Psoriasis Flashcards
A 20-year-old female presents with several months’ history of worsening rash, mainly on her limbs. It started on her elbows and knees. It is itchy. She is otherwise well but has been suffering with stress for some time.
What is the most likely diagnosis? Select one option.
- Seborrhoeic eczema
- Atopic eczema
- Discoid eczema
- Psoriasis
- Allergic dermatitis
Psoriasis
Psoriasis is a condition where there is inflammation of the skin, and signs of psoriasis are red spots or patches which characteristically become scaly as shown in this picture. It tends to come and go, and the severity of the condition can vary.
Patients with psoriasis make new skin cells more quickly than normal, and this leads to inflammation of the skin. The exact aetiology is unknown, but it is thought to be a combination of autoimmune, genetic and environmental factors at play. Patients with psoriasis are also more prone to develop obesity, joint problems, psychological problems and are more likely to have risk factors for CVD. Therefore, in primary care, it is also important to screen for associated problems as well when managing psoriasis.
What form of psoriasis does this patient present with? Select one option.
- Pustular psoriasis
- Guttate psoriasis
- Plaque psoriasis
- Flexural psoriasis
- Erythrodermic psoriasis
Plaque psoriasis
Plaque psoriasis is the most common form, affecting 75 to 90% - patches of various sizes of red skin with white scales and can be very thick, particularly in scalp area.
Pustular psoriasis - presents with small fluid filled pustules. It can be localised (commonly affecting hands and feet), or generalised. Generalised is a medical emergency as it can be fatal. Here, you have widespread erythema and non-follicular pustules which can coalesce. The patient often has fever, malaise, a raised heart rate and is systemically unwell. They should be immediately referred and managed in secondary care.
In guttate psoriasis most of the body is usually covered with multiple tiny teardrop-like psoriatic patches. It often follows a bacterial throat infection.
Flexural psoriasis looks different – red and shiny, due to the moist nature of the skin in the flexural areas. It affects areas such as the groin, axillae, inframammary folds etc.
Erythrodermic psoriasis presents with widespread painful red skin – severe psoriasis with more than 90% of the body affected. It is a serious condition and is potentially life threatening – It requires immediate referral and treatment in secondary care.
Which of the listed factors are known to exacerbate psoriasis? (You may chose more that one)
- Stress
- Infections
- Medications
- Smoking and alcohol
- Skin injury
- UV light
ALL
- Stress
- Infections - Bacterial (streptococcal) and fungal infection may precipitate psoriasis
- Medications - Lithium, beta-blockers, anti-malarials, ACE inhibitors and withdrawal of steroids may also cause a flare-up.
- Smoking and alcohol
- Skin injury - Psoriasis may appear in the site of a recent skin injury.
- UV light- Ultraviolet light is usually beneficial except in cases of photosensitive psoriasis.
Additionally, hormonal changes can affect psoriasis as well – female patients may find it is worse during puberty and menopause, and improves during pregnancy.
What treatments of psoriasis are commonly used in primary care? (Choose four correct answer)
- Emollients
- Vitamin D based creams
- Topical steroids
- Salicylic acid
- PUVA
- Methotrexate
- Etanercept
- Emollients
- Vitamin D based creams
- Topical steroids
- Salicylic acid
Moisturisers soften the plaques.
Salicylic acid helps to lift off the scales and is often used in combination with other preparations such as coal tar and topical steroids.
Vitamin D based creams such as calcipotriol work well on plaque psoriasis – they are easy to use and are often the treatment of choice.
Topical steroids have to be used with caution and for a short period of time. When stopped, they may cause a rebound flare-up. They are useful in combination with other preparations (calcipotriol).
PUVA-oral psoralen and ultraviolet light is used by dermatologists for severe psoriasis. Drugs which affect immune response are used for severe cases. They include methotrexate and anti-TNF drugs such as Etanercept. The risk of serious side effects must be balanced with benefits under specialist supervision.
Define psoriasis.
Psoriasis is a chronic inflammatory skin disease characterised by erythematous, circumscribed scaly papules, and plaques. It can cause itching, irritation, burning, and stinging.
