4th Exam: Skin Diseases

Question 1

Macule:

Answer 1

Flat, often circumscribed color difference, often red, brown, ex: measles

Question 2

Papule:

Answer 2

Elevated, dome shaped, diameter < .5cm, ex: Lichen planus

Question 3

Plaque:

Answer 3

Elevated lesions, flat top, larger than papules, diameter > .5cm, ex: eczema

Question 4

Vesicle:

Answer 4

Blisters, water-filled, diameter <0.5 cm, ex: Herpes simplex

Question 5

Bulla:

Answer 5

Larger blister than vesicles, diameter > 0.5cm, ex: bullous pemphigoid

Question 6

Pustule:

Answer 6

Raised, yellow or white, polys in vesicles, ex: Herpes simplex

Question 7

Crusting:

Answer 7

Vesicles or pustules break, contents dry and harden, ex: Herpes simplex

Question 8

SCale:

Answer 8

White lesions, thickened Stratum Corneum, hyperkeratosis, ex: psoriasis, ichthyosis

Question 9

Hyperkeratosis:

Answer 9

Thickened Stratus Corneus of keratin layer (causes SCales), ex: psoriasis, ichthyosis, actinic keratosis

Question 10

Parakeratosis:

Answer 10

Nucleated cells in stratum corneum (normally no nuclei, keratin, dead cells), rapid proliferation of epi, ex: psoriasis

Question 11

Papillomatosis:

Answer 11

Epidermis forms papillae, hyperplastic, ex: wart

Question 12

Acanthosis:

Answer 12

Thickened epidermis, uniform or irregular, ex: lichen planus

Question 13

Spongiosis:

Answer 13

Intercellular edema, vacuoles bw epi cells, cause: acute injury, ex: eczema

Question 14

Acantholysis

Answer 14

Loss of cohesion bw keratinocytes, spaces bw cells, ex: Pemphigus

Question 15

Eczema:

Answer 15

Nonspecific clinical term, prototype for many rashes, acute/ subacute/ chronic, red, vesicular, oozing, crusting, later: raised scaling plaques, pruritis (itchy)

Question 16

Causes of Eczematous Rashes:

Answer 16

Contact dermatitis, atopic dermatitis/ allergy, seborrheic dermatitis, red, vesicular rash, spongiosis gives way to vesicles

Question 17

Contact dermatitis causes:

Answer 17

Detergent, nickel, poison ivy

Question 18

Rash not where the allergy is:

Answer 18

Atopic dermatitis/ allergy

Question 19

Atopic dermatitis/ allergy:

Answer 19

Often kids, cause unknown, genetic in some cases, stimulus: food or clothing?, Pt often has asthma, allergic rhinitis, often chronic w acute episodes

Question 20

Seborrheic dermatitis:

Answer 20

Stasis dermatitis (sluggish leg veins), drug reaction, type of eczematous rash, common, 5-10% of healthy, 1/3rd of AIDS pts, chronic, waxing and waning, hairy regions, esp face, eyebrows, scalp, around sebaceous glands, bilateral, symmetrical, itching variable, lipophilic yeast, Pityrosporum ovale, mildest form: dandruff; fine white scale, may have erythema, patches/plaques

Question 21

Tx for Seborrheic dermatitis:

Answer 21

Anti-fungal, shampoo 2-3 X wk, zinc pyrithione (Head and Shoulders), selenium sulfide, ketoconazole

Question 22

Inflammatory Scaling Papule & Plaques:

Answer 22

Dermatophytes, psoriasis, pityriasis rosea, 2’ syphilis, lichen planus

Question 23

Pityriasis rosea:

Answer 23

“bran-like scale”, young adults, seasonal, usually winter, often URI before, cellular Type IV immune response, antigen unknown, acute, self-limited, mostly trunk, neck

Question 24

Pityriasis rosea rash:

Answer 24

Herald patch (initial rapidly enlarging oval-shaped red papulosquamous lesion, usually trunk, heralding widespread eruption of pityriasis rosea in 7-14d), first, often largest, many lesions after several days, round to oval, tan/salmon color, look like bran/ corn flakes, itching is common, delicate scaling, elevated patches

Question 25

Ddx of Pityriasis rosea:

Answer 25

Psoriasis, lichen planus, tinea corporis (ringworm), 2’ syphilis

Question 26

Tx for Pityriasis rosea:

Answer 26

Usually spontaneous remission in 2-4wks, recurrence rare

Question 27

Lichen planus:

Answer 27

Cause unknown, probably immune-mediated, more common in women, Ig deposits at dermal-epidermal jx, some cases assoc w Hep C, involves skin & mucous membranes, oral lesions, 70% pts, esp. wrist and ankle, oral manifestation: red gum tissue, multiple lesions, purple, planar (flat) or papular, polygonal, pruritic (itchy), self-limited, resolves in mos-2yr, multiple papules w Wickham striae (whitish lines visible in papules of lichen planus and other dermatoses, typically the macroscopic appearance of the histologic phenomenon hypergranulosis), white dots = thickened granular layer

Question 28

Histology of Lichen planus:

Answer 28

Hyperkeratosis, thickened granular layer (almost diagnostic), irregular acanthosis (saw tooth D-E jx), band-like lymphocytic infiltrate (degeneration of basal layer)

Question 29

Vesicles of Lichen planus are often:

Answer 29

exanthems

Question 30

exanthems:

Answer 30

widespread rash usually occurring in children

Question 31

Possible causes of exanthems:

Answer 31

Varicella, herpes simplex, herpes zoster, enterovirus

Question 32

bullous/vesicular skin diseases (large, fluid filled) | hard or flaccid:

