Psoriasis Flashcards
what is psoriasis?
Chronic, genetically determined, immune-mediated, inflammatory skin condition, usually characterized by typical well defined, scaly, plaques.
It can also involve nails, hair and joints
what does psoriasis look like?
Red scaly plaques
Often symmetrical distribution
Chronic plaque Flexural Acute Guttate Scalp Palmoplantar Nail Pustular Erythrodermic
what are the causes of psoriasis?
Overactivity of the immune system
Excessive production of TH1 Cytokines inc TNF-alpha
Vascular proliferation (erythema), increased cell turnover (plaques and scaling)
Genetics Environmental Infection Strep, Candida Drugs Lithium, Beta-blockers, NSAIDS, Steroid withdrawal Trauma – Koebner phenomenon (spread with trauma) Sunlight
what is the pathogenesis of psoriasis?
Epidermal infiltration by activated T cells
genetics- family history
precipitants-trauma
infection
drugs
what is the histology of psoriasis?
Hyperkeratosis (thickening of stratum corneum) with parakeratosis (keratinocytes with nuclei in stratum corneum)
Neutrophils in stratum corneum (munro’s microabcesses)
Hypogranulosis: no granular layer (needed for barrier function)
Psoriasiform hyperplasia: Acanthosis (thickening of squamous cell layer) with elongated rete ridges
Dilated dermal capillaries
Perivascular lymphohistiocytic infiltrate; T cell infiltration
how common is chronic plaque psoriasis?
90% of psoriasis cases
how is chronic plaque psoriasis managed?
topical treatments
how do people get gluttate psoriasis
common post viral
what is the psoriasis of the palms and soles of feet?
Palmo-plantar Psoriasis
what is the differential diagnosis of scalp psoriasis?
Seborhoeic dermatitis
what are the pathognomonic features of nail psoriasis?
pitting
onhycholysis
what is the diagnosis of shiny pink to red sharply demarcated plaque with no scaling
Flexural / Inverse Psoriasis
50 year old lady presents with an acute onset of generalised red, tender patches. On closer inspection of the patches multiple yellow pustules are seen
what would this be?
Pustular Psoriasis
what would be the diagnosis of “red man syndrome”
Erythrodermic psoriasis
name some differential diagnosis’s?
Seborrhoeic dermatitis
(Esp Scalp, face)
Lichen planus
(Check forearm, oral mucosa)
Mycosis fungoides
(older Pt, Sudden onset of plaques or treatment resistant plaques – Think of biopsy)
