Psoriasis vulgaris

• Peak = 22.5yo

• Early presentation = more severe

• 2-3% population

• late teens -> 50s

• Polygenic trait

• 1/3 have relative

• 25% have associated arthritis

• Assoiceted with DM

• PASI - psoriasis area severity index

  • combines severityL eryteam, induration and desquamation and % area affected

Trigger

• Physical trauma -> Koebner phenomenom

• Smoking

• Infection

  • Strep: Guttate psoriasis

• Stress

  • 40% of flares

• Drugs

  • Systemic corticosteroids

  • oral lithium

  • anitmalarials

  • NSAIDs

  • interferon

  • B-blockers

  • EtOH

• although sunlight improves; 5% may get flare after sunlight exposure

Pathogensis:

• inc. turnover of keratocytes

  • normal keratinocytes take 28d to migrate -> surface

  • psoriasis = 4/7

• inc. CD8 & T-cells

Types

Eruptive/inflammatory

• multiple small (guttate/nummular)

• tendency towards resolution

• rare - 2%

Chronic stable (plaque psoriasis)

• majority of cases - 80%

Skin lesions

• Itch = common

  • scalp

  • ano-genital lesions

Sharply demarcated/marginated erythematous plaque with silvery white scale

• Scale

  • lamellar

  • loose

  • easily removed by scratching

    • Auspitz sign

• Papules -> plaques

• coalesce

  • polycyclic, serpigoius patterns

Acute guttate:

• after strep/urti

• salmon pink +/- scale -> scrape

• concentrated on trunk

• resolves spontaneously after \~ 4 weeks but may evolve to chronic plaque psoriasis

Chronic stable/plaque:

• loosely adherent scale

• polycyclic/geographic

• can adhere tightly; hyperkeratosis (shell of oyster)

• Extensor surfaces: scalp, palms, soles

• bilateral

• often symmetrical

Flexural (inverse)

Special sites:

Palms/soles:

• may be only area affected

• cracking/painful fissures/bleeding

Scalp:

• doesn’t lead to hair loss

Face

• uncommonly involved

• often refractory

Bodyfolds/groin:

• not scaly as too moist

• sharp demarcation differentiates from fungal infection

Nails

• Frequently involved (25%)

• often with arthritis

• Pitting

• subungal hyperkeratosiss

• onchylosis

• yellowish/brown spots under nail plate

Pustular psoriasis

• incidence less cf. vulgaris

• 50-60yrs

• F>M 4:1

• eruptions come and go

• itchy

• Skin:

  • pustules in stages of development (2-5mm)

  • deep seated

  • yellow

  • limited to palms + feet

• persistent for years

Generalised acute pustular psoriasis

• rare: adults

• life threatening

• burning, fiery, red, erythematous

• spreads within hours

• pinpoint sterile pustules

• fever

• leukocytosis; cytokines/chemokines

• Waves of pustules

Psoriatic Arthritis

• seronegative arthritis

• Asymetric peripheral joint involvement

  • upper limb/smaller joints

• 10% will have no visible skin lesions

• may lead to arthritis mutilans

  • telescope fingers

  • mutilation of hand

  • considerable functional impairment

• 5 different types of psoriatic arthritis:

  1. Asymmetrical arthritis

     1. involves small joints,

        1. few erosions

        2. good preservation function/little deformity

     2. symmetrical polyarthritis

        1. erosive

        2. deforming

        3. disabling

        4. distal cf. prox interphalangeal joints are affected

     3. Ankylosing spondylitis with or without peripheral arthritis

        1. commonly associated with HLAB27 - 40%

• Greater impairment to QoL

• Longer disease duration

• greater self reported disease severity

Erythrodermic:

• abrupt withdrawal of systemic therapy

• allergic reactions

• smoking

• infection

• lithium, antimalarias

Management of psoriasis:

• Fatty cream ( + 10% urea or 2% salicylic acid in white soft paraffin

• Coal tar/pinetar

  • dec. itch and scale

  • ?how works

  • Rx:

  LPC 10%, salicylic acid 2% in aqueous cream ad 100%. 200 g

• Corticosteroids:

  • used by majority

  • lowest potency used for limited period of time on face and other areas

• Pimecrolimus

  • non steroid

• Tachyphylaxis + flares when steroids long term

  • consider dec dose on 2-3 consectuviedays/sertoid free times

• Calcipotriol (daivonex)

  • not for severe/extensive unless Ca2++ monitored

  • not for face

  • total dose \< 5mg/week (100g or 60g scalp + 30g tube/cream…)