Answer 32

Pemphigus vulgaris, bullous pemphigoid, dermatitis herpetiformis (DH), porphyria, contact dermatitis, drug reaction/eruption, impetigo, scalded skin syndrome

Question 33

Pemphigus vulgaris:

Answer 33

Middle aged+, generalized bullae, anywhere on skin surface, oral lesions common, bullae flaccid, 1-10 cm, rupture easily → bleeding erosions → skin infection, mortality 8-10%, INTRAepidermal, suprabasilar bullae, only disease to have suprabasilar → DIAGNOSTIC, Begins w acantholysis, intercellular IgG, C3, autoantibodies to desmoglein 3 (adhesion molecule), Ab titer predicts course

Question 34

Tx for Pemphigus vulgaris:

Answer 34

Steroids

Question 35

only disease to have suprabasilar, DIAGNOSTIC:

Answer 35

Pemphigus vulgaris

Question 36

acantholysis:

Answer 36

loss of intercellular connections such as desmosomes resulting in loss of cohesion bw keratinocytes, not seen in bullous pemphigoid

Question 37

Autoantibodies to desmoglein 3:

Answer 37

located in desmosomes, Anti-desmoglein 3 Ab → Intercellular fluorescent deposits

Question 38

Bullous pemphigoid:

Answer 38

50-70yo, bullae in flexor areas (groin, axilla), ral lesions: 1/3 pts, very pruritic, tense bullae, 1-5 cm, heals wo scar, most subside in mo-1yr, subepidermal bullae, linear IgG, C3 at BM (lamina lucida), autoantibodies to hemidesmosome proteins, BP 180 and BP 230, intracellular and lamina lucida location, Ab binding to Ag seen in skin BM (LL – lamina lucida, LD - lamina densa), immunofluorescent deposits at BM (Only at the DE junction), like lichen planus, DM, SLE

Question 39

Rx for Bullous pemphigoid:

Answer 39

steroid, like pemphigus vulgaris

Question 40

Porphyria cutaea tarda:

Answer 40

Abnormal porphyrin metabolism (urodecarboxylase missing in cutaneous porphyria), most common porphyria, familial, autosomal dominant, uroporphyrinogen decarboxylase deficiency → build up of porphyrins, Dark brown urine; ↑ uroporphyrin, lesions precipitated by alcohol, sunlight, photosensitive skin lesions, esp hands (dorsum)

Question 41

Photosensitive skin lesions, esp hands (dorsum)

Answer 41

Subepi bullae, excess hair, esp forehead, temples, cheeks, neck

Question 42

Recap of pemphigoid:

Answer 42

tense bullae, subepidermal, Ig at BM, hemidesmosomes

Question 43

Recap of pemphigus:

Answer 43

flaccid ullae, suprabasillar, Ig are intracellular, desmoglein 3

Question 44

Recap of porphyria CT:

Answer 44

Tense bulla, subepidermal, Ig at De jx, absent UPDC

Question 45

These both have tense bullae and are subepidermal:

Answer 45

pemphigoid, porphyria

Question 46

Generalized erythema:

Answer 46

Drug eruption, Viral, Toxic, SLE, DM

Question 47

Viral, generalized erythema may be due to:

Answer 47

Rubella, measles, Roseola (HHV6), erythema infectiosum (parvo B19)

Question 48

Toxic, generalized erythema may be due to:

Answer 48

Scarlet fever-GAS, fever, pharyngitis (erythrogenic exotoxin, rash on face (circumoral pallor), arms, legs, trunk), scalded skin-Staph toxin, infants, fever, toxic shock syndrome-Staph and GAS

Question 49

Localized lesions w erythema:

Answer 49

Cellulitis, erysipelas-GAS, face, well-demarcated, fever, acute, swelling (type of cellulitis), rapid progression, impetigo- Staph/GAS, preschool children, face & neck, erythema nodosum, erythema multiforme, erythema migrans-Lyme disease

Question 50

Erythema nodosum:

Answer 50

Assoc w infections/immune mediated disease, type of panniculitis (subcutaneous), acute presentation (fever, malaise), often self-limited, but may be recurrent, rash: often lower legs (multiple, deep, tender nodules)

Question 51

infections/immune mediated disease assoc w erythema nodosum:

Answer 51

TB, sarcoidosis, IBD, beta strep infections

Question 52

panniculitis:

Answer 52

subcutaneous, below the skin- looks like a skin disease, but isn’t

Question 53

Tx for Erythema nodosum:

Answer 53

aimed at underlyling disease

Question 54

Early histo findings of Erythema nodosum:

Answer 54

polys, fibrin, deposits of Ig and C

Question 55

Semi-progressed histo findings of Erythema nodosum:

Answer 55

granulomatous inflammation, looks like TB

Question 56

Late histo findings of bands of Erythema nodosum:

Answer 56

bands of fibrosis

Question 57

Erythema nodosum is marked by chronic inflammation w this cell type:

Answer 57

giant cell

Question 58

Erythema mulitforme causes:

Answer 58

``` o Drugs • Sulfonamides, penicillins, salicylates o Infection, esp herpes simplex o Cancer o Collagen disease o Idiopathic ```

Question 59

Pathogenesis of Erythema mulitforme:

Answer 59

* Epidermal cells killed by T cells | * Cytotoxic CD8+ lymphocytes located at D-E jx

Question 60

population most affected by Erythema mulitforme:

Answer 60

older children, young adults

Question 61

Lesions of Erythema mulitforme:

Answer 61

Symmetrical, often extremities, classically look like a target (erythematous rim and center- diagnostic/signature lesion (esp if on extremities) )

Question 62

Histology of Erythema mulitforme:

Answer 62

Red, round, circumscribed, target-like, multiple, lymphocytes at D-E jx (migrate into epidermis, attack keratinocytes)