It has cardiovascular and psychological comorbidities.
What sites are commonly affected by psoriasis?
Often affecting elbows, knees, extensor limbs, and scalp, and, less commonly, nails, ear, and umbilical region.
What questions might you ask to distinguish eczema from psoriasis?
- Location - psoriasis is on extensor surfaces while eczema is on flexor surfaces
- Other involvement - psoriasis affects:
- Nails - pitting, riidging, onycholysis in psoriasis
- Scalp - often invovled in psoriasis
- Joint involvement - might get pain in psoriasis
- Age of onset - usually later for psoriasis than eczema
FH will probably not help as there is often FH of eczema and psoriasis.
Is this psoriasis?
No - this is seborreic dermatitis/eczema - usually occurs in middle aged men and has a T zone, back and chest distribution (oily areas).
It ill ILL DEFINED but may show some scaling.
What is the aetiology of psoriasis?
Typically lifelong, with a fluctuating course of exacerbations and remission of lesions, which may be aggravated by genetic, infectious, emotional, and environmental factors.
Aetiology unknown but suggested:
- Genetics - strong FH usually present
- Immunology - lesions are associated with increased activity of T cells in underlying skin and are made worse by medications which affect Th1 or th17 pathways. Or who have HIV.
- Infection - guttate psoriasis follows URTI e.g. streptococcal pharyngitis. Viral infection and immunisation have also been linked to flares of psoriasis.
Describe the pathophysiology of arthritis. Wha is the silver scale made up of?
- Hyperproliferation + complex cascade of inflammatory mediators
- Mitosis of basal and suprabasal cells is increased –> cells migrate to stratum corneum in a few days –> silver scale of dead cells on the surface of lesions
- Condition primarily driven by Th1 cells –> IL-17 and IL-23 cytokine production. Inhibition of these shows efficacy in treatment of psoriasis.
What are the 6 different types of psoriasis?
- Plaque psoriasis
- Guttate psoriasis
- Pustular psoriasis
- Erythroderma (erythrodermic psoriasis)
- Psoriatic arthritis
- Keratoderma blennorrhagicum (reactive arthritis)
What does guttate psoriasis look like? When does it commonly occur?
Widespread, erythematous, fine, scaly papules (water drop appearance) on trunk, arms, and legs.
The lesions often erupt after an upper respiratory infection.
Describe plaque psoriasis.
- Raised inflammed plaque lesions
- Superficial silvery-white scaly eruption
- Scale can be scraped away –> inflammed friable skin
Describe the main features of pustular psoriasis.
- Rare and SEVERE
- Involves widespread inflammation of skin and small white/yellow pul-filled blisters/pustules
- Pus is made of WBC and is not infectious
Can be palmoplantar pustulosis - chronic involvement of hands and feet
Describe erythrodermic psoriasis.
- Uncommon, aggressive inflammatory psoriasis
- Can cause a peeling rash across the entire surface of the body
How do you manage psoriasis? (not on Sofia)
Aims: You want to make plaques soft so the top scales off (emollients/salicylic acid) and then help the inflammation underneath (Vit D and corticosteroids)
Topical corticosteroids (e.g. hydrocortisone 2.5%) and/or topical vitamin D analogue (calcipotriol 0.05%)
For more severe cases:
- Phototherapy - narrow band UVB 2-3 times weekly
- Methotrexate
- Oral phosphodiesterase-4 (PDE-4) inhibitor
- biological therapy like infliximab; oral retinoid; ciclosporin; re-PUVA
What types of psoriasis are these? Which are dangerous?
TL/?BR - erythroderma - if there is 90% skin involvement then this is an emergency (“red man syndrome”) becase fluid and electrolyte balance will likely be disrupted and wet wraps are required, as well as fluid balance monitoring. Pustules can be seen (white)
TR - guttate/small plaque psoriasis - after strep throat infection; tear drop plaques; self-limiting
BL - flexural psoriasis, may also affect genitals; wheepy if secondary infection
