Psoriasis Flashcards
Presentation of psoriasis
Sharpley demarcated erythematous plaque with micaceous scale (red scaley patches) Numerous small, widely disseminated papules and plaques Erythroderma (>80% BSA) Pustules Nails - onycholysis - pitting - oil spots Scalp Koehner phenomenon Woronoffs ring
Who gets psoriasis?
M = F
20 - 30yrs and 50 - 60 yrs
75% before 40 years
What % develops psoriatic arthritis?
5 - 30%
Types of psoriasis
Chronic plaque psoriasis Guttate psoriasis Palmo-plantar psoriasis / pustulosis Scalp psoriasis Nail psoriasis Flexural / inverse psoriasis Pustular psoriasis Erythrodermic psoriasis
What can guttate psoriasis be trigged by?
Viral or bacterial infections (commonly strep)
Who gets guttate psoriasis?
Children
Adolescents
What may happen as a consequence of guttate psoriasis?
May resolve or may trigger chronic psoriasis in susceptible individuals
What is palmo plantar psoriasis associated with?
Smoking
Sterile inflammatory bone lesions
Presentation of scalp psoriasis
Severe dandruff
Spreading onto face
Hyperkeratotic plaques on scalp, extending just beyond hairline onto neck and forehead
Nail pitting
What can scalp psoriasis lead to on the affected areas?
Alopecia
What is a key feature of flexural/inverse psoriasis?
No/less scale
What can trigger flexural/inverse psoriasis?
Localised dermatophyte, candida or bacterial infection
Differential diagnosis of flexural/inverse psoriasis
Localised dermatophyte infection
Candida infection
Bacterial infection
Presentation of pustular psoriasis
Sterile pustules
Systemic symptoms
Causes of pustular psoriasis
Pregnancy
Rapid taper/stop steroids
Hypocalcaemia
Infection
What does pustular psoriasis overlap with?
AGEP (pustular drug eruption)
What is erythrodermic psoriasis?
History of psoriasis - flare up
> 80% of body surface erythematous with fine scale
What is another name for erythrodermic psoriasis?
Red man syndrome
Investigations for psoriasis
Clinical
Skin biopsy if atypical
Differential diagnosis of psoriasis
Seborrheic dermatitis Lichen planus Mycosis fungoides Bowens disease Drug eruption Infection Secondary syphilis Contact dermatitis Extramammary pagets
What % of psoriasis have FH?
35-90%
What genetic mutation can be found in psoriasis?
HLA-Cw6 (chromosome 6)
Causes of psoriasis
Genetic Infection Drug Trauma Sunlight
Pathology of psoriasis
T cells (epidermal CD8, dermal CD4 + CD8)
Stressed keratinocytes
Activation of dermal dendritic cells by interleukins and TNF alpha
dDCs -> lymph nodes, present uncertain antigen to naïve T cells
Differentiation into T helper 1, 17 and 22 -> psoriasis -> plaque formation
Interleukins and TNF alpha amplify the inflammatory cascade, stimulate keratinocyte proliferation
VEGF -> angiogenesis
Neutrophils in acute, active, pustular disease
Cell cycle reduced
What is the cell cycle change in psoriasis?
Reduced from 28 days to 3-5
Histology of psoriasis
Hyperkeratosis (thickening of strateum corneum)
Neutrophils in the strateum corneum
Psoriasiform hyperplasia; acanthosis (thickening of squamous cell layer) with elongated rete ridges
Dilated dermal capillaries
T cell infiltration
Treatment of psoriasis
Regular Emollients Soap substitutes 1. Vitamin D3 analogues (inhibit epidermal proliferation) + potent corticosterioid once daily 1st line Coal tar creams / crude coal tar Topical steroid (flexures, genitalia) Salicylic acid (keratolytic) Dithranol UVB phototherapy (guttate) Retinoids - Acitretin Methotrexate Ciclosporin Biologic therapies (Anti-TNF etc)
Treatment of erythrodermic psoriasis
Admit Fluid balance Bloods/IV access Thick greasy ointment emollients Possible systemic or biologic treatment
How is psoriasis progress monitored?
Psoriasis Area Severity Index (PASI)
Dermatology Life Quality Index (DLQI)
What does PASI look at?
Surface area
Plaque colour
Thickness
Scale
What does DLQI look at?
QOL in last 1 week
What prognostic outcomes is psoriasis related to?
CVS disease Smoking Metabolic syndrome Alcohol Depression Suicide Melanoma and non melanoma skin cancers Harmful drug and light therapies
Patients with psoriasis are at increased risk of what?
Arthritis
Cardiovascular disease
Complications of psoriasis
Psoriatic arthropathy (10%)
Increased incidence of metabolic syndrome
Increased incidence of cardiovascular disease
Increased incidence of VTE
Psychological distress
Exacerbating factors of psoriasis
Trauma Alcohol Drugs - beta blockers - lithium - antimalarials - NSAIDs - ACE Is - infliximab Withdrawal of systemic steroids
What drug can make psoriasis worse?
NSAIDs
The 5Ps of lichen planus
Polygonal Pruritic Planar (flat-topped) Papular lesions Purple