  • not be used at same time as salicylic acid as inactivated

• Dithranol (micanol) 1%

  • hydroxyantrones

  • apply once daily to plaques

    • rubbed in gently till no longer smears

    • rinsed off with h2o 10 minutes

    • increase application time over 7/7 to max 30 min

  • not applied to areas of thin skin

  • avoid in prey. lactation, children

Factors influencing treatment decisions:

• Age

• Type: Guttate, plaque, palmar, palmar pultular, generalised pustular, erythematous

• Site

• 1. Localised to palms/soles, scalp, scattered \<5%

  2. Generalised >30% involvement

• Ideally seen by dermatologist

• Generalised psoriasis should be managed in vary care: PUVA, MTX, biologicals

Localised psoriasis

Trunk and extremeties:

1. Topical glucocorticoids in ointment:

   1. betametasone pop. 0.05% oint (Diprasone)

   2. clobetasol pop 0.05% oint (dermol)

   3. applied after scale has been removed by soaking in h2o

2. Hydrocolloid dressing left on 24-48hrs

   • develop tolerance (tachyphylaxis)

   • max 50g/week of steroid

3. Can inject triamciolone 3mg/mL diluted with 0.9% NaCl -> must be intradermol

4. Vitamin D analogues:

   1. Calcipotrone 0.005% oint (Daivonex)

      1. apply bd max 100g/week

   2. Can be combined with topical steroid

   3. applied to \<40% boysurgace

   4. max dose to avoid hypercalcaemia

5. Topical pimecrolius 1%

   1. inverse psoriasis

   2. steroid sparing

   3. Elidel - not subsidised

      1. apply bd until symptoms resolve

6. Topical retinoids

Scalp

Mild:

• superficial scaling + thick plaques

• Tar or ketoconazole shampoo followed by betamethasone vale rate 1% lotion

  1. Pinetarsol 2.3%

  2. betamethasone alerate = betacream/betnovate

  3. coal tar + salicylic acid sulfar = coco-scalp

  4. Ketoconazole 2% shampoo may help some patients with mild scalp psoriasis

     1. use twice weekly

• dithranol 0.1% can be applied to scalp after hair washed

• Corticosteroid scalp:

  1. hydrocortisone-17-butyrate -0.1% (locoid scalp/Crelo)

  2. Betamethasone valerate 0.1% (beta scalp)

  3. Mometasone furoate 0.1% (Elocon lotion)

  4. Clobetasol porpionate 0.05% (dermol scalp)

  5. applied od/bd for short courses up to 1/12 in duration then 2-3 days / week for maintenance

  6. overuse may make worse

• Calcipotriol scalp (50mcg/ml)

  1. bd

  2. reduce frequency

  3. dose should not >60mL/week

  4. cream may be more effective

Severe:

1. removal of plaque before active treatment

   1. 10% salicylic acid in mineral oil overed with plastic cap and left overnight

   2. after shedding:

   3. clobetasol or calcipotrone lotion

Palms and sole:

• occlusive dressing with strong steroid (class 1)

• PUVA

• oral retinoid good for removing hyperkeratosis

Palmo-plantar pustular;

• PUVA

• topical meds ineffective

Inverse psoriasis

• topical corticosteroids

• atrophy more pronounced

Generalised

• oral methotrexate

• ciclosporin

• biologicals

Specialist referral:

• >20% body surface

• Generalised pustular psoriasis (mild, ocalised or palmoplantar pustulosis may not require ref.)

• Erythrodermic psoriasis

• Psoriatic artritis

• Localised recalcitrant psoriasis

• Psoriasis that significantly interferes with function

Phototherapy:

• may need 20-40 treatments;

• 2-3 times weekly

• narrowband UVB phototherapy

• Thin plaque; 85% achieve 90% clearance

• risks:

  • burns

  • inc. skin cancer

  • premature aging

Methotrexate:

• folate antagonist

• T-cell suppressive

• effective >60% 10-30mg

• supp. folic acid may reduce adverse effects: GI disturbance and mouth ulceration

• CI in preg and lactation

• Liver disease

• monitor:

  • blood count, LFT, Cr q1-3/12

• Can’t have other folate antagonists:

  • TMP/sulfonamides

Acitretin

normalising epidermal cell proliferation, differential and cornification

erythrodermic/pustular

Special authority

Ciclosprin

• rapidly effective

• 3-6 month courses

• BP and renal function

Biologicals

• infliximab/adalimumab