Derm Basic Associations Flashcards
Acne
inc sebum and androgen production
abnormal keratinocyte desquamation
Propionbacterium acnes
Tx - retinoids, benzoyl peroxidase, abx
Atopic Dermatitis
Face in infants, antecubital fossa in kids
Inc IgE
Associated w/ asthma and allergic rhinitis
Allergic Contact Dermatitis
Type IV hypersensitivity
Lesion at site of contact
Nickel, poison ivy, neomycin
Melanocytic Nevi
Moles
Intradermal - papules and junctional - flat
Pseudofolliculitis barbae
Razor bump in blacks
Foreign body inflammation reaction
Itchy
Psoriasis
Silver scale
Esp knees and elbows
Munro microabscesses
Inc spinosum and dec granulosum
Auspitz sign (pinpoint bleeding when scale scraped off)
Rosacea
Red papules and pustules but no comedones
Can be associated w/ facial flushing in response to external stimuli (heat or alcohol)
Seborrheic Keratosis
Pigmented, keratin-filled cysts (horn cysts) w/ stuck on appearance
Benign and common in elderly
Leser-Trelat sign
Verrucae
Warts
Cauliflower-like papules
Epidermal hyperplasia, hyperkeratosis and koilocytosis
Urticaria
TRANSIENT
Hives
Wheal from mast cell degranulation
Angiosarcoma
Blood vessel malignancy
Elderly, sun-exposed areas, radiation or lymphadema from mastectomy
Bacillary Angiomatosis
Benign skin papule in AIDS caused by Bartonella henslae
Neutrophilic infiltrate (unlike Kaposi)
Cherry Hemangioma v. Strawberry Hemoangion
Cherry - in elderly; do NOT regress
Strawberry - in infants; grow rapidly then regress by 5 to 8 yo
Cystic Hygroma
Cavernous lymphangioma of the neck
Turner Syndrome
Glomus Tumor
Benign, pain, red/blue
Modified smooth muscle of thermoregulatory glomus body
Often under nails
Kaposi Sarcoma
Endothelial malignancy
Skin, GI, resp
HHV-8 in HIV
Lymphocytic infiltrate
Pyogenic Granuloma
Polypoid, lobulated capillary hemangioma that can ulcerate and bleed
Trauma and pregnancy
Levels of Bacterial Infection
Impetigo - honey crust; very superficial
Erysipelas - upper dermis and superficial lymphatics
Cellulitis - deeper dermis and subQ (often starts w/ break in skin)
Abscess - pus (Staph)
Necrotizing Fasciitis - deeper tissue injury from anaerobes or strep pyogenes; crepitus from methane and CO2 gas; pain out of proportion to findings
Pemphigus Vulgaris
IgG against desmoglein (Type II)
Flaccid bullae from acantholysis
Immunofluorescence in reticular / net pattern (b/c between adjacent cells)
Oral involvement
Nikolsky sign - separation of epidermis on stroking skin
Bullous Pemphigoid
IgG against hemidesmosomes (BM)
Tense blisters (extra layer of skin)
Immuno shows linear pattern (straight BM)
Oral spared
Nikolsky negative
Dermatitis Herpetiformis
IgA deposits at tips of dermal papillae
Papules, vesicles and bullae
Tx - dapsone and GF diet
Erythema multiforme
Mycoplasma, HSV
Drugs - sulfa, beta lactams, phenytoin
Cancer and autoimmune disease
Mult type (multiform) of lesions - macules, papules, vesicles, targets
SJS v TEN
Sloughing at dermal - epidermal junction
If < 10% body area then SJS
If > 30% body area then TEN (toxic epidermal necrolysis)
10-30% SJS-TEN
Acanthosis Nigricans
Epidermal hyperplasia –> symmetric hyperpigmented skin thickening
Esp axilla and neck
Insulin resistance (DM, Cushing, obesity) or visceral malignancy (GI adeno)
Actinic Keratosis
SCC precursor
Small brown papules and plaques
Sand paper like (rough)
Erythema nodosum
PAINFUL
Raised inflammation of subQ fat on shins
Sarcoidosis, coccidio, histo, TB, leprosy, strep, IBD (chrons)
Lichen Planus
Ps
Pruritic, Purple, Polygonal, Planar, Papules
If mucosal involvement … Wickham striae (white lines) and hypergranulosis
Sawtooth infiltrate of dermis - epidermal junction by lymphocytes
Hep C
Pityriasis Rosea
Herald patch –> scaly red plaques in christmas tree distribution on trunk
Self resolving in 6-8 wks
Sunburn
Acute cutaneous inflammatory reaction due to UV radiation
DNA mutation –> apoptosis of keratinocytes
UVA - tAnning, photoAging
UVB - sunBurn
Both inc risk all 3 skin cancer types
