dermatology PT 2

Question 1

what is psoriasis?

Answer 1

Chronic, inflammatory skin disease

Question 2

what abnormalities does psoriasis cause?

Answer 2

– Infiltration of the dermis and epidermis with activated Tlymphocytes & neutrophils
– Stimulation of the cutaneous vasculature leading to new
blood vessel formation in the psoriatic plaques
– Decreased epidermal turnover time (from 28 to ~4 days)-
overproduction of skin cells

Question 3

what causes psoriasis?

Answer 3

• Cause unknown, genetic aspect may
  predispose some people to the condition

Question 4

what are the key clinical features of psoriasis?

Answer 4

• A typical psoriatic lesion is red, scaly,
  sharply demarcated plaque
• May be any size and affect any part of the body
• Most common sites are extensor surfaces of elbows and knees, sacrum and scalp
• Hands and feet frequently involved
• Scale is easily scraped off revealing tiny bleeding points
• Pruritus
• Relapsing and remitting condition
• Often impact on QoL with phsycological/social
  disability

Question 5

what are the precipitating factors for psoriasis?

Answer 5

• Many people with psoriasis can pinpoint a trigger event or experience that preceded the onset of psoriasis
• Trauma
• Infection
• Hormones
• Sunlight- usually improves psoriasis but 10% worsen
• Medication e.g. beta blockers, lithium, antimalarials
• Alcohol
• Smoking
• Profound psychological stress

Question 6

what is chronic plaque psoriasis?

Answer 6

Psoriasis ‘plaques’ are formed by the build up of skin cells
* Red (increased blood supply to area), itchy, sore, white/silvery scales

Question 7

what is the difference with flexural psoriasis?

Answer 7

may have little or no scale due to friction against other skin in these areas e.g. submammary, axillary, ano-genital
folds

Question 8

what is guttate psoriasis? who does it affect? when does it happen?

Answer 8

• Usually affects children and young adults
• Can occur as first presentation of psoriasis or as an exacerbation of chronic plaque psoriasis
• Commonly follows a streptococcal throat infection
• Usually self-limiting
• Widespread small, red macules
  which become scaly but clear within a few months

Question 9

what is erythrodermic psoriasis?

Answer 9

Erythromdermic v. rare - a generalised redness of the skin involving all, or nearly all (usually stated as at least 90%) of the skin’s surface.

Question 10

when does erythrodermic psoriasis occur?

Answer 10

Usually occurs in two contexts:
* In the setting of known, progressively worsening chronic plaque psoriasis.
* It may be precipitated by infection, tar, drugs, or withdrawal of corticosteroids

Question 11

what is generalised pustular psoriasis?

Answer 11

• A v. rare generalised eruptive form of psoriasis accompanied by fever and toxicity

Question 12

what does generalised pustular psoriasis look like?

Answer 12

Acute erythema is seen with a rapid spread of
multiple sterile pustules over the body,
concentrated in the flexures, genital regions
and fingertips.

Question 13

how common is psoriatic arthritis?

Answer 13

• Affects up to 1 in 5 people with psoriasis

Question 14

how does psoriatic arthritis affect a patient? how is it treated?

Answer 14

• Most commonly affects hands and feet
• Swollen, inflamed, painful joints
• Usually involves referral to rheumatologist
• NSAIDs/ Steroids/ DMARDs/ Biologics may be
  required

Question 15

what happens in nail psoriasis?

Answer 15

• Pitting of nails, discolouration (‘oil spots’ ‘salmon patches’), hyperproliferation of nail bed, oncholysis

Question 16

what/how would you assess the condition?

Answer 16

assess disease severity, impact of disease on
physical, psychosocial, social wellbeing, psoriatic arthritis, co-morbidities

Question 16

what/how would you assess the condition?

Answer 16

assess disease severity, impact of disease on
physical, psychosocial, social wellbeing, psoriatic arthritis, co-morbidities

Question 17

where is psoriasis usually managed?

