Skin conditions (not infectious)

Question 1

Psoriasis pathophys

Answer 1

Chronic TH1 mediated cutaneous inflammation and hyperproliferation
TH1 cells produce cytokines IL2, TNFa, IL8 which attract and activate neutrophils

Question 2

Histology of psoriasis

Answer 2

elongated rete redges
hyper and parakeratosis
neutrophils in epidermis
Auspitz

Question 3

Clinical features of psoriasis

Answer 3

5 cardinal features: plaques, well circumscribed, bright salmon red colour, silevry micaceous scale, symmetric
extensor surfaces over bony prominences
nails: pitting, onycholysis, serous exudate, shedding, subungual hyperkeratosis
increased risk of cardiac events

Question 4

Guttate psoriasis

Answer 4

acute extensive psoriatic papules over trunk and proximal extremities
usually associated with group A strep

Question 5

Inverse psoriasis

Answer 5

flexural sites
lack scales
bright red, moist, macerated appearance

Question 6

Pustular psoriasis

Answer 6

generalized pustular = fever, leukocytosis, life-threatening

localized - palms and soles

Question 7

Erythrodermic psoriasis

Answer 7

entire body

red and scaly, prominent systemic complications

Question 8

Dx psoriasis

Answer 8

clinical

Question 9

Tx psoriasis

Answer 9

topical: GCs, tars, salicylic acid
phototherapy: UVB
Systemic (for recalcitrant disease): methotrexate, oral retinoids (acetretin), cyclosporine, biologics

Question 10

Lichen planus pathophys

Answer 10

unknown

unrelated to any fungal/lichen infection

Question 11

Lichen planus histology

Answer 11

dense band-like lymphocytic infiltrate at dermo-epidermal junction
basale destruction
hypergranulosis
hyperkeratosis

Question 12

Lichen planus clinical features

Answer 12

5Ps: papule, pruritis, purple, polygonal, planar (flat-topped)
Wickman’s stria (whitish scale)
Oral mucosal lesions extremely common (lacy white lesions on buccal mucosa)
may be associated with Hep C
slow onset

Question 13

Lichen planus Dx

Answer 13

clinical

Question 14

Lichen planus Tx

Answer 14

1) topical steroid
2) topical retinoids
can use oral antihistamines to relieve severe itch

Question 15

Pityriasis rosea pathophys

Answer 15

may be due to human herpesvirus infection; self-limit

Question 16

Pityriasis rosea histology

Answer 16

parakeratosis, spongiosis

Question 17

Pityriasis rosea clinical features

Answer 17

herald patch - solitary 2-6 cm scaly plaque
fine collarette scaling along rim of individual lesions
T shirt and shorts distribution
Mimicked by secondary syphilis (do VDRL) and drug eruptions

Question 18

Pityriasis rosea Dx, Tx

Answer 18

clinical diagnosis

Tx usually not necessary

Question 19

Eczema/atopic dermatitis pathophys

Answer 19

TH2 mediated cutaneous inflammation, possible S. aureus skin infection
impaired cutaneous barrier function
also allergic contact dermatitis, irritant contact dermatitis

Question 20

Eczema histology

Answer 20

elonged rete ridges
hyper and parakeratosis
epidermal lymphocytes and Langerhans cells
spongiosis

Question 21

Eczema clinical features

Answer 21

intense pruritis
not well-circumscribed
commonly secondary lesions seen due to rubbing (lichenification), excoriations

Question 22

Eczema phases

Answer 22

infantile - facial and extensor
Childhood - flexural distribution, secondary lesions prominent
adult - improve gradually, may remit

Question 23

Eczema tx

Answer 23

aggressive restoration of cutaneous permeability barrier (emollients, moisturizer)
1) topical GC
2) topical immunomodulators
oral antihistamines

Question 24

Acne pathophysiology

Answer 24

inflammation of pilosebaceous units associated with formation of comedones
abnormal follicular keratinization, sebum overproduction, overgrowth of follicular bacteria (P. acnes)

Question 25

Acne histology

Answer 25

neutrophil infiltration of pilosebaceous unit plugging of hair follicle with keratin fibroblastic and collagen proliferation in normal derma structures

Question 26

Acne clinical features

Answer 26

``` most commonly found in areas of the most sebaceous secretion (face, shoulders, upper back, upper chest) closed comodones (white heads) and open comedones (black heads) - closed comedones more likely to give rise to inflammatory lesions ```

Question 27

Mild acne

Answer 27

mostly comedones, few inflammatory lesions, no scars

Question 28

Moderate acne

Answer 28

comedones, papules and pustules, no deep cysts or nodules

Question 29

Severe acne

Answer 29

cysts or nodules, significant scarring

Question 30

Acne tx

Answer 30

1) gentle cleansing BID 2) retinoic acid, antibiotics, benzoyl peroxide, salicylic acid oral: systemic isoretinoin (retinoic acid) antibiotics (relapse is common)

Question 31

Rosacea pathophys

Answer 31

unknown papulopustular components centred on the pilosebaceous unit but underlying abnormalities are vascular, not follicular in origin

Question 32

Rosacea histology

Answer 32

inflammatory periadnexal infiltrates occasional parasitic infestations of follicles (Demodex) sebaceous hyperplasia

Question 33

Rosacea clinical features

Answer 33

