Psoriasis

Question 1

what is the pathophysiology

Answer 1

Hyperproliferation of the epidermis
Abnormal differentiation of the keratinocytes
Infiltration of the dermis and epidermis with activated T-lymphocytes and neutrophils

Question 2

Aetiology / Triggers

Answer 2

Streptococcal infection (especially guttate psoriasis)
Drugs, e.g. lithium, beta-blockers, NSAIDs, ACE-I, antimalarials
UV light exposure (although generally beneficial)
Trauma, e.g. tattoo, burns, surgical scars, etc.
Hormonal changes – high levels of disease activity in puberty, post-partum, during menopause
Stress
Smoking and alcohol
Obesity

Question 3

Clinical indicators

Answer 3

Koehebner’s Phenomenon
Auspitz sign

Question 4

what is Koehebner’s Phenomenon

Answer 4

Traumatised skin resulting in a psoriatic event at the site of injury

Question 5

what is Auspitz sign

Answer 5

Appearance of small bleeding points after successive layers of scale have been removed from psoriasis plaques

Question 6

Co-morbidities in psoriasis

Answer 6

Studies show certain conditions occur more frequently than expected in people with psoriasis

Suspected that there overlapping immune-mediated inflammatory processes in the development of these conditions

Question 7

Types of Psoriasis

Answer 7

Plaque psoriasis
Guttate psoriasis
Erythrodermic psoriasis
Pustular psoriasis
Nail psoriasis
Psoriatic arthritis
Scalp psoriasis
Inverse psoriasis

Question 8

Plaque Psoriasis

Answer 8

Most common type - 90% of patients
Start as small papules
Grow and unite to form plaques
Classic silvery white, scaly appearance
Usually on the scalp, behind the ears, trunk, buttocks, and extensor surfaces (e.g. elbows and knees)

Question 9

Guttate Psoriasis

Answer 9

Initially pink papules - become scaly
‘Drop-like’ in appearance, normally trunk and limbs
After a streptococcal throat infection - possibly superantigen stimulation of immune system (teenagers)
Arises very rapidly
Responds well to treatment better than psoriatic lesions with a longer onset

Question 10

Erythrodermic Psoriasis

Answer 10

Severe variant
Widespread - massive protein loss, problems maintaining core body temperature, excessive fluid losses.
Skin feels hot but patient complains of shivering, malaise
Aggressive treatment - hospital
Can be precipitated by withdrawal of systemic or potent topical corticosteroids

Question 11

Pustular psoriasis

Answer 11

Severe form
Superficial pustulation of the lesions
Often palms and soles
May be generalised - associated with fever and malaise, fluid and electrolyte disturbances and infection.
High relapse rate - can be fatal.
Hospitalised

Question 12

Nail Psoriasis

Answer 12

More often fingernails than toenails
4 main changes:
- onycholysis
- pitting
- accumulation of subungual debris
- colour changes

Question 13

Psoriatic Arthritis

Answer 13

Up to 30% psoriasis patients
Peripheral interphalangeal joints
Difficult to distinguish from rheumatoid arthritis
Rheumatoid factor not elevated

Question 14

Inverse (or Flexural)Psoriasis

Answer 14

Smooth, inflamed lesions
Mostly in creases or folds
Perianal skin in children
Beneath breasts in women
Minimal or absent scaling

Question 15

Scalp Psoriasis

Answer 15

Clinical appearance can vary from light scaling to grossly thickened scales stuck to the hair shafts.
Scales may become confluent and the entire scalp can be involved.

Question 16

Management Treatment Aims

Answer 16

induce a remission period
increase the time between relapses
make the psoriasis tolerable

Question 17

Management - treatment used

Answer 17

Lifestyle-directed advice (all)
Topical treatments for mild to moderate disease (1st line)
Emollients
Topical corticosteroids
Vitamin D analogues
Phototherapy (2nd line)*
Systemic therapy (3rd line)*
Immunosuppressants, e.g. methotrexate, ciclosporin
Biologics

Question 18

Topical treatments: Trunk & limbs

Answer 18

Potent topical steroid, e.g. betamethasone 0.05% (e.g. Diprosone) & SEPARATE vitamin D preparation (e.g. calcipotriol) applied once daily (one mane, one nocte) for 4 weeks

Can continue treatment involving a potent topical corticosteroid as above for up to MAX 8 weeks

Offer vitamin D preparation (e.g. calcipotriol) alone given BD from weeks 8-12 to allow 4 week break from steroid

Offer potent corticosteroid applied BD for up to 4 weeks OR a coal tar preparation 1-2 times daily

Question 19

Topical treatments: Scalp

Answer 19

Treating scale: Preparations to remove thick, adherent scale, e.g. Sebco ointment, Cocois ointment (coal tar + salicylic acid) can be used and rinsed off after 1hr or overnight

