Psoriasis Flashcards
(33 cards)
Explain 6 ways in which psoriasis affects nails
1 m/c nail finding → thimble pitting
2 onycholysis → separation of nail from nail bed
3 salmon patches of nail bed
4 subungual hyperkeratosis → keratinous material under nail plate
5 oil drop sign → staining of nail bed
6 thickening & tunneling of nail plate
Define psoriasis
Genetically determined
T cell mediated
Chronic
Relapsing
Skin dis
Unknown etiology
Define lesions?
Skin lesions are → erythrosquamous
Means it involves both > vasculature (erythema)
> epidermis ( increased scale formation)
Worsens in winter
+ve family history in > 50%
HLA asso.?
HLA CW 6
What is basic underlying pathologic defect ?
Increased epidermal proliferation rate
Normal skin →27 days.
Psoriatic skin → 4 days
Aggravating factors?
Sepsis
Stress
Cold injury» shivering
Trauma
Drugs → beta blockers
lithium
Antimalarial’s
ibuprofen
stoppage of steroids
Histo features?
Munro microabstasses → neutrophils in stratum corneum
Spongiform pustules of kogoj → neutrophils in stratum spinosum
Parakeratosis
Absent granular layer
Lesion looks like?
Does it itch?
Silvery mica scales → scales typically absent in groin & flexures
As epidermal mass is increased 3-5 times
Mild / No itching » variably pruritic
Onset?
Gender preponderance?
2nd-3rd decade
More common in males
Common sites?
Extensor aspects → elbow, knees, trunk » back & lumbo sacral area
scalp, hands
Signs in psoriasis?
Auspitz sign
Bulkeley’s membrane
Grattage test
Woronoff’s ring
Köbner / isomorphic phenomenon
Candle grease sign (tache de bougie)
Describe auspitz sign
When scales are scrapped → pinpoint bleeding » from dilated superficial capillaries occurs through Bulkeley’s membrane
Describe Bulkeley’s membrane ?
Removal of scales reveal a glistening red membrane of bulkeley
Grattage test
On scratching the lesion → mila like scales appear
Woronoff’s ring?
Whitish halo around the lesion
Koebner /isomorphic phenomenon?
Traumatised areas → start developing lesions
Candle - grease sign aka Tache de bougie
When lesion scratched with point ofdissecting forceps → candle like grease scale can be repeatedly produced even from non scaling lesions
Does it involve joints?
Yes
30%» pts. Have psoriatic arthritis
90% pts. Of psoriatic arthritis have nail changes
Psoriatic arthritis
Doc?
Features?
X-ray signs?
Doc → methotrexate
Features: dip involvement
dactylitis » sausage digits
arthritis mutilans
severe destructive arthritis
X-ray signs: opera glass hand, pencil in cup app, whiskering
Describe opera glass hand? See img
Telescoping of one bone into its neighbour with shortening of digits
Pencil in cup app? How it looks? See img
Tapering → proximal phalanx
Proliferation → distal terminal phalanx
Whiskering is?
Marginal erosions with adjacent proliferation
Name → types of psoriasis?
See img of lesions? - from AIIMS essence
Stable plaque psoriasis
Rupioid psoriasis
Guttate / eruptive/raindrop psoriasis
Inverse / seborrrheic psoriasis
Pustular psoriasis
Erythrodermic psoriasis
General pustular / Von zumbusch psoriasis
Impetigo herpetiformis
Stable plaque psoriasis
M/C type of psoriasis
Involves → elbows, knees, lower back, scalp, nails, napkin area
Infant may present as » ‘nappy rash”
