Psoriasis Flashcards
(28 cards)
what is the pathophysiology
Hyperproliferation of the epidermis
Abnormal differentiation of the keratinocytes
Infiltration of the dermis and epidermis with activated T-lymphocytes and neutrophils
Aetiology / Triggers
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
Clinical indicators
Koehebner’s Phenomenon
Auspitz sign
what is Koehebner’s Phenomenon
Traumatised skin resulting in a psoriatic event at the site of injury
what is Auspitz sign
Appearance of small bleeding points after successive layers of scale have been removed from psoriasis plaques
Co-morbidities in psoriasis
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
Types of Psoriasis
Plaque psoriasis
Guttate psoriasis
Erythrodermic psoriasis
Pustular psoriasis
Nail psoriasis
Psoriatic arthritis
Scalp psoriasis
Inverse psoriasis
Plaque Psoriasis
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)
Guttate Psoriasis
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
Erythrodermic Psoriasis
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
Pustular psoriasis
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
Nail Psoriasis
More often fingernails than toenails
4 main changes:
- onycholysis
- pitting
- accumulation of subungual debris
- colour changes
Psoriatic Arthritis
Up to 30% psoriasis patients
Peripheral interphalangeal joints
Difficult to distinguish from rheumatoid arthritis
Rheumatoid factor not elevated
Inverse (or Flexural)Psoriasis
Smooth, inflamed lesions
Mostly in creases or folds
Perianal skin in children
Beneath breasts in women
Minimal or absent scaling
Scalp Psoriasis
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.
Management Treatment Aims
induce a remission period
increase the time between relapses
make the psoriasis tolerable
Management - treatment used
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
Topical treatments: Trunk & limbs
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
Topical treatments: Scalp
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
Topical treatments: Face, flexures, genitals
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
Vitamin D AnaloguesCalcipotriol, calcitriol, tocalcitol
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)
Other topical Preparations
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
2nd line Specialist Treatment: Phototherapy
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
3rd line Specialist Treatment: Systemic therapy
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
