pathology 1 Flashcards
name the 7 functions of the skin?
Barrier thermoregulation Fluid and electrolyte balance Endocrine function (UV => vit D) Protection from UV rays Immune sensory
Epidermis
- type of epithelium?
- 4 types of cells
- 4 layers in order
-stratified keratinising squamous epithelium
-prickle cells, prominent desmosomes
corneocytes, shed from surface
melanocytes, basal layer, transfer pigment to keratinocytes via dendritic processes
langerhans, in upper and mid epidermis and act as sentinels
-Keratin layer
Granular layer
Prickle cell layer
Basal layer
Dermis
- composed of?
- 2 layers?
-type 1 and 2 collagen
-Papillary, thin and beneath epidermis
Reticular, thicker bundels type 1 collagen and contains appendages
Definition of:
- Hyperkeratosis
- Parakeratosis
- Acanthosis
- Papilomatosis
- Spongiosis
- increased thickness of keratin layer
- persistence of nuclei in the keratin layer
- increased thickness of the epithelium
- irregular epithelial thickening
- odema in epidermis
Name the 4 different types of inflammatory skin disease
- describe
- give examples
Spongeotic
-intra epidermal oedema e.g. eczema
Psoiasiform
-elongation of rete ridges e.g. psoriasis
Lichenoid
-basal layer damage e.g. lichen planus
Vesiculobullus
-blistering e.g. pemphigoid
Psoriasis
- what is it?
- effect on epithelium?
- What occurs in trauma?
- pathophysiology?
- Appearance?
- complication
- Chronic inflammatory Dermatosis
- Epidermal hyperplasia with increased epidermal turnover
- new lesions at site, Koebner Phenomenon
- complement mediated attack of the Keratin layer, this attracts neutrophils and causes munro micro abscess formation
- raised, silvery scale, well demarcated border with pinpoint bleeding
- Erythrodema
Acne
- distribution? why?
- Aetiology (5), increase in what…?
- Bacteria assoc?
-Face, neck, upper back and chest
sebaceous glands located here
- Increased androgens at puberty
- increased sebaceous gland sensitivity to androgens
- Keratin and sebum plug the pilosebaceous units and cause comedone formation
- Infection with anaerobic bacterium
- Rupture causes acute inflammation and foreign body granulomas
-corynebacterium acnes
Rosacea
- what is it?
- triggers?
- 5 pathological signs
- recurrent facial flushing with visible blood vessels + pustules and thickening of the skin causing rhinophyma
- sunlight, spicy food, alcohol, stress, tetracyclines
-Vascular ectasia patchy inflammation with plasma cells pustules perifollicular granulomas Follicular demodox mites
Name 3 immunobullous diseases
- main feature?
- genetics?
- what is it?
- controlled?
pemphigus vulgaris
bullous pemphigoid
Dermatitis herpetiformes
- blisters are the primary feature
- rare and autoimmune
- loss of integrity of epidermal cell adhesion
- steroids
Pemphigus Vulgaris
- antibody involved
- pathophysiology (4)
- presentation
-IgG autoantibodies made against desmoglein 3
-immune complexes from on the cell surface
compliment activation
protease release
Disrupts desmosomal attatchments
causes acantholysis (lysis of intracellular adhesion sights)
-fluid filled blisters, may rupture to form erosions
Bullous pemphigoid
- Antibodies
- pathophysiology
- presentation
- investigations and findings
-IgG autoantibodies
-attack hemidesmosomes anchoring basal cells to basement membrane
local complement activation causes tissue damage
- sub epidermal blisters with no signs of acantholysis
- immunoflourescence shows linear IgG
Dermatitis herpetiformes
- antibodies?
- pathophysiology
- Associated with?
- genetics?
- presentation- distribution?
- pathological hallmark?
-IgA antibodies, target Gliadin
-Antibodies cross react with connective tissue matrix
form immune complexes in dermal papillae
complement activated
- coeliac disease
- HLA-DQ2 Haplotype
- Intensely itch lesions, symmetrical often on knees, elbows and buttocks
- papillary dermal micro-abscesses
