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Flashcards in Skin Deck (36):
1

Hyperkeratosis

More keratin = more cells in S. corneum.
(Psoriasis and Lichen planus.)

2

Parakeratosis

Retained nuclei in S granulosum, thinning, more turnover.
Psoriasis and dandruff.

3

Acanthosis

Thickening of S spinosum

4

Acantholysis

Lose desmosomes, so less cohesion between keratinocytes.
Pemphigus vulgaris.

5

Spongiosis

Intercellular oedema in epidermis.
Vesicles in eczema (dermatitis).

6

Histology of eczema/dermatitis

Acute: spongiosis, inflam infiltrate in dermis, dilated capillaries.
Chronic: acanthosis, crusting, scaling.

7

Clinical features of Atopic dermatitis (eczema)

Infants: face & scalp.
Children+ : Flexural areas. Lichenification if chronic.

8

Features of Contact dermatitis (eczema)

Erythma, swelling, pruritis.
Type IV hypersensitivity (nickel, rubber...), so affects ear lobes, neck, wrist, feet.

9

Features of Seborrhoeic dermatitis

Inflammatory reaction to the yeast Malassezia.
Infants: cradle cap.
Adults: mild erythema, fine scaling, mild pruritus - eyebrows, eyelids, ears, chest.

10

Layers of epidermis

S. corneum,
S. granulosum,
S. spinosum,
S. basale.

11

Histology of Psoriasis

Parakeratosis,
loss of S granulosum,
clubbed rete ridges ("test tubes in a rack"),
Munro's microabscesses.
Proliferation.

12

Associated features of Psoriasis

Nail changes: Pitting, Onycholysis, Subungual Hyperkeratosis;
Arthritis.

13

Psoriasis - commonest form, with appearance

Chronic plaque psoriasis.
Salmon pink plaques, silver scale, outside of knees, elbows, scalp.

14

Auspitz' sign

Pin-point bleeding in psoriasis

15

Koebner phenomenon

Linear lesions after trauma.
Seen in Psoriasis & Lichen planus (scratching),
and linear exposure to Molluscum & Warts.

16

Lichen planus lesions

Pruritic, Purple, Polygonal, Papules, Plaques.
Mother of pearl sheen, Wickam's striae.

17

Histology of Lichen planus

Hyperkeratosis,
saw-toothing of rete ridges,
basal cell degeneration.

18

Erythema multiforme appearance

Annular target lesions on hands and feet.
Pleomorphic (varied) lesions.

19

Causes of Erythema multiforme

Infections: HSV, mycoplasma;
Drugs: penicillin, salicylates, anti-malarials.

20

Nikolsky's sign

Exfoliation with light rubbing.
Seen in TEN/SJS and pemphiguS.

21

Sheets of skin detachment,

Stevens Johnson Syndrome

22

Sheets of skin detachment, >30% body SA

Toxic Epidermal Necrolysis

23

Causes of SJS/TEN

Drugs: sulfonamide Abx, anticonvulsants.

24

Pityriasis rosea

Salmon pink rash (herald patch), then oval macules in Christmas tree distribution.
After viral illness.
Remits spontaneously.

25

PemphiGoiD

Deep bullae (subepidermal). Robust.
IgG binds hemidesmosomes of basement membrane, linearly.
Elderly.
Eosinophils.

26

PemphiGuS

Superficial bullae pop.
Skin and mucosal membranes.
IgG binds desmosomal proteins inside epidermis.
Net-like pattern. Acantholysis.

27

DermAtitis herpetiformis

Itchy vesicles outside elbows. (Bullous.)
Subepidermal bullae (like pemphigoiD).
IgA binds basement mebrane: Neut & IgA at tips of dermal papillae.
Assoc: Coeliac.

28

Seborrhoeic keratosis

Benign.
Rough waxy plaques, "stuck on".
Elderly.

29

Actinic keratosis

= Solar.
Premalignant.
Rough sandpaper.
Sun.
Spain: Solar elastosis, Parakeratosis, Atypical cells, Inflam, Not full thickness.

30

Bowen's disease

Pre-malignant - intra-epidermal SCC in situ.
Flat red scaly patches. Sun.
Full thickness, but BM intact.

31

Keratoacanthoma

Rapid dome, ?necrotic centre.
Clears after 2-3 weeks of growth.
Looks like SCC.

32

SCC

Bowen's has involved dermis. May ulcerate.
Atypical cells spread through dermis.

33

BCC

Rodent ulcer. Pearly. Telangectasia.
Slow. Rarely metastatic.
Mass of basal cells push into dermis.

34

Melanocytic naevus

Benign melanoma

35

Breslow thickness

Stage / prognosis of Malignant melanoma

36

Malignant melanoma histology

Atypical melanocytes.
First grow horizontally - radial.
Then vertically, showing Buckshot (scatter) appearance.