Histopathology 6 - Skin pathology Flashcards
Where does the dermis sit relative to the basement membrane?
The dermis sits below the BM
What features are seen in the dermis layer?
Blood vessels, sweat glands, hair follicles, sebaceous glands and nerve fibres
Layers of skin “come lets get some beers”
Stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale
Features of palmar-plantar skin
No sebaceous glands, very thick corneal layer
Name 3 vesiculobullous skin diseases
Bullous pemphigoiD
Pemphigus vulgariS
Pemphigus folliaceous
Clinical features of bullous pemphigoid
Elderly, flexural surfaces, tense bullae
What would be seen on immunofluorescence of patient with bullous pemphigoid?
IgG and C3 deposition at dermoepidermal junction
Pathophysiology of bullous pemphigoid
Autoimmune disorder caused by IgG and C3 attack of the basement membrane, causes the epidermis to lift off the BM. Eosinophils also recruited which cause further damage to anchoring proteins which are anchoring the lower keratinocytes to the BM. (anti-hemidsemosome IgG)
Clinical features of pemphigus vulgaris
Flaccid blisters which rupture easily
Pemphigus vulgaris pathophysiology
IgG antibodies attack between the keratinocyte layers (Acantholysis) –> IgG deposits in epidermo-epidermal junction (need immunofluorescence to confirm diagnosis)
Which is most superficial of the vesiculobullous conditions?
Pemphigus foliaceous
Pemphigus foliaceous pathophysiology
IgG against desmoglein of the stratum corneum, v thin top layer of skin
Diagnosed with immunofluorescence
Pattern of inflammation in eczema
Spongiotic as you get oedema between the keratinocytes
Pathophysiology of psoriasis
Much faster turnover of keratinocytes –> thickened epidermis + layer of parakeratosis at the top
The inflammatory cell in eczema and psoriasis, respectively
Eczema: eosinophils
Psoriasis: Neutrophils
Which layer of skin disappears in psoriasis?
Stratum granulosum, there is not enough time for it to form
What are Munro’s micro abscesses and what condition are they seen in’/
In psoriasis, neutrophil recruitment forms Munro’s micro abscesses
Which cell mediates lichen planus?
T cell mediated
How does lichen planus appear on the wrist and how does it appear in the mouth?
on wrist = purple/red papule and plaques
Mouth: white lines known as WICKHAM STRIAE
Pathophysiology of lichen planus
T-cells have destroyed bottom keratinocytes –> band-like inflammation
Pyoderma gangrenosum type of disease
Vasculitis, not gangrenous
“stuck on” appearance + benign
Seborrhoeic keratosis
What kinda cysts are seen in seborrheic keratosis
Keratin “horn” cysts
Name a disease which is a pre-malignant skin neoplasm?
Bowen’s disease (SCC in situ)
