Papulosquamous Disorders Flashcards
What is psoriasis?
A papulosquamous skin disorder Chronic Non infectious Inflammatory autoimmune Relapsing and remitting Male=female
Well defined
Salmon pink plaques
Adherent silvery scales
Auspitz’s sign
What is the pathogenesis of psoriasis?
T cell mediated autoimmune response to keratinocytes
Hyper proliferation of keratinocytes
Accumulation of inflammatory cells
Shortened epidermal turnover time <10days
What are the precipitating factors of psoriasis?
Genetic, paternal imprint,
HLA CW6
Trauma (kobner phenomenon)
Infection (strep staph hiv)
Hormones (better in pregnancy, worse HYPOparathyoidism)
Sunlight 90%
Drugs (beta blockers, lithium, antimalarials, captopril)
Cigarette and alcohol
Emotion
What is the pathology of psoriasis?
Nucleated keratinocytes in corneum
Thick epidermis
Epidermal neutrophil infiltration
Dilated dermal capillary loops
Dermal T cell infiltration
What are the presentations of psoriasis?
Common
- chronic plaque
- guttate (children, adolescent)
- scalp
- nails (pitting, onycholysis, subungual hyperkeratosis)
- flexural (women . Elderly)
- palm and sole pustular
Less common
- pustular psoriasis
- erythrodermic
- arthritis mutilans
- enthesitis
What are the DDx for psoriasis?
Discoid eczema (itchy)
Seborrhoeic eczema
Pityriasis rosea
Secondary syphilis
Cutaneous T cell lymphoma
Tinea unguium
What are the treatments for psoriasis?
Non pharmacologic
-education and counseling
Pharmacologic
Local/topical
- vitamin d analogues
- local retinoids
- topical corticosteroids
- dithranol (anthralin)
- coal tar
- salicylic acid
- topical immunomodulators calcineurin
UVB Radiation
Systemic (if affecting >20% BSA)
- photochemotherapy psoralen+UVA
- retinoids
- methotrexate
- ciclosporin
Biological
- block T cell trafficking
- block cytokine
- block T cell activation
Combined
- Ingram regimen
- goeckerman regimen
What is pityriasis rosea?
Papulosquamous skin disorder By reactivation of HHV 6,7 Not contagious Herald plaques then fir clusters Round erythematous scaly plaques
What are the DDx for pityriasis rosea?
Guttate psoriasis Tinea corporis Secondary syphilis Captopril eruption Pityriasis versicolor
What is lichen planus?
Violaceous Itchy Flat topped papules On volar aspect of limbs Wickham’s striae Oral and genital striae Kobner phenomena
What are the causes for exfoliating erythroderma?
Psoriasis Eczema Lymphoma Scabies Drug eruptions
