Skin OTC - Psoriasis Flashcards
What are the clinical features of psoriasis?
Red, scaly and sharply dermacated plaque.
Can be any size and affect any part of the body.
Most common sites: extensors elbows and knees surface, sacrum and scalp.
Hands/feet
Scale easily scraped off revealing tiny bleeding points
Pruritis
Relapse and remitting conditions
Impacts QofL with psychological/social disability.
What are the precipitating factors of psoriasis?
Trauma
Infection
Hormones
Sunlight
Medications e.g. BB, Lithium, Antimalarials
Alcohol
Smoking
Profound psychological stress
What are the main features of chronic plaque psoriasis?
Psoriasis plaques formed by skin cell build up.
Red, itchy, sore, white/silvery scales.
Well demarcated
Flexural psoriasis (little to no scale due to friction) e.g. sub mammary, axillary, ano-genital folds.
Cracks/bleeds
What are the main features of guttate psoriasis?
Affects children/ young adults.
Can occur as psoriasis or exacerbation of chronic plaque psoriasis.
Commonly follows a streptococcocal throat infection.
Self-limiting
Widespread small, pink macules becomes scalp but clears within a few months.
What are the main features of erythrodermic psoriasis?
Generalised skin redness involving all or nearly all the skin’s surface.
Occurs when it’s progresssively worsening chronic plaque psoriasis, precipitated by infection, tar, drugs or CS withdrawal.
Erythoderma = dermatological emergency!
What are the main features of generalised pustular psoriasis?
Very rare generalised eruptive form of psoriasis accompanied by fever and toxicity.
Acute erythema is seen with a rapid spread of multiple sterile pustules over the body, concentrated in flexures, genital regions and finger tips.
Medical emergency = A+E referral
What are the main features of psoriatic arthritis?
Commonly affects hands/feet.
Swollen, inflamed, painful joints.
Rheumatologist referral.
NSAIDs, Steroids, DMARDs/biologics may be required.
What are the main features of nail psoriasis?
Can occur with all types of psoriasis.
Nails pitting, discolouration (oil spots, salmon patches), nail bed hyperproliferation, oncholysis
What tools are used for assessing the condition of psoriasis? (2)
PASI (Psoriasis area severity index)
PGA (Physician Global assessment)
What are the treatment options for psoriasis?
Emollients: Soften plaques, reduces itching/redness, improve topical CS absorption. Anti-proliferative effect.
1st line: Topical CS, Vitamin D analogues, Dithranol, Tar prep.
2nd line: Phototherapies, systemic non-biologic therapies (MTX, Ciclosporin, Acitretin)
3rd line: Systemic biologic therapies (Adalimumab, Etanercept, Infliximab, Ustekinumab)
Salicylic acid: Used to remove scales before potent steroid application if initial tx for 4 weeks isn’t satisfied.
Explain the main features of topical therapy.
Emollients
CS: Acutely inflamed plaques and on face/flexures. Ineffective on chronic scaly plaques, risk of rebound flares.
BAD guidelines:
- Don’t use regularly for > 4 weeks without review, px may need follow up appointment.
- Don’t use potent steroids regularly for > 7 days.
- Review every 3 months.
- No > 100g of a moderately potent or higher potency prep should be applied per month.
- Attempt to rotate topical steroids with alternative non-steroid prep.
Explain the main features of vitamin D analogues.
E.g. calcipotriol, tacalcitol, calcitriol
Useful in mild-moderate chronic plaque psoriasis can clear psoriasis in 6-8 weeks.
MOA: Inhitis keratinocyte differentiation and proliferation, anti-inflammatory activity.
Don’t smell/stain like older tx (tar/dithranol)
May be as effective as potent steroids but with longer duration of remission after tx as stopped.
Can cause skin irritation resulting in transient increased redness/dryness and stinging/burning (Calcipotriol not used on face/flexures, calcitriol ok, less irritant)
Adequate quantities used - 0.5g (fingertip unit) for 10cm2 skin (1 medium sized adult palm)
Apply thickly
Max weekly doe to avoid hypercalcaemia:
- Calcipotriol 100g
- Calcitriol 210g
- Tacalcitol 70g
Explain the main features of Tazarotene.
Active retinoids (Vitamin A)
MOA: Normalises ketinocyte differentiation, antiproliferative and antiinflammatory effects.
Moderately effective.
Limited use by skin irritation and increased photosensitivity.
Teratogenic
Explain the main features of coal tar.
MOA: ketatolytic with anti-inflammatory and antiproliferative effects.
Stains clothes
Smells unpleasant
Less effective than vitamin D
UVB combination
Explain the main features of Dithranol.
Skin irritant causing inflammation and blistering.
Causes temporary skin staining and permanent clothes staining and bathroom fittings.
Lassar’s paste used to prevent Dithranol spreading to uninvolved skin areas.
Response to rx around 3 weeks.
Unsuitable for multiple small plaques, flexural psoriasis due to irritant nature.
Conc. is gradually increased according to px’s response.
Short-contact Dithranol Tx (SCDT): Application of up to 8% between 15-30 mins with or without UVB. Suitable for home use.
Explain the main features of phototherapy.
Tx given 3x per week until psoriasis clears.
C/I in px taking photosensitising medication or with underlying photosensitive diseases.
Explain the main features of Phototherapy - PUVA.
UVA dose: MOP tablets = 1-2 hrs before irradiation, topical = applied immediately before irradiation. Unlicensed.
Px remain photosensitive until psoralen cleared from body, re-sunscreen.
Tx given 2x a week for up to 10 weeks until psoriasis clears, can cause nausea.
Prolonged PUVA exposure increase risk of non-melanoma skin cancer and skin photoaging.
Explain the main features of systemic therapy - immunosuppressants (MTX).
Interferes with DNA synthesis by preventing the formation of tetrahydrofolate.
Explain the main features of systemic therapy - immunosuppressants (Ciclosporin).
Blocks intracellular T-cell component activation.
Results in inhibition of calcineurin phosphatase inhibits nuclear factor of activated T-cells.
Doses: 2.5-5mg/kg can clear psoriasis in 6-8 weeks.
Explain the main features of systemic therapy - immunosuppressants (Acitretin = Neotigason)
LFTs and lipid profile at start of therapy then every 2-4 weeks for 2 months then 3 monthly.
C/I/cautions: MTX or tetracycline, avoid in children.
Can cause dryness of mucous membranes, skin, conjunctiva
Explain the main features of oral retinoids.
Teratogenic:
- Rx for female px in PPP valid for 7 days and limited to 30 days of tx.
Explain the main features of biologics.
MCA and fusion protein
Interferes with T-cell function
What counselling points is given for psoriasis?
Can’t be cured but can be controlled.
Isn’t infectious
Doesn’t develop into skin cancer.
Can’t be spread to other areas of skin through topical tx.
