Psoriasis Flashcards
Define psoriasis [1]
Psoriasis is a chronic inflammatory skin condition characterised by clearly defined, red and scaly plaques.
Caused by the hyperproliferation of the epidermis.
Describe the clinical presentation of psoriasiss
- Erythematous, circumscribed scaly papules and plaques on elbows, knees, extensor surfaces of limbs, scalp, and, less commonly, nails, ears, and umbilical region. Silvery scale with well demarcated plaques
- Symmetrical
- Most commonly on extensor surfaces
- Well defined plaques (compared to eczema) with matching morphology
- Gets better when exposed to sun
- FHx
- 20% have psoriatic arthritis: joint pain, tendinitis etc. In most cases arthritis presents after the onset of cutaneous psoriasis
State the different types of psoriasis [5]
Guttate psoriasis (post streptococcal infection)
- Widespread small plaques
- Often resolves after several months
Chronic plaque psoriasis
* Persistent and treatment-resistant
* Plaques >3 cm
* Most often affects elbows, knees, and lower back
* Ranges from mild to very extensive
Flexural psoriasis (inverse psoriasis)
* Affects body folds and genitals
* Smooth, well-defined patches
* Colonised by candida yeasts
Pustular psoriasis
* Acute generalised pustular psoriasis (von Zumbusch): rare, severe, urgent.
Sebopsoriasis
* Overlap of seborrhoeic dermatitis and psoriasis
* Affects the scalp, face, ears and chest
* Colonised by malassezia
Nail psoriasis
* Pitting, onycholysis, yellowing, and ridging
* Associated with inflammatory arthritis
Guttate psoriasis lesions often erupt after an upper respiratory infection.
Which age group do they most commonly occcur in? [1]
Where specifically do they occur?
Guttate psoriasis:
* more common in children and adolescents
* Widespread, erythematous, fine, scaly papules (water drop appearance) on trunk, arms, and legs
Describe the onset of guttate psoriasis [1]
tends to be acute onset over days
Describe how you differentiate guttate psoriasis to pityriasis rosea with regards to:
prodrome [1]
appearance [1]
treatment [1]
Guttate psoriasis:
- Precieded by streptococcal infection 2/4 weeks ago
- Tear drop scaly papules
- Most resolve spontaneously with 2-3 months.
PR:
- Ptx report recent resp. infection but not common in qs
- Herald patch followed 1-2 weeks later by multiple erythematous, slightly raised oval lesions with a fine scale confined
- Self limiting (~6 weeks)
Describe the clinical manifestation of inverse psoriasis [2]
Smooth red patches occur in skin folds such as under the breasts, in the armpits or around genitals. It’s more common in overweight individuals and is exacerbated by friction and sweating.
Describe the clinical manifestation of pustular psoriasis [2]
Pustular psoriasis is a rare severe form of psoriasis where pustules form under areas of erythematous skin.
The pus in these areas is NOT infectious
Patients can be systemically unwell
It should be treated as a MEDICAL EMERGENCY and patients with pustular psoriasis initially require admission to hospital.
Acute pustular psoriasis is a potentially life threatening disease characterised by the development of numerous small sterile yellow pustules and widespread areas of erythema. The pustules may coalesce to form large patches of pus.
The condition may arise in patients who have had classical psoriasis for many years.
Attacks may be precipitated by [4]
Acute pustular psoriasis is a potentially life threatening disease characterised by the development of numerous small sterile yellow pustules and widespread areas of erythema. The pustules may coalesce to form large patches of pus.
The condition may arise in patients who have had classical psoriasis for many years.
Attacks may be precipitated by infection, drugs, pregnancy, or the withdrawal of topical or systemic corticosteroid therapy.
Describe the clinical manifestation of Erythrodermic psoriasis [2]
Why is this clinically significant? [1]
Erythrodermic psoriasis
- A rare form that leads to fiery redness over most of the body. It can cause severe itching and pain, and is a medical emergency as it can disrupt the body’s ability to regulate temperature.
The appearance of punctate, bleeding spots when psoriasis scales are scraped off is called? [1]
Auspitz sign
What are triggers for psoriasis? [+]
Infections
- Strep; HIV
Alcohol and stress
Drugs:
- Beta blockers, nicotine and antimalarials
- Lithium
- Antihypertensives (ACEin)
Skin injury: Koebner phenomenon
Endocrine changes
- Puberty
- Pregnancy (generally improves)
- Menopause
- Hypocalcaemia
Ethnicity
- 2x more common in white populations
How do you differentiate psoriasis between atopic dermatitis if they present similarly? [1]
Skin biopsy shows changes consistent with atopic dermatitis.
Which investigations do you perform to dx psoriasis? [2]
- Clinical diagnosis (usually no tests are necessary)
-
Consider skin bx: Intra-epidermal spongiform pustules and Munro neutrophilic microabscess within the stratum corneum
- parakeratosis, acanthosis, and elongation of the rete ridges. - Blood tests
-
Rheumatology Screening:
- Patients with psoriatic arthritis often present with skin symptoms first
- Therefore, if joint symptoms are present or if there is a high suspicion of psoriatic arthritis based on clinical judgement, rheumatology screening including serum rheumatoid factor (RF) test and anti-cyclic citrullinated peptide (anti-CCP) antibodies should be considered.