Treating redness / inflammation: Potent steroid, e.g. betamethasone or mometasone scalp application daily for 4 weeks then PRN ongoing

If no improvement at 4 weeks, options include trying a different scalp preparation (e.g. switch liquid to foam) OR switch to combined betamethasone and calcipotriol product (Enstilar foam or Dovobet gel) OD for 4 weeks then PRN

Maintenance therapy: Once or twice weekly coal tar shampoo (e.g. Capasal) or Once or twice weekly potent topical steroid as above

Question 20

Topical treatments: Face, flexures, genitals

Answer 20

Short-term mild or moderate potency corticosteroid ONCE or TWICE daily max 2 weeks

Topical calcineurin inhibitor (e.g. tacrolimus or pimecrolimus) BD for up to 4 weeks

Question 21

Vitamin D AnaloguesCalcipotriol, calcitriol, tocalcitol

Answer 21

RATIONALE/MECHANISM: Affect cell division and differentiation
DOSING:
Maximum weekly cumulative dose = 5mg calcipotriol
Use once or twice a day
Notice effect - week 2;Maximum effect - weeks 6-8
ADVERSE EFFECTS:
Skin irritation (do not use on face or flexural areas)
Peripheral ring of scales around treated lesions
Hypercalcaemia (rare)

Question 22

Other topical Preparations

Answer 22

COAL TAR
Proprietary products generally used now rather than specially prepared
May stain hair and fabric, can cause skin reactions, including contact dermatitis & photosensitivity
Preparations – lotions for trunk (e.g. Exorex), ointment / shampoo for scalp (e.g. Sebco, Capasal)
SALICYCLIC ACID:
Ingredient in combination preparations to help manage scale (e.g. Diprosalic, Sebco)
DITHRANOL
Less commonly used, requires special manufacture

Question 23

2nd line Specialist Treatment: Phototherapy

Answer 23

Offer / refer for if can’t be controlled by topicals alone OR if severe form OR extensive area affected
UVB radiation OR PUVA therapy (Psoralen + UVA)
Peak effect - 48-72 hours post therapy
Not if history skin cancer or in children

Question 24

3rd line Specialist Treatment: Systemic therapy

Answer 24

Non-biological systemic therapy can be offered to people with any type of psoriasis if:
It can’t be controlled by topical therapy AND
It has a significant impact on physical, psychological, social wellbeing AND
1 or more of the following apply:
Psoriasis is extensive (e.g. >10% BSA affected)
Psoriasis is associated with significant functional impairment / distress
Phototherapy has been ineffective or cannot be used

Question 25

Methotrexate (1st line) specialist

Answer 25

Amber medicine – require shared care arrangements
DOSE
Usual dose between 5-25mg ONCE WEEKLY & need folic acid 5mg weekly 48hrs after methotrexate
MONITORING
FBC, LFT, U&E baseline, 2 weekly for 6 weeks, monthly for 3 months then 3 monthly
CAUTIONS / RISK
Photosensitivity
Teratogenic (effective contraception)
Blood disorders (report oral ulceration, sore throat, abnormal bruising, etc. Significant interaction with trimethoprim)
Infection & malignancy risk
nephrotoxicity / hepatotoxicity risk
Require annual influenza vaccine and pneumococcal vaccine. No live vaccines

Question 26

Ciclosporin (2nd line)

Answer 26

Amber medicine – require shared care arrangements
DOSE: 2.5-5mg/kg daily in 2 divided doses
Brand Rx, e.g. Neoral
Same vaccine advice per methotrexate
Monitor: blood pressure, kidney function, full blood count, liver function, blood glucose, lipids
ADRs – HTN, nephrotoxicity, benign gingiva hyperplasia, hyperlipidaemia, infection, cancer risk in long term use
Interactions: CYP450 metabolized, e.g. macrolides, anti-epileptics, diltiazem, verapamil

Question 27

Retinoids- Acitretin red list

Answer 27

MECHANISM: Vitamin A derivative – has anti-inflammatory and anti-proliferative effect
WHEN USED:
Most effective for pustular and erythrodermic psoriasis
Limit to severe forms and where other systemic choices unsuitable
CAUTIONS:
Teratogenic – must be on pregnancy prevention programme
Avoid in severe liver and kidney disease
MONITORING: liver function and blood lipids
SE: drying, cracking of lips, eye inflammation, hepatic disorders

Question 28

Biologic Therapy AgentsE.g. adalimumab, etanercept, ustekinumab

Answer 28

Next option if no response to phototherapy and non-biologic systemics
Red list medicines (hospital only)
Some important safety precautions
Pre-monitoring for TB and hepatitis (risk reactivating)
Obtain and update (if needed) vaccination history prior to starting – no live vaccines for at least 4 weeks before, during and 3 months after treatment
Pneumococcal vaccine (with 5-year booster) and annual influenza vaccination needed
monitor for allergic reactions
Some carry carcinoma risk