Y2S1B1 - Path - Pathoma Derm

Front 1

Type 1 hs reaction on skin, often involving face and flexor surfaces, a/w asthma and allergic rhinitis

Back 1

Atopic dermatitis or eczema

Front 2

Type IV hs reaction on skin, d/t poison ivy, nickey, chemicals (detergents), drugs (penicillin), etc.

Dx?
Tx?

Back 2

Contact dermatitis

tx: remove offending agent and topical glucocorticoids if needed

Front 3

pruritic, erythematous, oozing rash with vesicles and edema

Back 3

could easily be either atopic dermatitis or contact dermatitis! is there an irritant?

Front 4

Hormone-associated increase in sebum production and excess keratin production -> blocks follicles. Bacterial infection produces lipases that break down sebum -> proinflammatory fatty acids -> pustule or nodule

Dx?
Tx?

Back 4

Acne vulgaris (bacteria is propionibacterium acnes)

tx: Benzoyl peroxide (to knock out p. acnes) and in severe cases vitamin A derivatives (isotretinoin) to reduce keratin production

Front 5

Excessive keratinocyte proliferation! Acanthosis, parakeratosis (hyperkeratosis w/ retention of keratinocyte nuclei in stratum corneum), Munro microabscesses neuts in stratum corneum)

Dx?
Tx?

Other more-obvious associated symptoms?

Why might this be an autoimmune disease?

Back 5

Psoriasis

tx: corticosteroids, UV w/ psoralen (PUVA), or immune-modulating therapy

other signs: well-circumscribed, salmon-colored plaques w/ silvery scale, usually on extensor surfaces and scalp; possibly pitting of nails; Auspitz sign

Autoimmune: a/w HLA-C (genetic susceptibility) and lesion often arises in areas of trauma (environmental trigger)

Front 6

Wickham striae, "saw-tooth" appearance at dermal-epidermal junction, a/w chronic HCV infection, commonly involves wrists, elbows, and oral mucosa

Dx?
More description?

Back 6

Lichen Planus

pruritic, planar, polygonal, purple papules

wickham striae = reticular white lines on surface of papules or in mouth

"saw tooth" appearance - inflammation of dermal-epidermal junction

unknown etiology

Front 7

IgG antibody against desmoglein, type II hs, shallow erosions w/ dried crust on skin and oral mucosa, acantholysis, "tombstone" appearance on histology and "fish net" pattern on IF, +Nikolsky sign

Dx?
More info?

Back 7

Pemphigus Vulgaris

Autoimmune destruction of desmosomes b/w keratinocytes
suprabasal blisters, basal layer remains attached to BM (tombstone appearance)
+Nikolsky - thin bullae rupture easily, leads to shallow erosions w/ dried crust
"fish net" pattern is from IgG surrounding keratinocytes in IF

Front 8

IgG against BM collagen, tense blisters on the skin, IF shows linear IgG along the BM

Dx?
Other information?

Back 8

Bullous Pemphigoid

Autoimmune destruction of HEMIdesmosomes b/w basal cells and BM
Oral mucosa is spared! unlike pemphigus vulgaris
also because bullae do not rupture easily, is clinically milder than pemphigus vulgaris

Front 9

Grouped, pruritic vesicles and bullae, with IgA deposition at tips of dermal papillae in a patient with Celiac disease

Dx?
Tx?

Back 9

Dermatitis herpetiformis

tx: gluten-free diet

Front 10

HS reaction, targetoid rash and bullae w/ central epidermal necrosis, in a patient with HSV infection

Dx?
Other associations?

Back 10

Erythema Multiforme (EM)

a/w HSV infection but also a/w Mycoplasma infection, drugs (penicillin and sulfonamides), autoimmune disease (SLE), and malignancy

Front 11

EM with oral mucosa/lip involvement and fever. Dx?

Back 11

Stevens-Johnson Syndrome (SJS)

Front 12

Severe form of SJS characterized by diffuse sloughing of skin, resembling a large burn. Most often due to an adverse drug reaction.

Back 12

Toxic epidermal necrolysis

Front 13

Elderly patient w/ sudden onsent of raised, discolored plaques on extremities and face, coin-like, waxy, "stuck on" appearance. Histology shows keratin pseudocysts.

What is this? What is it suggestive of?

Back 13

Leser-Trelat sign (sudden onset of multiple seborrheic keratoses, which are benign squamous proliferations and when by themselves are a common tumor in the elderly)

Suggests underling carcinoma of the GI tract!

