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
What is erythrodermic psoriasis?
Symptoms?
Who gets it?
Precipitated by?
A potentially life-threatening medical emergency
Diffuse, widespread severe psoriasis that affects >90% of the body’s SA
Lesions may feel warm
May be associated with systemic illness
Can develop gradually from chronic plaque psoriasis or abruptly, even in people with mild psoriasis
Can be precipitated by systemic infections, irritants e.g. coal tar, phototherapy or sudden withdrawal of corticosteroids
Most common form of psoriasis?
Chronic plaque psoriasis
Presentation of chronic plaque psoriasis?
Erythematous plaques covered with a silvery-white scale (less commonly waxy yellow or orange-brown). Plaques 1-10cm
If the scale is removed then a red membrane with pinpoint bleeding points may be seen (Auspitz’s sign)
Typically on the extensor surfaces. Also common scalp, behind ears, trunk, buttocks, periumbilical area
Lesions are typically symmetrical and can coalesce to form larger lesions
A clear delineation between normal and affected skin
What % of those with psoriasis will experience scalp psoriasis?
75-90%
Scalp psoriasis:
What type?
Where does it affect?
Typically chronic plaque psoriasis
Whole scalp can be affected or individual plaques
Plaques may be very thick., particuarly in the occipital region
May be associated with areas of non-scarring Alopecia, pityriasis amiantacea (scale extending up the hair shaft), Erythrodermic psoriasis, itchiness of scalp
How does flexural psorasis typically present?
Typically affects areas such as groin, genital area, axillae, inframammary folds, abdominal folds, sacral and gluteal cleft
Itchy
Lesions of chronic plaque psorasis which are well0defined but little/no scaling due to friction and occlusion at these sites - lesions are red, skin smooth and glazed in appearance
Who is at increased risk of being affected by flexural psoriasis I?
Elderly
Immobile
Overweight or obese
FHx
HIV or AIDs
Smokers
How does gutatte psorasis present?
Acute onset over days…
Small, scattered, rough or oval scaly papules which may be pink or red. 2mm-1cm in diameter
Multiple lesions may occur all over the body over a period of 1-7 days, particularly on trunk and proximal limbs
Lesions may occur on face, ears, scalp and rarely soles of feet
Typical age of onset for gutatte psorasis?
Children, teenagers and adults <30
What typically causes first presentation guttate psorasis?
After streptococcal URTI 2-4 weeks prior
After an acute exacerbation of plaque psoriasis
Following Covid—19
Which nails does nail psorasis more commonly affect?
Fingernails - 50%
Toenails - 35%
Nail psoriasis presentation?
Nail pitting - most common
Discolouration - orange/yellow discolouration of nail bed ‘oil drop sugn’
Subungal hyperkeratosis
Onycholysis
Complete nail dystrophy
What is subungal hyperkeratosis?
hyperproliferation of the nail bed, with accumulation of keratinocytes under the nail.
(Accumulation of chalky substance/scales under nail plate)
What is onycholysis?
detachment of the nail from the nail bed, which may allow bacteria and fungi to enter and cause infection.
Management of suspected pustular psorasis?
Immediate same-day specialist dermatology assessment if generalised
If localised also refer but urgency should depend on clinical judgement
Management of suspected erythrodermic psorasis?
Arrange for immediate same-day specialist dermatology assessment
Management of chronic plaque psoariais of trunk and limbs in primary care?
General - smoking cessation, low alcohol, weight loss if overweight
Assess for psychological distress
Regular emollients to help reduce scale loss and reduce pruritus
Potent corticosteroids + vitamin D analogue - apply one in am and one in pm for up to 4 weeks the review
If no improvement at 8 weeks over vitamin D analogues twice daily
If no improvement after 8-12 weeks then offer potent corticosteroids twice daily for up to 4 weeks, or a coal tar preparation OD or TD
If still no improvement short-acting dithranol can be used
Then refer to secondary care!
Management of chronic plaque psoariais of trunk and limbs in secondary care?
Phototherapy - narrowband UVB 3 times a week, or photochemotherapy (psoralen + UVA)
Systemic therapy - oral methotrexate. Others: Ciclosporin, systemic retinoids, biological agents ur ustekinumab
Management of scalp psoriasis?
General lifestyle advice - stop smoking, weight loss if overweight and sensible alcohol amounts
Assess for psychological distress
Potent topical corticosteroid OD for 4 weeks
If not tolerated then vit D prepareation OD
A coal tar shampoo can be used (not alone if severe!!)
If no improvement after 4 weeks then use a different formulation of the corticosteroid e.g. shampoo, and/or a topical agent to remove the adherent scale before application of the steroid e.g. oils, emollients, salicyclic acid-containing agents
Managing facial, flexural and genital psorasis?
Emollient to reduce scale and relieve itch
Short-term mild or moderately potential topical corticosteroids OD or TD for up to 2 weeks
Why should you not use topical steroids on the scalp, face and flexure for more than 2 weeks a month?
As these areas are particuarly prone to steroid atrophy
How much potent corticosteroid would you have to use to see systemic SE?
Used on large area i.e. >10% of body SA
How long do NICE recommend leaving between courses of topical steroids?
4 weeks
How long do NICE recommend is the max amount of time you should use topical potent or very potent corticosteroids for?
Potent 8 weeks
Very potent 8 weeks
Examples of vitamin D analogues?
Calcipotriol - dovonex
Calcitriol
Tacalcitol
How do vitamin D analogues work for psoriasis?
They work by decreasing cell division and differentiation which reduces epidermal proliferation
They tend to reduce the scale and thickness of plaques but not the erythema
Pregnancy and vitamin D analogues
Avoid!
How does dithranol work for Tx of chronic plaque psoriasis?
Adverse efefcts
It inhibits DNA synthesis
(Wash it off after 30 mins)
Burning and staining
How does coal tar work for chronic plaque psoriasis management?
MOA not fully understood - probably inhibits DNA synthesis
Prognosis of guttate psoriasis?
Most cases will resolve spontaneously within 2-3 months
Management of guttate psoriasis
Assess for psychological distress
If lesions are >10% of body SA then urgent referral to dermatologist for consideration of phototherapy
If lesions are not widespread options are:
- no treatment
- emollients to reduce scale and itch
- potent topical corticosteroid + topical vitamin D prepareation one in am and one in pm.
- UVB phototherapy can be used
Tonsillectomy may be necessary with recurrent episodes - ? Reduces strep infections
Managing nail psoriasis?
Advise them that improvementsa in nail psoriasis may lag behind improvements in skin and joint disease if affected as nail psoriasis is generally refractory to topical Tx
Advise them to keep nails short to avoid exacerbating onycholysis and reduce accumulation of material under the nail
Avoid manicure of the cuticle to prevent Paronychia
Nail varnish to disguise pitting (avoid abrasive acetone-based nail varnish removers!)
If severe then consider an alternative diagnosis!!
Biologics used in management of psoriasis?
Infliximab
Etanercept
Adalimumab
