Psoriasis
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Transcript of Psoriasis
Psoriasiform Lesions
Some things common
Epidermal hyperplasia
Elongation of rete ridges
Psoriasis
Psoriasis
Greek word for 'itch'
“chronic
non-infectious
erythematous plaques & papules
silvery scales
extensor distribution”
Psoriasis vulgaris
(common)
Chronic RelapsingPapulosquamous dermatitis
Incidence : 2 %
All Races
More in western people
Mean age - 25 yrs
Chr - 6P21.3
Associated with - HLA-CW0602
(PCR)
How the patient presents ?
Erythematous plaques with
Silver scaling
When the scales are removed …
It bleeds
Auspitz’s sign
Capillaries
Scratch
Which sites are involved ?
Scalp ,
Lips no involved
Oral lesions are rare
5 % cases --- Polyarthritis
Do we know the Cause ?
Trigger factors
TraumaInfectionDrugs : Lithium, iodine , B blockers, Carbamazepine, NSAIDS, ACE inhibitorsClimateHormone, Stress AlcoholSmoking
Lesions after Trauma
(Koebner phenomenon)
30 % cases.
What is the Pathogenesis ?
YY YIts an Immune reaction
“Problem in signal transduction”
Initiation
Cytokine
transcription regulation
problems
Stimulation of immunity by
super antigen
• Problem in signal transduction in between the cells
• Cytokine transcription regulation problems
• Stimulation of immunity by super antigen
Initiation
Blood vessels in the papillary dermis
Disease process starts here
Blood vessels in the papillary dermis
Dilatation and tortuosity
Angiogenesis (TGF alfa, IL 8 )
Size of microcirculation Expands
New vessels bring T lymphocytes
Lymphocyte recruitment in papillary dermis
(PAF, LB4)
Lymphocytes come and bind to endothelial
cells in venules of papillary dermis
Even the expression of
adhesion molecules is
increased (E selectin)
E selectin correlates with the disease process UV rays decrease adhesion molecules! (PUVA therapy !!)
Now the Lymphocytes come out
of the venules (C5a)
CD4 or CD8 ?
CD4 in the dermis
CD8 migrate to the epidermis
Mechanism
T cell activation by super antigen
Release of huge quantity of cytokines
Transit time change
53 days
in Psoriasis
7 days
Histopathology
Early changes
Dilatation and congestion of vessels
Mild perivascular lymphocytic infiltration