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Flashcards in Skin Path Deck (20):
1

Define these key terms:

  • hyperkeratosis
  • parakeratosis
  • acanthosis
  • acantholysis
  • spongiosis
  • lentiginous 

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  • Hyperkeratosis - thickening of S. corneum; often increased keratin
  • Parakeratosis - retention of nuclei in S. corneum - seen in disorders of increased cell turnover
  • Acanthosis - increase in S. Spinosum
  • Acantholysis - reduced cohesion between keratinocytes
  • spongiosis - intercellular oedema
  • Lentiginous - linear pattern of melanocyte proliferation within epidermal basal cell layer 

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2

Eczema/ dermatitis: 

  1. atopic
  2. contact
  3. seborrhoeic 

Give 1 characteristic of each

they all have similar histology & present with inflamed, dry itchy rashes

  1. atopic - FHx of atopy
    • affects flexural ares in older children
    • if chronic get lichenification
  2. Contact - type IV hypersensitivity
    • erythema, swelling, pruritis 
  3. Seborrhoeic = inflammatory rxn to a yeast (malassezia)
    • infants - cradle cap. Fine scaling in young adults

 

3

Eczema/ dermatitis: all types have same histology, descibe the acute (2) & chronic (1) 

acute

  • spongiosis - intercellular oedema
  • inflammatory infiltrate  in dermis - eosinophils
  • dilated dermal capillaries

Chronic

  • acanthosis 
  • crusting/ scaling

4

Psoriasis:

  • what is it?
  • extensor of flexors affected?
  • what is auspitz sign?
  • what is koebner phenomenon?

  • Chronic inflammatory dermatosis, charactereized by well demarcated red scaly plaques
  • affects extensors (in contrast to eczema) 
  • auspitz sign - pin point bleeding where you rub them
  • koebner phenomenon​ - lesions grow at site of trauma

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5

Psoriasis - histology (2)

  • parakeratosis - retention of nuclei (due to increased cell turnover)
  • "test tubes in a rack" appearance - due to clubbing of rete ridges
  • munro's microabscesses 

6

Most common form of psoriasis is chonic plaque psoriasis, other forms include:

  1. Flexural psoriasis
  2. Guttate psoriasis
  3. Pustular/ erythodermic psoriasis

1 feature of each

  1. flexural - seen later in life
  2. Guttate - rain drop lesions seen in children post strep
  3. pustular - severe wide spread disease with systemtic symptoms

7

What nail changes are often seen with psoriasis? (3)

Nail changes: (POSH)

  • Pitting
  • Onycholysis
  • subungual hyperkeratosis

NB - psoriasis also assc with arthiritis 

8

Lichen planus: 

  • 5 Ps describing lesions
  • what are Wickam's striae?
  • Histology (2)

Aetiology is unknown - thought to be T cell derived

Lesions are 'pruritic, papules, purple, polygonal & plaques'

Wickam's striae - forms white lines - often in mouth

Histo

  • hyperkeratosis
  • saw toothing of rete ridges
  • destruction of basal keratinocytes  

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9

Erythema multiforme:

  • classic lesions 
  • causes (2)
  • histology (1)
  • if in mouth associated with which emergency?

  • classically causes annular target lesions, commonly on hands and feet
  • Causes - infection or drugs
  • histo - subepidermal bullae 
  • if in mouth assc with SJS 

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10

Bullous disease: Pemphigoid

  • patthophysiology
  • features (1)
  • histology (2)

Path - IgG binds to hemidesmosomes of BM > subepidermal bullae 

F - usually in elderly, large bullae

Hist - subepidermal bullae with eosinophils, linear deposition of IgG along BM 

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11

Bullous disease: pemphigus vulgaris

  1. pathology
  2. Feature (1)
  3. histology (2)

Path - IgG bind to desmosomes - intraepidermal bullae

(pemphigus - bullae are superficial, pemphigoid - bullae deep)

F - bullae easily ruptured

Hist - intraepidermal bullae, net like pattern of intercellular IgG deposits, acantholysis 

12

Bullous disease: Dermatitis herpetiformsis 

  • assc with?
  • which Ab class & what does it bind ?
  • features? (1)

It is associated with coeilacs, get IgA abs binding to BM - subepidermal bullae

F - itchy vesicles on extensor surfaces of elbows

13

Seborrhoeic keratosis: features (2)

Benign lesion - rough plaques, waxy 'stuck on' appearance, elderly 

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14

Actinic keratosis: features (2), hitology (5)

Is a premalginant, Rough sand paperlike scaly lesion in sun exposed areas

Histo: SPAIN

  • Solar elastosis
  • Parakeratosis
  • Atypia/dysplasia
  • Inflammation
  • Not full thickness

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15

Bowen's disease: what is it? features (2), histology (2)

intra-epidermal carcinoma in situ

flat, scaly patches on sun exposed areas

Histo:

  • Full thickness dysplasia
  • doesent invade BM - so not a cancer (premalignant) 

16

Squamous cell carcinoma: characteristics (1), histo (2)

This is basically when Bowen's disease has penetrated the BM

clin features similar to Bowen's, but SCC may also ulcerate

histo - fullthickness dysplasia penetrating BM into dermis 

17

BCC: characteritisics (3), histo (1)

AKA rodent ulcer

Slow growing, not metastatic cancer - but locally destructive

pearly surface, telangiectasia

Histo - mass of basal cells pushing down into dermis 

18

Malignant melanoma: histo (2), staged using? 

Histo - atypical melanocytes

  • 1st grow horizontally in epidermis - radial growth phase
  • Then vertically into dermis - vertical growth phase

staged - Breslow thickness - most imp prognostic factor

 

19

Give the 4 subtypes of malignant melanomas, and 1 feature for each

  1. Lentigo MM - sun exposed areas of elderly
  2. Superficial spreading MM - irregular borders + colour variation
  3. Nodular MM - in young ppl
  4. Acral lentiginous melanoma - palms/soles & subungual areas 

20

SJS: features (3), cause (1)

Derm emergency

F - sheets of skin detachment - <10% SA for SJS, > 30% in TEN

Nikolsky sign +ve (skin can be pushed aside by slight pressure from fingers), mucosal involvment

Cause - Drugs eg. sulfonamide ABs, anticonvulsants