Skin conditions: Psoriasis Flashcards
Define Psoriasis.
Psoriasis is an autoimmune condition that causes thick, scaly plaques to form on the skin. In psoriasis patients usually experience periods of flare ups and remission.
Which demographics are most likely to be affected by psoriasis?
Development usually peaks in the late teens to early 30s and then from between 50 - 60 years.
The condition affects men and women equally.
What percentage of the UK population suffers with psoriasis?
2-3%
What causes psoriasis?
Normal keratinocytes take 3 weeks to one month to migrate from the stratum basal to the stratum corneum. Whereas in psoriasis keratinocytes migrate in 3-4 days meaning that the rate of proliferation and migration of keratinocytes outweighs the rate at which they are shed leading to the production of plaques (thickened keratinocytes) on the skin. Inflammatory cells are then increased in all layers of the skin.
What is the genetic predisposition associated with psoriasis?
Approximately 1 in 4 children with a parent with psoriasis will go on to develop it.
However it is relatively complex as it involves multiple genes in its development.
What are some of the trigger events which cause those with underlying genetics to develop psoriasis?
Usually an external trigger such as:
Stress
Infection (Streptococcal infection)
Injury to skin
Virus (HIV or HPV)
Withdrawal of corticosteroids
Disease can be precipitated by NSAIDS, Lithium, Beta blockers
What is the clinical presentation of plaque psoriasis?
Red, sore, itchy, plaques that have white or silvery scales.
These plaques are well demarcated from the rest of the skin.
What is a complication of plaque psoriasis?
Psoriatic arthritis
Where does psoriatic plaques usually occur?
Palms
Soles
Where the skin touches the skin
Why is the skin read underneath the scales?
Due to increased vascularisation in order to try and compensate for the increased proliferation of keratinocytes.
What is the clinical presentation of scalp psoriasis?
Build up of thick scaly skin which has lead to dandruff like flakes on the scalp.
If severe it can thinning of the hair
Which part of the head does scalp psoriasis specifically occur?
Hairline
Forehead
Neck
Ears
What is guttate psoriasis?
Widespread psoriasis often occurring on the back, torso and limbs and presents as little raindrops that are bright pink or red on fair skin or more darkening on dark skin.
It usually clears up by itself.
What triggers guttate psoriasis?
Strep throat
What demographics often experience guttate psoriasis?
Children or young adults
What is the clinical presentation of pustular psoriasis?
It is the formation of small white or yellow fluid filled blisters on top of red or darkened skin.
Upon bursting these crust over.
Can be quite painful.
Where does pustular psoriasis usually occur?
On the palms of the hands or the soles of the feet
If a patient presents with pustular psoriasis what is the appropriate management?
Referral to a dermatologist, especially if it is widespread on the body this requires urgent medical attention
Which patients tend to present with nail psoriasis?
Often co-exists with plaque and other types of psoriasis.
Occurs in up to 50% of psoriasis patients and 80% of psoriatic arthritis patients
Which nails are most affected by nail psoriasis?
Fingernails and/or toenails
What is nail psoriasis often mistaken for?
Fungal nail infections
What are some of the symptoms nail psoriasis?
Nail discolouration, pitting, crumbling, cracking, splitting, detaching
What are some of the genotypes that are more prone to psoriasis development?
Mutations within the:
PSORS1
Interleukin 23R
Interleukin 12B
State the topical treatments for psoriasis.
Moisturisers and emollients
Vitamin D derivatives
Topical steroids
Dovobet
Coal tar preparations (scalp)
Dithranol
Calcineurin inhibitors
What are some of the Vitamin D derivatives used?
Calcipotriol
Tacalcitol
Calcitrol
What is the purpose of using Vitamin D derivatives?
Inhibits proliferation and induces differentiation of the keratinocytes which normalises keratinocyte growth.
What are some of the topical steroids used?
Eumovate, Betnovate, Dermovate
What is Dovobet made of?
Betamethasone and a Vitamin D derivative
What is the effects of Coal Tar preparations?
Anti-inflammatory and anti-scaling
When is it appropriate and not appropriate to use Dithranol?
It is appropriate for use on well defined plaques not on sensitive areas
How do Calcineurin inhibitors work?
Inhibit T cell responses
State the systemic treatment options for psoriasis.
In addition to phototherapy, systemic treatments for psoriasis include:
Immunosuppressants
Vitamin A derivatives
Apremilast
Dimethyl fumarate
Anti -TNF
Anti-IL23
Anti-IL17/IL17A
Which immunosuppressants are used in the treatment of psoriasis?
Methotrexate and Ciclosporin
Which Vit A derivative is used?
Acitretin
How does Apremilast work?
Inhibits phosphodiesterase 4 which causes local inflammation
How does Dimethyl fumarate work?
Activates Nrf2 which is a transcription factor which modifies our response to oxidative stress, reducing inflammation
Which anti-TNF are licensed for Psoriasis?
Infliximab, adalimumab, etanercept,
certolizumab
Which anti-IL23 are licensed for Psoriasis?
Ustekinumab (anti-Il12/Il23), guselkumab,
rizankizumab, tildrakizumab
Which anti-IL17 are licensed for Psoriasis?
Secukinumab, brodalumab, ixekizumab
What is Psoriatic arthritis?
It is an inflammatory joint disease linked to psoriasis that affects both the joints (knees, hands and feet) and tendons (heel and lower back).
When does Psoriatic arthritis usually occur?
After the development of skin lesions and is also defined by periods of relapse and remission. However it can occur before skin manifestations occur.
Does psoriatic arthritis always occur with psoriasis?
No, and it is not linked to the severity of psoriasis.
What are some of the symptoms of Psoriatic arthritis?
Joints become tender, swollen and stiff
They appear to be worse in the morning
Eases with exercise
Can get inflammation of the tendons without the joints
Linked closely to nail psoriasis as 80% of these patients also have nail psoriasis
What are the main treatment options for Psoriatic arthritis?
Painkillers
NSAIDs - Ibuprofen, Diclofenac, COX-2 inhibitors
Corticosteroids - systemic
DMARDs - Leflunomide
Biologics
- Anti-TNF
- Apremilast
- Tofacitinib JAK inhibitor (IL-6 induces JAK which induces STAT transcription factor which causes IL-6 mediated reactions within the cell)
How does Tofacitinib work?
IL-6 induces JAK which induces STAT transcription factor which causes IL-6 mediated reactions within the cell
