Psoriasis Flashcards Preview

OS 212 DERMATOLOGY > Psoriasis > Flashcards

Flashcards in Psoriasis Deck (36):
1

Chronic, relapsing, immune related, inflammatory (presence of neutrophils) disease

Psoriasis

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Onset of Psoriasis

usually at 15-30

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Layers of the skin affected

Inflmmatory cells
thinner stratum granulosum
Hypercellular stratum spinosum

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Psoriatic skin

increased production of cells, resulting in decreased regeneration time and thickening of epidermis

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Classic presentation of psoriasis

circumscribed, erythematous plaques covered with thick silvery white scales which may be associated with itching or burning

6

Normal skin

Proliferative Cell population: 27,000 cells/cumm

Cell cycle Duration: 311 hours (13 days)

Epidermal Transit time: 28 days

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Psoriatic skin

Proliferative cell proliferation: 52,000 cells/cumm

cell cycle duration: 26 hours (1.5 days)

Epidermal transit time: 3-4 days

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Etiology of Psoriasis

Manifestation of Genetic and environmental factors

Chromosome 6

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genetic factors of Psoriasis

Multiple genetic oci
HLA: Cw6, B13, B27

Non-HLA: PSORS1-10 cytokine receptor genes

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Triggers of Psoriasis

STRESS
TRAUMA
INFECTION
DRUGS (Anti-malarials, lithum, beta-blockers)

cold weather
Sunlight
Obesity
Smoking

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Type 1 Psoriasis:

(+) family history, and is usually associated with HLA-Cw6

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Pathophysiology of Psoriasis

Autoimmune disease

T-cell mediated (predoinantly Th1 and Th17)

13

Dendritic Cell and T cell activation and the release of cytokines leads to:

Keratinocyte Proliferation with altered differentiation

Plaque formation

Further release of chemokines and cytokines

Leukocyte recruitment

Angiogenesis

14

Autoimmune T-cell mediated reaction with

Over expression of pro inflammatory type 1 cytokines

Inflammation

Vessel dilation and new vessel formation

Lymphocyte and neutrophilic infiltration in the dermis and epidermis

Accelerated epidermopoiesis

15

RED

Angiogenesis and vasodilation

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THICK

keratinocyte proliferation

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SCALY

Poor keratinocyte differentiation

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Histological Findings

Hyperkeratosis
Parakeratosis
Dilated capillaries/blood vessels
Neutrophils
Stratum spinosum

19

Due to dermal angiogenesis

Bleeding upon removal of scales atop a thinned suprapapillary plate

due to proximity of surface of dilated tortuous blood vessels found on the tips of dermal papillae

Pain on grasping with thumb

AUSPITZ SIGN

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When scratched, skin produces new lesion

Not exclusive to psoriasis; also present in lichenus planus, verruca vulgaris, vitiligo

Traumatic induction of psoriasis on non lesional skin

Isomorphic response of skin on lines of trauma

Koebner Phenomenon

21

Most common morphology of Psoriasis

Extensor surfaces

Plaque

-psoriasis vulgaris

22

Smaller drop like plaques with finer scales

Commonly associated with prior streptococcal infection in children and adolescents

Guttate

23

There are no bacteria and therefore not contagious. Contains neutrophilic infiltrates

Sterile Pustules

-will not clear with antibiotics

24

Localized to the digits (acral) portion

may destroyed nailbed

Acrodermatitis continua

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Generalized acute pustular psoriasis

Abrupt onset associated with fever, chils and malaise

Conglomeration of pustuliness

von Zumbusch

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Generalized pustular psoriasis of pregnancy

Impetigo herpetiformis

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End result of a lot of diseases

Scaling is not evident if acute

generalized erythema with or without scaling

Erythroderma or Exfoliative Dermatitis

28

Can present with oatmeal-like scales with marked erythema

Initial site involvd in most patients

May extend to anterior or posterior hairline, retroauricular

Scaling not as prominent as in children

Scalp Psoriasis

29

Less scaly because the areas are moist

Usual Presentation of infantile psoriasis

Along body folds

Flexures, Intertriginous, or inverse

30

Ocassionally occurs alone without other skin sites involved; mistaken as onychomycosis

May be associated with P. arthritis of the DIP joint in the same digit

Onycholysis and pitting rarely occur together

Nail Psoriasis

31

Separation of the nail plate from the nail bed

Onycholysis

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Dilated blood vessels and erythema of nail bed; signifies beginning parakeratosis

oil spots

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Dilated blood vessels and erythema of nail bed

Piting

34

Accumulation of keratin under the nail; opaque appearance

Subungual hyperkeratosis

35

Sausage digits

Dactylitis

36

Inflammation commonly on achilles tendon bony attachment

Enthesitis