histopathology of vasculitis and blistering diseases

Question 1

what are the vascular components in the skin (4)

Answer 1

1. papillary loops
2. superficial vascular plexus
3. deep vascular plexus capillaries around hairs and glands
4. subcutaneous vascular plexus

Question 2

what is vasculitis

Answer 2

inflammation of vessels

Question 3

which vascular layer is responsible for vasoconstriction in the skin

Answer 3

subcutaneous vascular plexus

Question 4

what key roll does the lymphatic system play in the skin

Answer 4

collects interstitial fluid and delivers it to the venous system

Question 5

what is leukocytoclastic vasculitis

Answer 5

a small vessel vasculitis characterized histopathologically by immune complex-mediated vasculitis of the dermal capillaries and venules

Question 6

what 2 cells have the ability to move locations in the body

Answer 6

neutrophils; histeocytes

Question 7

large vessel vasculitis examples

Answer 7

granulomatous disease - GCA, takayasu ateritis

Question 8

medium vessel vasculitis types + examples (2)

Answer 8

1. immune complex mediated (polyarteritis nodosa)
2. anti-endothelial cell antibodies (kawasaki disease)

Question 9

small vessel vasculitis types + examples (7)

Answer 9

ANCA assoicaited:
1. vasculitis without granulomas (microscopic polyangitis)
2. granulomas (Wegener granulomatosis)
3. eosinophilic granulomatous (chrug-strauss)

immune complex mediated:
1. SLE
2. IgA (henoch-schonlein purpura)
3. cryoglobulin
4. other (e.g. goodpasture disease)

Question 10

how do granulomas form in large vessel vasculitis

Answer 10

inflammatory cells try to destroy the offending agent, if unsuccessful then histocytes form a wall around it instead

Question 11

examples of C-ANCA vasculitis

Answer 11

Wegener granulomatosis (granulomatous polyangiitis)

Question 12

exmples of P-ANCA vasculitis

Answer 12

microscopic polyangiitis (MPA); eosinophilic granulomatosis with polyangiitis (EGPA = churg-strauss)

Question 13

presentation of cutaneous small vessel vasculitis

Answer 13

non-blanching blotchy haemorrhages

Question 14

apart from the skin, where else can early signs of vasculitis be detected

Answer 14

high blood flow organs e.g. kidneys

Question 15

what happens to the vessel walls after they are damaged

Answer 15

fibrosis - fibrin tries to plug the holes in the vessel walls

Question 16

why do blisters from

Answer 16

hydrostatic pressure (usually) overcomes the adhesion of the skin layers - can be intraepidermal or subepidermal

Question 17

in bullous pemphigoid what proteins ae responsible for illiciting the reaction seen

Answer 17

BP230 and BP180

Question 18

what layers are split apart in bullous pemphigoid

Answer 18

keratinocytes and the basement membrane

Question 19

atypical desmoglein 3 causes what disease

Answer 19

pemphigus vulgaris

Question 20

pemphigus foliaceous vs pemphigus vulgaris

Answer 20

foliaceous - does not involve mucosal lesions and only involves skin involvement, only desmoglein 1 is affected and so it is only the skin region that cant compensate (desmoglein 3 and 1 are both present in the mucous so desmolgein 3 can compensate and the mucous is not affected - see lect)

vulgaris - involved mucosal membranes, gradient of desmolgein distribution in the mucousal layers results in lack of compensation when desmolgein 3 is damaged

Question 21

how does adhesion fail in pemphigus vulgaris

Answer 21

antigens cover the surface of desmolgein 3, preventing adhesion of the molecules together and so the cells are not adhered to the intra-cellular space