PSORIASIS Flashcards
Epidemiology of psoriasis?
Common - 1-3% of world’s and Uks population
Unconommon in children
Peaks of incidence = 20-30 and 50-60
Men and women are equally affected
White people are more likely to develop the condition
Family history in up to 50% of people with psoriasis
Different forms of psoriasis? How common are each type?
Chronic plaque psoriasis “psoriasis vulgaris” 80%
Localised pustular psoriasis of palms and soles - second most common
Flexural psoriasis - 7%
Guttate psoriasis - 3%
Erythrodermic psoriasis 2%
Generalised pustular psoriasis 1%
Nail psoriasis 50%
What is erythrodermic psoriasis?
A rare form of psoriasis that affects nearly all the skin on the body, causing an intense itching or burning
Can come of suddenly
Can be a medical emergency as body may lose proteins and fluid causing dehydration, HF, hypothermia and malnutrition
Who is nail psoriasis most common in?
Those with psoriatic arthritis - up to 90% will have nail involvement
Trigger factors for psoriasis?
Streptococcal infections
Drugs
UV light exposure
Trauma
Hormonal changes e.g. puberty post-partum, menopause
Psychological stress
Smoking
Alcohol
Obesity
Which psoriasis is streptococcal URTI strongly associated with?
Guttate psoriasis
Which drugs can exacerbate psoriasis?
Lithium
Antimalarial drugs
Beta blockers
NSAIDs
ACEi
Trazodone
Terfenadine
Antibiotics - tetracycline and penicillin
Why is it important to not withdraw steroids suddenly in a patient with psoriasis?
It can lead to a severe rebound phenomenon which can even evolve into generalised pustular psoriasis or erythrodermic psoriasis rarely
What is the Koebner phenomenon?
When trauma (e.g. piercings, tattoos, burns, surgery, scratching) to previously uninvolved skin can be followed by the development of psoriasis 7-14 days later
May affect up to 20% of those with psoriasis
Psoriasis in pregnancy?
It typically will improve
In up to 20% of women it will worsen
Which psoriasis is most strongly linked to smoking?
Localised pustular psoriasis
Almost exclusively exists in people who smoke
What conditions are associated with psoriasis?
Psoriatic arthritis
Metabolic syndrome
Ischaemic heart disease
IBD
Anxiety and depression
VTE
Non-melanoma skin cancer
Lymphoma
Ophthalmological conditions
Coeliac disease - plaque psoriasis
What % of those with psoriasis will get psoriatic arthritis?
Up to 30%
When will psoriatic arthritis typically occur in respect to psoriasis?
Skin psoriasis will typically develop 5-10 years before psoriatic arthritis
Complications of psoriasis?
Psychological - anxiety and depression
Relationship diffiuclties, negative body image, low self esteem etc
Social - Limitation of activities e.g. swimming and jobs that require skin exposure
Erythrodermic psoriasis which has its own complications
Increased incidence of metabolic syndrome
Increased incidence of CVD
Increased incidence of VTE
Pregnancy complications - miscarriages, preterm, LBW - plaque psoriasis and generalised pustular psoriasis
Prognosis of plaque psoriasis?
Chronic condition
Spontaneous remission in up to 25% of people
Prognosis of guttate psoriasis?
Self-limiting and resolves within 3-4 months of onset
About 1/3rd of people develop classic plaque disease
Aetiology of psoriasis?
multifactorial and not yet fully understood
genetic: associated HLA-B13, -B17, and -Cw6. Strong concordance (70%) in identical twins
immunological: abnormal T cell activity stimulates keratinocyte proliferation. There is increasing evidence this may be mediated by a novel group of T helper cells producing IL-17, designated Th17.
Environmental: it is recognised that psoriasis may be worsened (e.g. Skin trauma, stress), triggered (e.g. Streptococcal infection) or improved (e.g. Sunlight) by environmental factors
Pathogenesis of Psoriasis?
Epidermal hyperproliferation — cells multiplying too quickly.
Abnormal keratinocyte differentiation — cells not maturing normally.
Lymphocyte inflammatory infiltrate — the presence of cells which cause inflammation.
What is generalised pustular psoriasis?
A potentially life-threatening medical emergency
Rapidly developing widespread erythema followed by eruption of white, sterile non-follicular pustules which coalesce to form large lakes of pus
Associated with systemic illness
Usually presents in people with existing or previous chronic plaque psoriasis but can also occur in people with a history of psoriasis
What is localised pustular psoriasis?
Lesions on palms and soles
Yellow-brown pustules within established psoriasis plaques, or redness scaling and pustules at the tips of fingers and toes