Psoriasis Flashcards
What are the features of classic chronic plaque psoriasis?
- Scaly, red plaques with silvery scale
- Affects buttocks, extensor surfaces, knees, elbows, scalp, ears
- Erythematous red base
- Plaque bc proper step up in skin
- If pick off some of the silvery scale get Auspitz sign which gives pinpoint bleeding
- Can be itchy and painful
What are the nail changes in psoriasis?
1) Nail pitting
2) Salmon patches - yellow oily discolouration of nails
3) Onycholysis - serration of nail from nailbed
4) Subungual hyperkeratosis - thickening of the skin underneath the nails
5) Brittle and painful fingernails
Describe guttate psoriasis
- Rain drop plaques of psoriasis
- Classically presents a few weeks after strep throat infection (trigger)
- Respond v well to light treatments
Describe inverse psoriasis
- No classical scaly features
- Red, shiny rash
- Well demarcated
- Can be confused with intertrigo - bacterial/fungal infection in creases, sweaty, moist areas in skin
Describe flexural psoriasis
- Red, shiny rash in flexural areas e.g. armpit
- Less scale bc moist area
- Scaly around the edge where it is less moist
- V well demarcated
Describe genital psoriasis
- May lack scale, moister area
- Significant impact on QoL, sexual function
- Misdiagnosed as fungal infection e.g. candida, incorrect treatments, need to recognise it and treat early
- Patient concern re topical steroids in this area - always ask patient if psoriasis affects this area
Describe scalp psoriasis
- Cap of scale on scalp
- Associated hair loss
- When treat psoriasis well, hair does generally grow back quite normally
Describe photo-aggravated psoriasis
Red rash only where has been exposed to sun
Why is photo-aggravated psoriasis unusual?
Bc mostly psoriasis gets a lot better in the sun and is treated with UV treatments
What is the Kobner phenomenon?
- Rash tracking in sites of trauma e.g. to scars or where skin has been traumatised in anyway
- Psoriasis comes up in these areas
- Also seen in other conditions
Describe palmoplantar psoriasis
- Very thick hyperkeratotic skin on soles of feet and palms of hand
- Very encased - patients can peel off sheets of skin
- Sometimes confused with atopic dermatitis which can have similar appearances of hyperkeratosis - but look for scaly plaques elsewhere or nail changes indicative of psoriasis
- Very uncomfortable to walk or use hands - get deep fissures in skin where it has cracked
What are the two peak age groups of onset of psoriasis?
2nd/3rd decade and 6th decade
What are the precipitating factors for psoriasis (on top of genetics/family history)?
1) Streptococcal pharyngitis or other infection
2) Emotional stress
3) Physical trauma
4) Drugs - lithium, beta blockers, NSAIDs, antimalarials
5) HIV infection
What happens in psoriasis?
1) Skin specific effects trigger psoriasis
2) This stimulates innate and adaptive immunity which causes propagation of psoriasis
3) This leads to increased cell turnover and vasodilation causing excess skin with silvery scale
What are some of the inflammatory pathways involved in psoriasis?
1) Impaired barrier function
2) APCs cause propagation of inflammatory pathways e.g. IL-17, IL-23, TNFalpha (and IL-22?) which drive psoriasis
What are comorbidites of psoriasis?
1) Depression
2) Diabetes
3) Psoriatic arthritis
4) Heart disease (but other risk factors also present)
5) Obesity
6) Metabolic syndrome
What lifestyle change can lead to an improvement in psoriasis?
Weight reduction
What indexes are used to measure the effect of psoriasis on mental health?
1) Dermatology life quality index (DLQI 1-30)
2) Patient health questionnaire (PHQ9)
3) Generalised anxiety disorder (GAD7)
What does severe psoriasis increase your risk of?
- Stroke and MI
- Depression, anxiety, suicidality
Where is the majority of psoriasis treated?
In primary care
How is psoriasis treated topically?
1) Thick moisturisers (2-3 times a day in flare)
2) Corticosteroid ointments
3) Vitamin D analogues (combination or monotherapy)
4) Tar/retinoids on skin e.g. dithranol - good for stubborn thick plaques on skin
What is the problem with topical steroids?
- Can get rebound
- After using a strong, potent topical steroid when you suddenly stop using it psoriasis can come back worse
- So tend to use slightly weaker topical steroids and then gradually wean them off
How is phototherapy used to treat psoriasis?
- UV has an immunosuppressive effect on the skin
- Will give them 6 months relief
- May be a good maintenance treatment and all they need
- Contraindications = previous skin cancer or v fair skin which is likely to burn
What medications are prescribed as 2nd line systemics (prescribed by dermatologists) in psoriasis?
1) Methotrexate
2) Acitretin - good for thickened skin, helps reduce hyperkeratosis
3) Cyclosporin - v effective, can’t use long term (> year) bc can cause damage to kidney and high BP so often rescue therapy
4) Fumaric acid esters
5) Apremilast - used in patients not suitable for a biologic