``` commonly middle-aged type 1: Erythematotelangiectatic rosacea 2: papulopustular rosacea 3: phymatous rosacea (develop rhinophyma 4: ocular rosacea (conjunctivitis, blephoritis, iritis, keratitis) ```

Question 34

Rosacea dx

Answer 34

clinical | DDx acne vulgaris

Question 35

Tx rosacea

Answer 35

avoid triggers - sun, heat, alcohol laser ablation for telangiectasia tetracyclines and cold compress for erythema metronidazole, azaleic acid, systemic antibiotics for papulopustular systemic tetracyclines and isotretinoin = moderately effective for phymatous rosacea

Question 36

Pemphigus pathophys

Answer 36

rare antibody-mediated vs antigen important in allowing keratinocytes to adhere (intraepidermal split) fluid accumulates in intraepidermal split - clinically apparent fragile bullae

Question 37

Pemphigus histology

Answer 37

suprabasal intraepidermal cleft

Question 38

Pemphigus clinical features

Answer 38

easily ruptured bullae | flaccid erosions common

Question 39

Pemphigus tx

Answer 39

topical/systemic steroids | immunosuppressives (methotrexate)

Question 40

Bullous pemphigoid pathophys

Answer 40

antibodies to antigens in basement membrane zone between epidermis and dermis

Question 41

Bullous pemphigoid histology

Answer 41

inflammatory infiltrate of eosinophils near dermo-epidermal junction subepidermal split full thickness of epidermis above fluid accumulation

Question 42

Bullous pemphigoid histology clinical features

Answer 42

``` pruritic erythematous plaques tense bullae (not fragile) with few erosions ```

Question 43

Bullous pemphigoid treatment

Answer 43

better prognosis than pemphigus vulgaris | prednisone; IVIG or rituximab if refractory

Question 44

Drug eruptions pathophys

Answer 44

undesirable response to medication at a certain dose

Question 45

Drug eruption clinical features

Answer 45

urticaria maculopapular/morbilliform (measles-like) localized inflamed plaques that recur at same body site each time patient is exposed

Question 46

Exacerbating factors for psoriasis

Answer 46

``` Koebner phenomenon Infections (GAS, HIV) dry air/skin stress alcohol and drugs - flareup after discontinuation of prednisone - lithium, beta blockers - any cutaneous drug eruption ```

Question 47

Ameliorating factors for psoriasis

Answer 47

sunbathing (UVB immunosuppression) | moisturizes

Question 48

Pregnancy - benign skin changes

Answer 48

Striae gravidarum Hyperpigmentation at areola, axillae and genitals increase or decrease in growth and production of hair nails usually grow faster vascular changes - spider telangiectasias, palmar erythema, saphenous, vulvar, or hemorrhoidal varicosities Preexisting skin conditions may change Atopic dermatitis/psoriasis may worsen or improve; psoriasis more likely to improve Fungal infections generally require longer treatment course during pregnancy

Question 49

PUPPP

Answer 49

Pruritic urticarial papules and plaques of pregnancy - intense pruritis, develops in the 3rd trimester and generally first appears on abdomen often along striae and occasionally involves extremities face spared

Question 50

Prurigo of pregnancy

Answer 50

erythematous papules and nodules on extensor surfaces of extremities

Question 51

INtrahepatic cholestasis of pregnancy

Answer 51

intrahepatic cholestasis occurring in the 3rd trimester | results in excoriation from scratching with non-specific distribution

Question 52

Pemphigoid gestationis

Answer 52

AI skin disorder in mid to late term pregnancies with linkage to HLA-DR3 and DR4 can take variable course although it generally improves in late pregnancy with exacerbations in the immediate postpartum period pruritic papules, plaques and vesicles evolving into generalized vesicles or bullae Initial periumbilical lesions may generalize although face, scalp and mucous membranes usually spread

Question 53

Impetigo herpetiformis

Answer 53

pustular psoriasis that is a rare skin disorder in the 2nd half of pregnancy round, arched or polycyclic patches covered with small painful pustules in a herpetiform pattern most commonly appears on thighs and groin but rash may coalesce and spread to trunk and extremities face, hands and feet are spared but mucous membranes may be involved

Question 54

Pruritic folliculitis of pregnancy

Answer 54

occur in 2nd and 3rd trimester and present as erythematous follicular papules and sterile pustules on abdomen, arms, chest and back CONTRARY TO ITS NAME purities is not a major feature