Term
epidemiology of psoriasis
-age of onset
-peaks of occurence |
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Definition
-average onset 33 years
-two peaks: 22.5 years, 55 years
-earlier onset (<15 years) correlated with worse disease and family history |
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Term
| comorbidities with psoriasis |
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Definition
systemic diorders
-Chron's
-metabolic syndrome
-depression
-cancer (skin, lymphoma)
*moderate and severe psoriasis patients have increased risk of CV disease*
-may be due to circulating proinflammatory factors that may lead to damage of endothelial blood vessels |
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Term
| subtypes/variants of psoriasis |
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Definition
chronic plaque
inverse
guttate (eruptive)
erythrodermic
pustular
variants may coexist in one person
nails and joints can often be involved |
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Term
chronic plaque psoriasis
clinical features |
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Definition
most common variant
-itchy
-thick, raised plaque
-sharp demarcation
-erythematous under scale
-silvery scale
-Auspitz sign |
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Term
|
Definition
| pinpoint hemorrhage seen when scale removed because there are many elongated and dilated blood vessels in the upper dermis |
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Term
chronic plaque psoriasis
common locations |
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Definition
SCALP
ELBOWS
KNEES
also: gluteal cleft, hands & feet, retroauricular, periumbilical
often shows SYMMETRIC involvement |
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Term
|
Definition
| ~25% of patients will develop psoriasis in areas of prior skin injury (trauma, sunburn, drug eruptions, viral exanthems) |
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Term
inverse psoriasis
clinical features |
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Definition
sharply demarcated, raised, glossy erythema
absent scale because located in skin folds (moisture) |
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Term
inverse psoriasis
common locations |
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Definition
skin folds:
-axillae
-genital, gluteal
-inframammary |
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Term
eruptive/guttate psoriasis
clinical features |
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Definition
multiple papules <1cm
classically follows infection with strep pharyngitis and seen in younger patients
(much better prognosis) |
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Term
eruptive/guttate psoriasis
common locations |
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Definition
| upper trunk and proximal extremities |
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Term
erythrodermic psoriasis
clinical features |
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Definition
generalized disease - total body involvement: eryhtema, scaling
hospitalization; fever/chills, fluid imbalance, electrolyte imbalance |
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Term
pustular psoriasis
clinical features |
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Definition
generalized or localize forms
sterile pustules on red skin (no silver plaques)
systemic: fever, weight loss, increased WBC, hypocalcemia, elevated ESR
reason to hospitalize |
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Term
| triggers of pustular psoriasis |
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Definition
pregnancy
systemic corticosteroid withdrawal
infection |
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Term
|
Definition
present in up to 80% of patients
fingers > toes
pitting: most common finding
oil spots: psoriasis under nail plate
onycholysis: separation of plate/bed
anonychia: complete nail loss, pustular involvement |
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Term
|
Definition
seronegative arthritis in up to 30% of patients
usually *asymmetric oligoarthritis* |
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Term
|
Definition
thick epidermis with elongated rete ridges from increased epidermal proliferation
scale from abnormal keratinocyte differentiation with retention of many dead keratinocytes
redness from elongated and dilated blood vessels in upper dermis
many inflammatory cells present: T-cells and dendritic cells, usually found around blood vessels |
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Term
| factors contributing to the pathogenesis of psoriasis |
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Definition
-multi factorial disease
-maybe autoimmune/autoinflammatory
-genetics
-immune factors
-environmental factors |
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Term
| genetic contributions to psoriasis |
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Definition
-inheritance of many genes PLUS environmental triggers is key
-positive family history in 35-90%
-MZ>DZ risk |
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Term
| specific gene involvement |
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Definition
linkage gene studies have identified:
*PSORS1* key chromosomal locus
*HLA-Cw6* gene at PSORS1 locus
associated with 13x increased risk and with early onset and guttate/eruptive types |
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Term
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Definition
numerous elements of the immune system are involved
activated Tcells
cytokines |
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Term
| evidence for T cell involvement in psoriasis |
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Definition
psoriasis is T-cell mediated
numerous T cells can be seen in active lesions
targeting T cells (cyclosporine, UV light) improves psoriasis |
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Term
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Definition
T cells in psoriasis are polarized to the Th-17 phenotype
Th-17 cells produce cytokines that drive the development of psoriasis plaques:
IL-17 --> T cell influx
IL-22 --> acanthosis |
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Term
| polarization of Tcells to Th-17 |
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Definition
| naive T cells differentiate to Th-17 in the presence of IL-6, TGF-beta, and IL-23 |
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Term
| paradigm of immune involvement in psoriasis |
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Definition
| some effect of Th-1 activity, but Th-17 is the major player |
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Term
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Definition
| Th-17 cells are stimulated by IL-23 derived from dendritic cells |
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Term
| key cytokines in psoriasis |
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Definition
IL-23 (from dendritic cells)
IL-17, IL-23 (from Th-17 cells)
INF-gamma (from IL-1)
TNF-alpha |
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Term
| targeting TNF-alpha in psoriasis treatment |
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Definition
therapies that bind to an neutralize the pro-inflammatory effects of TNF-a
Etanercept
Infliximab
Adalimumab |
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Term
| targeting IL-23 in psoriasis |
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Definition
IL-23 stimulates Th-17 cells
*ustekinumab* specifically targets IL-23
-fully human antibody that neutralizes IL-23, dampens activity of Th-17 cells |
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Term
| non-targeted psoriasis therapies |
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Definition
topicals used when <10% skin surface (topical steroids, Vit D analogues)
10-20% surface involvements:
UV phototherapy
retinoids
methotrexate
cyclosporine |
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