Answer 17

Usually managed in primary care, with specialist referral being needed at
some point for up to 60% of people

Question 18

what tool do you use to assess the severity of the condition?

Answer 18

PASI = psoriasis area severity index

Question 19

how does PASI work?

Answer 19

• Scoring procedure often used to evaluate psoriasis clinically and to
  measure outcomes in clinical trials.
• Scores severity of lesions (from 0-4) in terms of redness, thickness and
  scaliness, and the score is weighted according to the area affected.
• Following treatment or in clinical trials, endpoints such as PASI 75 (a 75%
  reduction in disease activity) are used to measure progress of treatment.

Question 20

what does the PGA score indicate?

Answer 20

Physician Global Assessment
* A scoring system is based on response to treatment as measured by lesion erythema, induration, and scale
* Score assignments that range from clear, almost clear, mild, moderate, to severe

Question 21

how do emollients work in psoriasis?

Answer 21

• Soften plaques, reduce itching and redness, improve absorption of topical treatments. May have anti-proliferative effect on psoriasis
• Different products may be needed for different areas

Question 22

what are the first line treatment options for psoriasis?

Answer 22

• topical corticosteroids
• vitamin D
  analogues
• dithranol
• tar preparations

Question 23

what are the first line treatment options for psoriasis?

Answer 23

• topical corticosteroids
• vitamin D
  analogues
• dithranol
• tar preparations

Question 24

what are the second line treatment options?

Answer 24

• phototherapies
• systemic non-biologic therapies:
• methotrexate,
• ciclosporin,
• acitretin

Question 25

what are the 3rd line treatment options?

Answer 25

• systemic biologic therapies:
• adalimumab
• etanercept
• Infliximab
• ustekinumab

Question 26

when may salicylic acid be used?

Answer 26

may be used to remove scale before potent steroid application if initial treatment for 4 weeks is not satisfactory.

Question 27

what guidance is there around corticosteroids?

Answer 27

– Useful in acutely inflamed plaques and on face/ flexures
– Not as effective on chronic scaly plaques
– Risk of rebound flare
* BAD guidelines for management of psoriasis with topical steroids
– Do not use regularly for more than 4 weeks without review…..patient may
need follow up appointment
– Do not use potent steroids regularly for more than 7 days
– Review every 3 months
– No more than 100g of a moderately potent or higher potency preparation
should be applied per month
– Attempt to rotate topical steroids with alternative non-steroid preparations

Question 28

what are the vitamin D analogues available?

Answer 28

• Calcipotriol, tacalcitol, calcitriol

Question 29

how long do vitamin D analogues take to work?

Answer 29

Useful in mild-moderate chronic plaque psoriasis, can clear psoriasis in 6-8 weeks

Question 30

what are vitamin D analogues MOA?

Answer 30

– Inhibit keratinocyte differentiation and proliferation
– May have some anti-inflammatory activity

Question 31

what are the benefits of VIT d analogues?

Answer 31

• Don’t smell/stain like older treatments (tar/dithranol)
• May be as effective as potent steroid , but with longer duration of remission after treatment has stopped

Question 32

what side effects may vit D analogues have?

Answer 32

• Can cause skin irritation, resulting in transient increased redness/dryness and stinging/burning
  – Calcipotriol should not be used on face/flexures
  – Calcitriol OK, less irritant

Question 33

how should vit D analogues be applied?

Answer 33

Adequate quantities should be used – 0.5g (a fingertip unit) for 10cm2 skin (one medium sized adult palm)
* Apply thickly (unlike steroids)
* Maximum weekly dose to avoid risk of hypercalcaemia
– Calcipotriol 100g, calcitriol 210g, tacalcitol 70g

Question 34

what is tazarotene? how does it work?

