
how may precancerous lesions by removed?
surgery, laser therapy, electrodessication, or cryosurgery
electrodessication
removing precancerous lesions via heat
cryosurgery
removing precancerous lesions via freezing by liquid nitrogen
how do topical agents reduce itching?
some hae a local anesthetic to reduce itching and burning sensations
what do burns cause?
an acute inflammatory reaction
contact dermatitis
may be caused by exposure to an allergen or by direct chemical or mechanical irritation of the skin
allergy dermatitis
may result from exposure to any of multiple substances, including metals, cosmetics, soaps, chemicals, and plants
where does poison ivy cause lesions?
on the ankles and hands
how does an allergy develop?
sensitization occurs on the first exposure and then on subsequent exposures, manifestations such as a pruritic rash develop
signs of allergic dermatitis
pruritic area, erythematous (reddened) area, edematous (swollen) area, and area often covered with small vesicles
direct chemical irritation signs
edematous (swollen) area, erythematous (reddened) area, and pruritic or painful area
treatment for allergic and contact dermatitis
removal or the irritant and reduction of the inflammation with a topical glucocorticoid
hives other name
urticaria
what does urticaria usually result from?
a type 1 hypersensitivity reaction, commonly caused by shellfish or certain fruits or drugs
signs of urticaria
histamine release causes eruption of hard, raised, erythematous lesions on the skin, highly pruritic lesions, and if in the airway, can obstruct breathing
treatment for urticaria
over-the-counter antihistamines usually work; if inflammation of the airway occurs, corticosteroids can be used, and in severe cases omalizumab can be used for those > 12
another name for eczema
atopic dermatitis
atopic meaning
refers to an inherited tendency towards allergic reactions
family history of atopic dermatitis
common in those with allergic rhinitis or hay fever and asthma
what is atopic dermatitis
is chronic inflammation that results from a response to allergens
what are serum levels for those with atopic dermatitis?
high eosinophil count and increased IgE levles
potential complications associated with atopic dermatitis
secondary infections due to itching and disseminated viral infections such as herpes
what may aggravate atopic dermatitis?
soaps, certain fabrics, changes in temperature, and humidity
signs of atopic dermatitis in infants
pructic lesions that are red, moist, vesicular and covered with crusts, often on the face, neck, extensor surfaces of arms and legs, and buttocks
atopic dermatitis signs in adults
dry and scaling skin, thick and leathery patches called lichenification, skin folds are moist and red, and pruritus is common
treatment of atopic dermatitis
eliminating aggravating agents, topical glucocorticoids, antihistamines, adequately moisturizing the skin, and trying a hypoallergenic diet
psoriasis
is a chronic inflammatory disorder that affects 1-3% of the population is is genetic
psoriatic arthritis
usually begins with psoriasis and progresses to the joints
when does psoriasis usually begin?
in the teen years
what is psoriasis a result of?
abnormal activation of T cells and an associated increase in cytokines in affected tissue; this then leads to a proliferation of keratinocytes that cause the symptons
what does psoriasis appear as?
lesions that begin as small, red, paule; these then enlarge and a sliverly plaque forms, while the base remains erythematous because of inflammation and vasodilation
where are psoriasis lesions common?
the face, scalp, elbows, and knees; nails are also affected, being thickened, pitted, or ridged
signs of psoriasis
red patches of skin covered with silvery scales, small, scaling spots, dry, cracked skin that may bleed, itchicing, burning, soreness, thickened, pitted or ridged nails, and swollen, painful or stiff joints
what is the goal of psoriasis treatment?
to stop skin cells from growing too quickly and removing scales
treatment for psoriasis
topical therapy, light therapy, and oral medications or injections
topical therapy for psoriasis
corticosteroids, vitamin D analogs (ex. calcitriol), retinoids, calcineurin inhibitors, salicylic acid shampoo, and coal tar
what are calcineurin inhibitors?
they reduce inflammation and plaque buildup
coal tar
reduces scaling, itching, and inflammation
light therapy for psoriasis
sunlight, UV B broadband and narrowband, excimer laser, and psoralen plus UV A
oral medications or injections for psoriasis
steroids, retinoids, methotrexate, cyclosporine, and biologics
pemphigus
is an autoimmune disorder that occurs when autoantibodies disrupt the cohesion between the epidermal cells, causing blisters to form
two forms of pemphigus
pemphigus vulgaris and pemphigus foliaceus
what form of pemphigus is more common?
pemphigus vulgaris
what occurs in pemphigus vulgaris?
the epidermis separates above the basal layer, forming blisters that become large, rupture, and leave large areas of skin covered with crust
signs of pemphigus vulgaris
blisters in the mouth that spread to the skin, blisters are painful but not itchy, and breathing difficulties can occur due to swollen mouth and throat
pemphigus foliaceus
similar to vulgaris but there are no mouth blisters nor are the blisters painful
treatment for pemphigus
systemic glucocorticoids such as prednisone and other immunosuppressants
scleroderma
may occur as a skin disorder or may affect the viscera
cause of scleroderma
not known but increased collagen deposits are observed in all cases
how does scleroderma develop?
collagen deposition in the arterioles and capillaries reduces blood flow to the skin or internal organs, causing inflammation and fibrosis to develop in the skin
signs of scleroderma
hard, shiny, tight immoveable areas of the skin, short and narrow fingertips, and facial expression is lost as the skin tightens
raynaud phenomenon
may be present in scleroderma, causing atrophy and ulcers in the fingers
what may occur along with scleroderma?
microcirculation of other organs, causing renal failure, intestinal obstruction, or respiratory failure
treatment for scleroderma
varies but can be anti inflammatory drugs, immunosuppressive therapies, or antifibrotic agents
dupuytren’s contracture
is a slow developing hand deformity that involves the development of knots of tissue under the skin on the palms of the hands; this eventually pulls the fingers into a bent position
how does dupuytren’s contracture develop?
begins as thickening of the skin of the palm that progresses to a lumb that then extends into cords of tissues that pull on the fingers
treatment for dupuytren’s contracture
stretching, steroid and/or enzyme injections, radiation treatment, and in some cases surgery