Describe the tx algorithm for plaque psoriasis
Topical treatments:
- Emollients
- Steroids - dont use alone - combine with vitamin D analogue e.g. Dovabet (combination tx)
- Salicylic acid - breaks down keratin
- Coal tar - effective anti-inflam
Phototherapy: 3x week for 3 months
- NB-UBV
- PUVA
Systemics - Oral immunosuppression
- Methotrexate
- Ciclosporin
Systemics - retinoids:
- Acitretin - Its use is restricted, generally only for those who have failed other systemic options or in whom they are inappropriate.
Biologics
Describe the management plan for a patient with psoriasis
Mild to moderate psoriasis:
- Vitamin D analogues (e.g., calcipotriol) and corticosteroids
- Tar preparations and dithranol may be considered for chronic plaque psoriasis.
Moderate to severe disease not responding to topical treatments:
- Narrowband UVB therapy (psoralen plus UVA (PUVA) therapy may be utilised if narrowband UVB is ineffective or contraindicated)
- Methotrexate, ciclosporin or acitretin can be considered in patients with severe disease or when topical treatments and phototherapy have failed
Severe disease who have failed traditional systemic therapies:
- etanercept (TNF-inhibitors)
- ustekinumab (interleukin-12/23 inhibitors)
- secukinumab (interleukin-17 inhibitors)
Describe the tx algorithm for guttate psoriasis [5]
- Most cases resolve spontaneously within 2-3 months
- Phototherapy
- Ciclosporin
- Methotrexate
- Acitretin
What score is used to rate psoriasis Disease Severity Assessment on a ptx? [1]
What score indicates moderate to severe diseae [1]
PASI
- It takes into account both the extent of body surface area affected by psoriasis and the intensity of plaque redness, thickness and scaling.
- A PASI score greater than 10 indicates moderate to severe disease.
What type of psoriasis is depicted? [1]
Guttate psoriasis
- Also termed raindrop psoriasis, it presents as a sudden eruption of small circular plaques classically 2 weeks following a streptococcal sore throat. It can also occur as a flare of disease in patients with pre-existing psoriasis.
Describe what is meant by generalised pustular psoriasis [2]
Subdivided into acute GPP and generalised annular pustular psoriasis
The pustules may coalesce forming ‘lakes of pus’. They tend to resolve over days leaving the erythema and scaring. It can represent a dermatological emergency and patients are often systemically unwell with fever, malaise and arthralgia.
In erythroderma (erythrodermic psoriasis), there is generalised erythema with fine scaling. It is often associated with pain, irritation, and sometimes severe itching.[2]
Describe how you differentiate between guttate psoriasis and pityriasis rosea with regards to prodrome, appearance and tx? [3]
Pityrisasis rosea will also have a herald patch
How would you differentiate psoriasis to eczema? [3]
Eczema:
- usually presents with intense pruritus
- lesions are typically ill-defined
- erythematous patches, papules or plaques
- The skin may become thickened from chronic scratching (lichenification).
Psoriasis:
- well-demarcated, red plaques covered by silvery scales
- Normally less severe itching
- Auspitz sign is definitive
How would you differentiate psoriasis from seborrheic dermatitis? [2]
Seborrheic dermatitis:
- Impacts areas of sebaceous glands e.g. scalp, face and central chest
- Well-defined erythematous patches or plaques with yellowish greasy scaling.
Psoriasis:
- Extend beyond the hairline unlike seborrheic dermatitis
- presence of nail changes like pitting or onycholysis would indicate
How would you differentiate psoriasis vs lichen planus?
Lichen Planus: is an ongoing (chronic) inflammatory condition that affects mucous membranes inside your mouth.:
- Flat-topped, polygonal papules that often have a violaceous hue.
- Wickham’s striae (fine white lines) may be visible on the surface.
- Oral or genital involvement is more common in lichen planus than psoriasis.
Name this manifestation of psoriasis [1]
Describe why this an derm emergency
Erythroderma
Complications include:
* Dehydration
* Heart failure
* Infection
* Hypothermia - inability to regulate temperature
* Protein loss and malnutrition
* Oedema (swelling), particularly of lower legs
* Death
Describe clinical imaging of PsA?
X-ray of affected joints:
- may show erosion of the small joints. Classic findings are erosions of the DIP with periarticular bone formation (osteophytes). In advanced disease, there may be “pencil in cup deformity” at the DIP
X-ray of the sacroiliac joints (SIJ):
- usually normal in the initial stages, but it is important to obtain a baseline radiograph for assessing disease progression
- Periostitis (inflammation of the periosteum, causing a thickened and irregular outline of the bone)
MRI of SIJ:
- looking for joint oedema (not routinely performed due to low specificity)
TOMTIP: The classic x-ray finding in the digits is a “pencil-in-cup” appearance.
ACE inhibitors
The following factors may exacerbate psoriasis:
* trauma
* alcohol
* drugs: beta blockers, lithium, antimalarials (chloroquine and hydroxychloroquine), NSAIDs and ACE inhibitors, infliximab
* withdrawal of systemic steroids
Beta blockers
Guttate psoriasis
