Psoriasis Flashcards
What is psoriasis?
A common papulo-squamous disorder affecting 2% of the population and is characterized by well-demarcated, red scaly plaques. The skin becomes inflamed and hyperproliferates at about ten times the normal rate
What immune cell is implicated in psoriasis?
T-lymphocyte
What are thought to be trigger factors for the development of psoriasis?
- Infections
- Drugs
- Trauma
- Smoking
- Alcohol
- UV light
- Genotype
What are pathological features of psoriasis?
- Increased skin turnover
- Epidermal acanthosis
- Epidermal parakeratosis
- Absent granular layer
- Polymorphonuclear abscesses in upper dermis
- Capillary dilatatio in dermis
What is the most important cytokine implicated in someone with psoriasis?
TNF-alpha - bases of some therapeutic interventions
What proportion of those with psoriasis have family members with the disease?
30%
What drugs can trigger psoriasis?
- Lithium
- NSAIDs
- B-blockers
- Antimalarials
What are typical features of psoriatic plaques?
- Symmetrical, well defined, with silvery scales
- Found on extensors surfaces
- Flexures can be affected, but plaques are less scaley
What are signs of psoriasis?
- Symmetrical, sclaey plaques on flexures
- Specific types of psoriasis - guttate, pustular, generalised
- Nail changes
- Arthritis
What is the comonest type of psoriasis?
Chronic plaque psoriasis - pinkish red sclay plaques, especially on extensor surfaces such as knees and elbows. Can be present on lower back, ears and scalp as well.
In chronic plaque psoriasis, what is the term used to describe new pllaques which have formed at sites of trauma?
Kobner phenomena
What are features of flexural psoriasis?
Well-demarcated, red glazed plaques confined to flexures such as the groin, natal cleft and sub mammary area. These are rarely scaly lesions
What are features of guttate psoriasis?
‘Raindrop-like’ psoriasis is a variant most commonly seen in children and young adults. An explosive eruption of very small circular or oval plaques appears over the trunk about 2 weeks after a streptococcal sore throat.
Where is guttate psoriasis most commonly found?
Over the trunk
What can cause guttate psoriasis?
Strep throat infection - occurs approximately 2 weeks post infection
What are features of erythrodermic psoriasis?
Usually occurs in the setting of known worsening or unstable psoriasis but may uncommonly be the first presentation of psoriasis - Acute onset of erythroderma and pustular plaques
Is erythrodermic psoriasis an emergency?
Yes
What systemic features can appear in erythrodermic psoriasis?
- Malaise
- Pyrexia
- Circulatory disturbance
What are the main types of psoriasis?
- Chronic plaque psoriasis - extensors
- Flexure psoriasis
- Guttate psoriasis
- Palmo-plantar psoriasis
- Erythrodermic psoriasis
What are features of palmo-plantar psoriasis?
Plaques: Yellow-brown pustules on palms and soles
What are nail changes seen in psoriasis?
- Pitting of the nail plate
- Distal separation of the nail plate (onycholysis)
- Yellow-brown discoloration
- Subungual hyperkeratosis
- Damaged nail matrix and lost nail plate - Rare
What proportion of those with psoriasis develop a seronegative arthritis?
5-10%
What would your differential diagnosis be for a suspected psoriatic plaque?
- Dermatitis/eczema: discoid or seborrhoeic
- Lichen planus
- Pityriasis rosea [esp. guttate psoriasis]
- 2o stage of syphilis
- Reiter’s syndrome [Esp. palmoplanar psoriasis]
- Discoid lupus
What are the general principles to managent of someone with psoriasis?
- Education
- Remove triggers
- Topical therapies
- Systemic therapies
What topical therapies might you use in someone with psoriasis?
CREVAS CKD
- Coal tar preparations - Inhibit DNA synthesis
- Retinoids - Tazarotene
- Emollients
- Vit. D analogues (Calcipotriol, tacalcitol and calcitriol) - decrease cell proliferation
- Anthralin - ↓ cell proliferation
- Salicylic acid
- Corticosteroids
- Keratolytics
- Dithranol
What systemic therapies might you use for someone with psoriasis?
- Immunosuppressants - Methotrexate, ciclosporin, azathioprine, and hydroxyurea
- Retinoids - Acitretin
-
Photochemotherpy
- UVB for classic/plaque and guttate types
- PUVA [psoralen] for palmoplanar type
What is the goeckerman regimen?
Treatment of tar and UVB light
How would you treat erythrodermic psoriasis?
Methotrexate
How would you treat guttate psoriasis?
Topical therapies and/or UVB
How would you treat palmo-plantar psoriasis?
- Potent topical steroids
- Coal tar paste
- Local hand and foot PUVA
How would you manage someone with flexural psoriasis?
- Mild steroid and/or tar topical creams
- Calcitriol and 0.1% tacrolimus ointment
What does the ingram regimen consist of?
Dithranol and UVB
What can be used in those with severe psoriatic disease?
Cytokine modulators - Anti-TNFalpha
What age group does guttate psoriasis most commonly occur in?
Children/teenagers
What is PUVA?
PUVA is a combination treatment which consists of Psoralens (P) and then exposing the skin to UVA (long wave ultraviolet radiation).
