Derm Basic Associations

Question 1

Acne

Answer 1

inc sebum and androgen production

abnormal keratinocyte desquamation

Propionbacterium acnes

Tx - retinoids, benzoyl peroxidase, abx

Question 2

Atopic Dermatitis

Answer 2

Face in infants, antecubital fossa in kids

Inc IgE

Associated w/ asthma and allergic rhinitis

Question 3

Allergic Contact Dermatitis

Answer 3

Type IV hypersensitivity

Lesion at site of contact

Nickel, poison ivy, neomycin

Question 4

Melanocytic Nevi

Answer 4

Moles

Intradermal - papules and junctional - flat

Question 5

Pseudofolliculitis barbae

Answer 5

Razor bump in blacks

Foreign body inflammation reaction

Itchy

Question 6

Psoriasis

Answer 6

Silver scale

Esp knees and elbows

Munro microabscesses

Inc spinosum and dec granulosum

Auspitz sign (pinpoint bleeding when scale scraped off)

Question 7

Rosacea

Answer 7

Red papules and pustules but no comedones

Can be associated w/ facial flushing in response to external stimuli (heat or alcohol)

Question 8

Seborrheic Keratosis

Answer 8

Pigmented, keratin-filled cysts (horn cysts) w/ stuck on appearance

Benign and common in elderly

Leser-Trelat sign

Question 9

Verrucae

Answer 9

Warts

Cauliflower-like papules

Epidermal hyperplasia, hyperkeratosis and koilocytosis

Question 10

Urticaria

Answer 10

TRANSIENT

Hives

Wheal from mast cell degranulation

Question 11

Angiosarcoma

Answer 11

Blood vessel malignancy

Elderly, sun-exposed areas, radiation or lymphadema from mastectomy

Question 12

Bacillary Angiomatosis

Answer 12

Benign skin papule in AIDS caused by Bartonella henslae

Neutrophilic infiltrate (unlike Kaposi)

Question 13

Cherry Hemangioma v. Strawberry Hemoangion

Answer 13

Cherry - in elderly; do NOT regress

Strawberry - in infants; grow rapidly then regress by 5 to 8 yo

Question 14

Cystic Hygroma

Answer 14

Cavernous lymphangioma of the neck

Turner Syndrome

Question 15

Glomus Tumor

Answer 15

Benign, pain, red/blue

Modified smooth muscle of thermoregulatory glomus body

Often under nails

Question 16

Kaposi Sarcoma

Answer 16

Endothelial malignancy

Skin, GI, resp

HHV-8 in HIV

Lymphocytic infiltrate

Question 17

Pyogenic Granuloma

Answer 17

Polypoid, lobulated capillary hemangioma that can ulcerate and bleed

Trauma and pregnancy

Question 18

Levels of Bacterial Infection

Answer 18

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

Question 19

Pemphigus Vulgaris

Answer 19

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

Question 20

Bullous Pemphigoid

Answer 20

IgG against hemidesmosomes (BM)

Tense blisters (extra layer of skin)

Immuno shows linear pattern (straight BM)

Oral spared

Nikolsky negative

Question 21

Dermatitis Herpetiformis

Answer 21

IgA deposits at tips of dermal papillae

Papules, vesicles and bullae

Tx - dapsone and GF diet

Question 22

Erythema multiforme

Answer 22

Mycoplasma, HSV

Drugs - sulfa, beta lactams, phenytoin

Cancer and autoimmune disease

Mult type (multiform) of lesions - macules, papules, vesicles, targets

Question 23

SJS v TEN

Answer 23

Sloughing at dermal - epidermal junction

If < 10% body area then SJS
If > 30% body area then TEN (toxic epidermal necrolysis)
10-30% SJS-TEN

Question 24

Acanthosis Nigricans

Answer 24

Epidermal hyperplasia –> symmetric hyperpigmented skin thickening

Esp axilla and neck

Insulin resistance (DM, Cushing, obesity) or visceral malignancy (GI adeno)

Question 25

Actinic Keratosis

Answer 25

SCC precursor Small brown papules and plaques Sand paper like (rough)

Question 26

Erythema nodosum

Answer 26

PAINFUL Raised inflammation of subQ fat on shins Sarcoidosis, coccidio, histo, TB, leprosy, strep, IBD (chrons)

Question 27

Lichen Planus

Answer 27

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

Question 28

Pityriasis Rosea

Answer 28

Herald patch --> scaly red plaques in christmas tree distribution on trunk Self resolving in 6-8 wks

Question 29

Sunburn

Answer 29

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