Psoriasis Flashcards
What is psoriasis?
Occurs due to autoimmune disease causing hyperproliferation of the epidermidis.
What differentials should you consider when suspecting psoriasis?
Important to rule out eczema e.g. history of atopy, seborrheic dermatitis, mycosis fungoides and tinea.
What the main risk factors for psoriasis?
Family history
Strep infection – specifically for guttate psoriasis
What triggers psoriatic flares?
Stress Infections especially strep Skin trauma Drugs – lithium, beta blockers, NSAIDs, ACE inhibitors, infliximab, Beta-blockers and anti-malarial Alcohol Obesity Smoking Climate (note sun usually improves symptoms) Withdrawal of steroids (be very careful)
How does psoriasis present?
Relapsing remitting course
Scaly erythematous plaques
Itchy and irritated
Majority are affected before the age of 46
Nails changes – pitting, onycholysis, thickening and subungual hyperkeratosis
Around 7% develop psoriatic arthritis
What complications can occur from psoriasis?
Complications – MACE major adverse cardiac events – MI, stroke, cardiac associated death, psoriatic arthropathy, IBD (uncertain) and malignancy – specific lymphoma.
What are the different types of arthritis associated with psoriasis?
Around 7% develop psoriatic arthritis which has 5 types: monoarthritis or oliomonoarthritis, psoriatic spondylitis, asymmetrical polyarthritis, arthritis mutilans (destructive) and Rheumatoid -like polyarthritis.
Name the 4 types of psoriasis
Chronic Plaque Psoriasis
Flexural Psoriasis
Guttate Psoriasis
Pustular Psoriasis
Describe chronic plaque psoriasis
Chronic Plaque Psoriasis – symmetrical well-defined erythematous plaques with a silvery scale on extensor aspects of the elbows, knees, scalp and sacrum
Describe flexural psoriasis
Flexural Psoriasis – plaques in moist flexure areas such as axillae, groin, sub mammary areas and umbilicus. These are less scaly, and the skin is typically smooth and can be misdiagnosed as fungal infections
Describe guttate psoriasis
Guttate Psoriasis – large number of small tear drop plaques on the trunk and limbs and seen in the young more commonly, usually after a streptococcal throat infection
Describe pustular psoriasis
Pustular Psoriasis – palmoplantar psoriasis – yellow-brown pustules within plaques affecting the palms and soles (women most often)
What is the purpose of emollients in psoriasis and what base should they be supplied in?
For all topical treatments select a base the patient prefers from cream, ointment, foam, gel or lotion. Emollients reduce scale and relieve irritation
What general advice should be given to all psoriasis patients?
Not infective, not treatable but we can control symptoms
Stop smoking and drink alcohol within normal limits
Weight loss
What are the 1st, 2nd and 3rd line management steps in plaque and scalp psoriasis?
First line
Topical vitamin D preparation e.g. calcipotriol, calcitriol and tacalcitol etc. – once a day and a POTENT topical corticosteroid – once a day. Apply vitamin D and steroid separately at opposite times of the day
Second line – If no improvement after 8 weeks, increase topical Vit D to twice daily
Third line – If no improvement after 8-12 weeks, increase the potent corticosteroid to twice daily for 4 weeks or a coal tar (probably inhibits DNA synthesis) preparation once or twice daily. Short acting dithranol is also an option – inhibits DNA synthesis, wash off after 30 minutes. SE burning and staining.
What are the rules for prescribing steroids in psoriasis?
Give treatment break of 4 weeks for the steroid before starting a new course and continue the vitamin D in this time. Do not use potent steroids for longer than 8 weeks or very potent steroids for longer than 4 weeks at a time.
What important side effects of topical steroids should be considered in psoriasis?
SE – skin atrophy, striae and rebound symptoms.
How does vitamin D work in psoriasis and when shouldn’t they be used?
These work by reducing cell division and differentiation and adverse effects are uncommon. Can be used long term and unlike coal tar and dithranol they do not smell or stain. They reduce scale and thickness of plaques but not the erythema. Do NOT use in pregnancy.
How is management of flexural (+genital and facial) psoriasis different from plaque?
Strong topical steroid and emollients as per chronic plaque but only used mild-moderate potency steroids on face, flexures, and genitals. Review after 4 weeks.
How is guttate psoriasis managed?
Usually resolves within 3-4 months and no evidence to support use of antibiotics
Topical agents as usual – steroids and Vitamin D
UVB phototherapy
Tonsillectomy maybe necessary with recurrent episodes
When should a psoriasis patient be referred to secondary care?
Diagnosis unclear, psoriasis is severe
Refer for specialist If > 10% of body affected
What role does phototherapy play in psoriasis management?
Consider phototherapy or systemic therapy if >10% of body is affected
Narrowband UVB – most suited to plaque and guttate psoriasis given 3 times a week
PUVA (Psoralen + UVA) – plaque or localised pustular psoriasis but note increased risk of SSC
Describe the 3 common systemic non-biologic drugs given in psoriasis and their SE?
Methotrexate is 1st line in secondary care – most useful in old patients and those with arthropathy. SE include mouth ulcers, infertility, lung fibrosis,
Ciclosporin – affective but SE usually intolerable – Gingival hyperplasia, hair growth, hypertension, hyperkalaemia and hyperglycaemia
Acitretin – oral retinoid, SE teratogenic, dry skin and mucosae, raised lipids, glucose and
LFTs.
What monitoring must take place in patient taking Acetretin?
Must check lipids, glucose and LFTs before commencing and then check every 2 weeks for 2 months then every 12 weeks. Avoid pregnancy until >2 years after last dose.
What biologic therapies are used in severe psoriasis?
Inhibit T cell activation and function or neutralise cytokines. Consider infliximab, adalimumab and etanercept.
What is erythroderma?
Erythroderma is when 90% of the skin is involved in a red rash of any kind.
What is the most common cause of erythroderma?
1/3 of cases of erythroderma are caused by generalised erythrodermic psoriasis
How does generalised erythrodermic psoriasis develop?
Develops gradually from chronic plaque psoriasis or appear abruptly even in people with mild psoriasis.
What can trigger generalised erythrodermic psoriasis?
Can be triggered by rapid withdrawal of steroids as well as coal tar, ciclosporin and phototherapy.
What complications can occur from erythroderma?
Dehydration Heart failure Infection Hypothermia Oedema
How is generalised erythrodermic psoriasis managed?
Medical emergency – admit immediately
IV fluids and temperature regulation
Bland emollients and cooling wet dressings
Low dose methotrexate, ciclosporin or acitretin
Avoid oral steroids
What else can cause erythroderma?
Eczema
Drugs e.g. sulphonamides, allopurinol, carbamazepine and gold, also withdrawal of steroids
Lymphomas, leukaemias
Idiopathic
What is generalised pustular psoriasis?
Rapidly developing widespread erythema followed by the eruption of white sterile non follicular pustules which coalesce to form large lakes of pus. Usually occurs in people with existing or previous chronic plaque psoriasis but can also occur in people without a history of psoriasis.
What triggers generalised pustular psoriasis?
Can be triggered by sudden withdrawal of steroids or drugs such as lithium, aspirin, iodine, and some beta blockers. It is also associated with pregnancy.
How does generalised pustular psoriasis progress?
Remission can occur within days or weeks
Sometimes erythroderma may develop
Relapse are common
Complications are similar to those of erythroderma
How is generalised pustular psoriasis managed?
Admit to hospital
Prevent further fluid loss and maintain temperature
Affected areas treated with bland topical compresses and emollients
Low potency topical steroid creams
Antibiotics for any secondary infections