Front 14

Epidermal hyperplasia with velvet-like darkening of skin in axilla or groin

Dx?
What is this a/w?

Back 14

Acanthosis Nigricans

a/w insulin resistance (type II DM) or malignancy (especially gastric carcinoma)

Front 15

What are the risk factors for BCC, SCC, and Melanoma?

Back 15

all are UVB-related (except acral lentiginous melanoma) - prolonged exposure to sunlight, albinism, xeroderma pigmentosum

Additional risk factors for SCC are immunosuppressive therapy, arsenic exposure, and chronic inflammation (ex: scar from burn or draining sinus tract)

Additional risk factor for Melanoma is dysplastic nevus syndrome (AD disorder)

Front 16

Elevated nodule w/ central, ulcerated crater, telangiectatic vessels
Histology shows peripheral palisading

Dx?
Tx?

Other info?

Back 16

Basal Cell Carcinoma (BCC)

tx: surgical excision, metastasis is rare

"pink, pearl-like papule"

peripheral palisading means the basal cells in the basal nodule are lining up along the edge
Classically on UPPER lip

Front 17

Ulcerated, nodular mass on face, histology shows formation of "keratin pearls"

Dx?
Tx?

Classically located where?

Back 17

Squamous Cell Carcinoma (SCC)

tx: excision, metastasis is uncommon

Classically on LOWER lip

Front 18

Precursor lesion of SCC, hyperkeratotic, scaly plaque, often on face, back or neck

Dx?

Back 18

Actinic Keratosis

Front 19

Well-differentiated SCC, develops rapidly and regresses spontaneously; cup-shaped tumor filled w/ keratin debris

Dx?

Back 19

Keratoacanthoma

Front 20

Melanocytes are derived from what?

Back 20

Neural crest

Front 21

Melanocytes synthesize melanin in melanosomes from what precursor?

Back 21

Tyrosine (requires tyrosinase)

Front 22

Localized loss of skin pigmentation d/t autoimmune destruction of melanocytes. Dx?

Back 22

Vitiligo

Front 23

Congenital lack of pigmentation d/t enzyme defect, usually tyosinase, that impairs melanin production. Ocular or oculocutaneous forms

Back 23

Albinism

Front 24

Increased number of melanosomes, darken when exposed to sunlight

Back 24

Freckle (ephelis)

Front 25

Benign neoplasm of melanocytes, may have hair, flat macule or raised papule

Back 25

Nevus (mole)

there are congenital and acquired (junctional, compound or intradermal) types

Dysplasia may arise, which is a precursor to melanoma

Front 26

Most common melanoma with dominant early radial growth phase and good prognosis?

Back 26

Superficial spreading melanoma

Front 27

Melanoma with radial proliferation along the dermal-epidermal junction with good prognosis?

Back 27

Lentigo maligna melanoma

Front 28

Melanoma with early vertical growth and poor prognosis?

Back 28

Nodular melanoma

Front 29

Melanoma on palms or soles in dark-skinned individuals?

Back 29

Acral lentiginous melanoma

Front 30

Erosions with dry, crusted, honey-colored serum on face of a child. Began as erythematous macules that progressed to pustules and ruptured. Dx?

Back 30

Impetigo usually d/t s. aureus or s. pyogenes

Front 31

Red, tender, swollen rash with fever, likely after a recent surgery, trauma or insect bite. Dx?

If this progresses, it can present with "crepitus" and is a surgical emergency. Why?

Back 31

Cellulitis usually d/t s. aureus or s. pyogenes

Necrotizing fasciitis w/ necrosis of subQ tissues from anaerobic "flesh-eating" bacteria, "crepitus" is from prodn of CO2

Front 32

Sloughing of skin w/ erythematous rash and fever. What causes this? how is this different from TEN?

Back 32

Staph Scalded Skin Syndrome

s. aureus exfoliative toxins A and B cause epidermolysis of stratum granulosum, unlike TEN which occurs deeper at the dermal-epidermal junction

Front 33

Flesh-colored papules w/ rough surface usually on hands and feet, shows "koilocytic change"

Dx?

Back 33

Verruca (wart) d/t HPV infection of keratinocytes

Front 34

Firm, pink, umbilicated papules

Keratinocytes show cytoplasmic inclusions

Dx?
More info?

Back 34

Molluscum Contagiosum

d/t poxvirus

cytoplasmic inclusions = "molluscum bodies"

usually in children; also in sexually active adults and immunocompromised