Answer 34

• Topically active retinoid (vitamin A derivative)
• Mechanism of action
  – Normalises keratinocyte differentiation
  – antiproliferative and anti-inflammatory effects

Question 35

why is tazarotene generally avoided?

Answer 35

• Use is limited by skin irritation and increased photosensitivity
• Teratogenic

Question 36

what is the thought MOA o coal tar?

Answer 36

thought to be keratolytic with some anti-inflammatory and antiproliferative effects

Question 37

what are the disadvantages of coal tar?

Answer 37

• Stains clothing
• Smells unpleasant
• Less effective than vitamin D preparation
  Theoretical risk of carcinogenicity- no epidemiological evidence

Question 38

what are the disadvantages of dithranol?

Answer 38

• Profoundly irritant to skin, causing inflammation and blistering
• Causes temporary staining of skin, and permanent staining of clothing and bathroom fittings

Question 39

what is used to prevent spreading of dithranol to uninvolved skin areas?

Answer 39

lassar’s paste

Question 40

how long does it take dithranol to work?

Answer 40

• Response to treatment can be expected within 3 weeks

Question 41

what is SCDT?

Answer 41

• Short-contact dithranol treatment (SCDT)
  – Application of up to 8% for between 15-30
  minutes with or without UVB
  – Suitable for home use

Question 42

what is phototherapy and how does it work?

Answer 42

• UVB (responsible for sunburn) or PUVA therapy
• Thought to modulate expression of cellular adhesion molecules and induce T-cell apoptosis
• UVB Dose adjusted to match the patient’s skin type
  – Usually 80% of minimum erythemogenic dose (MED)
  3 weeks till cleard

Question 43

what is PUVA?

Answer 43

• Combination of 8-methoxypsoralen (MOP) and UVA

Question 44

how is UVA dose determined ?

Answer 44

by assessment of skin type
– MOP Tablets: 1-2 hours before irradiation
– Topical (lotion, paint, bath solution)- applied immediately before irradiation
– unlicensed

Question 45

when is the patient not photosensitive?

Answer 45

• Patient remains photosensitive until psoralen cleared from body, therefore advise re sunscreen

Question 46

how does methotrexate work?

Answer 46

– Interferes with DNA synthesis by preventing the formation of tetrahydrofolate
– Monitoring in the same way as other indications, purple book etc

Question 47

how does ciclosporin work?

Answer 47

– Blocks intracellular components of T-cell activation through a series of interactions
– Results in inhibition of calcineurin phosphatase…….inhibits nuclear factor of activated T-cells
– Doses 2.5-5mg/kg can clear psoriasis in 6-8 weeks
– Sometimes used for maintenance but risks vs benefits.
– Drug interactions, monitoring and side-effects

Question 48

how does the oral retinoid acitretin work?

Answer 48

• Bind to nuclear receptors and regulate gene
  transcription
• Induce keratinocyte differentiation and reduce epidermal hyperplasia

Question 49

what has to be monitored with acitretin?

Answer 49

hepatotoxic so:
* LFTs and lipid profile at start of therapy, then every 2-4 weeks for 2
months then 3 monthly

Question 50

who should oral retaonids not be given in?

Answer 50

Contraindications/cautions: concomitant methotrexate or tetracycline,
avoid in children

Question 51

if a woman is of child bearing age what must she agree to with oral retinoids? how long does the prescription last?

Answer 51

Oral retinoids contra-indicated in women of child-bearing potential unless used in conjunction with a pregnancy prevention programme (PPP)
– Prescriptions for female patients in a PPP are only valid for 7 days and are limited to 30 days of treatment

Question 52

how do biologics work in psoriasis?

Answer 52

• Monoclonal antibodies and fusion proteins
• Interfere with T-cell function

Question 53

what are the general psoriasis counselling points?

Answer 53

• Psoriasis cannot be cured, but can be
  controlled
• Is not infectious
• Does not develop into skin cancer
• Cannot be spread to other areas of skin
  through application of topical treatments