Psoriasis

Definition and causes Types GP management Pitfalls Hospital treatments

Psoriasis Definition A chronic, non-infectious, inflammatory skin disorder, with well defined, erythematous plaques & large adherent silvery scales Prevalence 1.5-3% Age onset 20-30y or 50-60y

Psoriasis Epidermal hyperproliferation Vascular dilatation Inflammatory infiltrate

What causes psoriasis ? T cell mediated autoimmune disease → increased keratinocyte proliferation Environmental and genetic factors

Psoriasis GeneticsGenetics 40% have FHx40% have FHx 73% monozygotic twins concordant v 20% dizygotic twins73% monozygotic twins concordant v 20% dizygotic twins 1 st degree relatives have 4-6 fold increased risk1 st degree relatives have 4-6 fold increased risk Environmental triggersEnvironmental triggers

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

GP Management Emollients Bath oils Site-specific topical treatments

Topical treatments Vitamin D analogues Dovonex (calcipotriol) Dovobet (calcipotriol & betamethasone) Silkis (calcitriol) Curatorderm (tacalcitol) Zorac (tazarotene) Dovonex cream and scalp application no longer available

Topical treatments Tar (Carbo-dome) (Exorex) Psoriderm (Alphosyl HC) Sebco (Cocois) Tar-based bath oils & shampoos

Topical Treatments Steroids Often in conjunction with Vit D analogue as Dovobet or separate steroid Eumovate (Trimovate) Scalp preparations (eumovate to dermovate strength) BE CAREFUL (but not mean)

Topical Treatments Dithranol Dithrocream Micanol Psorin Stains skin Has to be washed off Start and low strength and build up

Topical treatments Nails difficult potent topical steroids dovonex tazarotene systemic therapy

Topical Treatments Scalp Remove scale first Cocois or Sebco messy but effective Tar or salicylic acid shampoo Topical steroids if necessary for short periods

Types of psoriasis Plaque Guttate Rupioid Unstable Pustular Erythrodermic ?palmo-plantar pustulosis

Guttate psoriasis

Pustular psoriasis

Erythrodermic psoriasis

Plantar pustulosis

Acrodermatitis continua of Hallopeau

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)

Systemic therapy acitretin methotrexate ciclosporin

7-20% of patients with psoriasis have arthritis

Acitretin mec: affects keratinocyte differentiation CI: ? fertile women (as must avoid pregnancy for 2 years) SE: dry lips, teratogenicity, abnormal LFT, lipids, DISH

Methotrexate mec: 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

Ciclosporin Mec 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 drugs Infliximab, etanercept, adalimumab Targeted T - cell therapy alefacept (binds CD2 & blocks LFA3) efalizumab (binds to LFA-1 & blocks ICAM-1) Anti-IL 17 receptor antibodies Brodalumab Ixekizumab

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!

SIGN 121 Patients with psoriasis or psoriatic arthritis should have an annual review with their GP involving the following: ƒdocumentation of severity using DLQI ƒscreening for depression ƒassessment of vascular risk (in patients with severe disease) ƒassessment of articular symptoms ƒoptimisation of topical therapy ƒconsideration for referral to secondary care

Streptococcal theory Streptococcal infection can:  super-antigen immune stimulation  very high cytokine excretion, especially TNF-α

In guttate psoriasis, all strep isolates from the throat stimulate this pathway. Once activated, these T cells infiltrate the skin, however the thereafter pathogenic pathways diverge: keratinocyte death & exfoliation in scarlet fever keratinocyte proliferation in guttate psoriasis

Case Studies Paul, age 45 Carpet fitter Large plaque psoriasis knees, elbows, natal cleft. Hand and nail involvement

Case studies Robert, age 35 Psoriasis since teens Lives in a hostel, alcoholic

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