Download - Psoriasis. Definition and causes Types GP management Pitfalls Hospital treatments Case studies
Psoriasis
• Definition and causes• Types• GP management• Pitfalls• Hospital treatments• Case studies
Psoriasis• Definition
a chronic relapsing and remitting scaling skin disease which may appear at any age and affect any part of the skin
• Prevalence 1.5-3%• Age onset 20-30y or 50-60y
What causes psoriasis ?
• T cell mediated autoimmune disease
→ increased keratinocyte proliferation
• Environmental and genetic factors
Psoriasis• GeneticsGenetics
73% monozygotic twins concordant 73% monozygotic twins concordant V 20% dizygotic twinsV 20% dizygotic twinsif 1 parent affected if 1 parent affected →→14/40% risk for 14/40% risk for offspringoffspring
• Environmental triggersEnvironmental triggers
Types of psoriasis
• Plaque• Guttate• Rupioid• Unstable• Pustular• Erythrodermic• ?palmo-plantar pustulosis
GP Management
• Time (for proper examination and to communicate with the patient)
• Explanation
• Information and support sources (patient.co.uk, psoriasis-association.org.uk)
• Follow-up
Topical treatments
• Vitamin D analoguesDovonex (calcipotriol)Dovobet (calcipotriol & betamethasone)Silkis (calcitriol)Curatorderm (tacalcitol)Zorac (tazarotene)
• Dovonex cream and scalp application no longer available
Topical treatments• Tar
Carbo-domeExorexPsoridermAlphosyl HCSebcoCocoisTar-based bath oils & shampoos
Topical Treatments
• SteroidsOften in conjunction with Vit D analogue as Dovobet or separate steroidEumovateTrimovateScalp preparations (eumovate to dermovate strength)
• BE CAREFUL (but not mean)
Topical Treatments
• DithranolDithrocreamMicanolPsorin
• Stains skinHas to be washed offStart and low strength and build up
Topical Treatments• Scalp
Remove scale firstCocois or Sebco messy but effective
Tar or salicylic acid shampoo
Topical steroids if necessary for short periods
Pitfalls
• 'It's not working Doc'• It did work, but then he stopped using
it and the psoriasis returned• It was too
greasy/time-consuming/smelly so he stopped using it
• He wasn't applying it properly• It really didn't work
Hospital Treatment• Out-patient advice and support• UVB• PUVA• Acitretin• Methotrexate• Ciclosporin• Biologics• Admission (tar, other topicals)
UVB phototherapy
• Suitability – age, PH skin cancer, medication, radiotherapy, photosensitive disease
• X3 / week for ~6 weeks• Shield genitalia, uninvolved sites• SE burning (30%)• ↑ risk skin cancer (screen yearly if
>150 treatments)
PUVA• Suitability – as for UVB + CI in renal/hepatic
disease, cataracts, pregnancy, children
• X2 / week for ~6-8 weeks
• Need eye protection for 24 h after psoralen
• SE burning, nausea, itch↑ risk skin cancer (screen yearly if >150 treatments)
Acitretin
mec: affects keratinocyte differentiation
CI: ? fertile women (as must avoid pregnancy for 2 years)
SE: dry lips, teratogenicity, abnormal LFT, lipids, DISH
Methotrexatemec: inhibits DNA synthesis by inhibiting dihydrofolate
reductase → reduces proliferation of lymphocytes + keratinocytes
CI: pregnancy, lactation, infection, liver/renal disease, peptic ulcers
given once weekly
SE: anorexia, nausea, myelosuppression, hepatotoxicity, mouth ulcers, pulmonary toxicity, oligospermia, skin cancer
Interactions: NSAIDs, septrin, trimethoprim, penicillin, phenytoin
CiclosporinMec Inhibits T cell activation
CI uncontrolled HBP, malignancy, infection
SE HBP, nephrotoxicity, skin cancer, other malignancy, gum hypertrophy
Not recommended for long term treatment
New Biologicals
Anti TNF drugsinfliximab
etanercept
Adalimumab
Targeted T - cell therapyalefacept (binds CD2 & blocks LFA3)
efalizumab (binds to LFA-1 & blocks ICAM-1)
GP Issues• Know what your patient is on (?record
as outside script on EMIS)• Know what monitoring you are
responsible for• Keep a look out for myelosuppression• Don't be afraid of your local Derm
department!
Case Studies• Paul, age 45
• Carpet fitter
• Large plaque psoriasis knees, elbows, natal cleft. Hand and nail involvement
• Also has MS
Case studies
• Anne, age 15• Recent onset guttate psoriasis• Wants skin to be clear for sister’s
wedding
Case studies• David, age 25
• Severe psoriasis
• Has had multiple admissions, MTX, Ciclosporin, acitretin, UVB
• Treatment so far has produced partial success only
• Very keen to improve his skin as finds holding down a job very difficult