Psoriasis

Question 1

What is psoriasis?

Answer 1

Psoriasis is a chronic relapsing inflammatory disorder characterised by a variety of morphological lesions that present in a number of forms. The commonest form of psoriasis is plaque psoriasis and will be the form most familiar to pharmacists.

Question 2

What is the commonest form of psoriasis?

Answer 2

Plaque psoriasis.

Question 3

If a patient has one parent with psoriasis then they have a 25 to 30% chance of developing psoriasis. If both parents suffer from psoriasis, this increases to

Answer 3

50-60%

Question 4

Psoriasis lesions develop at sites of skin trauma, such as sunburn and cuts (known as Koebner phenomenon), during periods of stress and following what throat infection?

Answer 4

Streptococcal.

Question 5

What are the only forms of psoriasis that can be managed by a community pharmacist?

Answer 5

Scalp and plaque.

Question 6

The typical distribution of psoriatic plaques is what? (5)

Answer 6

Scalp/head (not face)
Elbows. 
Knees. 
Buttcrack. 
Groin.

Question 7

Plaque psoriasis classically presents with characteristic salmon-pink lesions with what colour scales and what form of boundaries?

Answer 7

silver-coloured scales and well defined boundaries.

If the scales on the surface of the plaque are gently removed and the lesion is then rubbed, it reveals pinpoint bleeding from the superficial dilated capillaires. This is know as the Auspitz’ sign and is diagnostic.

Question 8

What is a comedone?

Answer 8

A papule which is ‘plugged’ with keratin and sebum.

Question 9

What is the difference between a bulla and a vesicle?

Answer 9

Both are clear fluid filled lesions lasting a few days, but a bulla is greater than 1cm in diameter while a vesicle is les than 1 cm in diameter.

Question 10

Psoriasis often presents in a symmetrical distribution and most commonly involves the scalp and extensor aspects of the elbows and knees. Where else can be involved?

Answer 10

Gluteal cleft (buttcrack)
Umbilicus.

Question 11

Does itch accompany psoriasis?

Answer 11

Itch is not normally the PREDOMINANT feature of psoriasis, unlike other conditions such as dermatitis and fungal infections.

Question 12

Does nail involvement accompany first presentation of psoriasis?

Answer 12

Nail involvement in the form of pitting and onycholysis (separation of the nail plate from the nail bed) is often seen and can involve one of more of the nails. This is normally observed in patients with longstanding psoriasis and is therefore of little value in patients presenting with rash of recent onset.

Question 13

What is pustular psoriasis?

Answer 13

In this rare form of psoriasis sterile pustules are an obvious clinical feature. The pustules tend to be located on the advancing edge of the lesions and typically occur on the palms of the hands and soles of the feet.

Question 14

Where does pustular psoriasis tend to occur?

Answer 14

In this rare form of psoriasis sterile pustules are an obvious clinical feature. The pustules tend to be located on the advancing edge of the lesions and typically occur on the palms of the hands and soles of the feet.

Question 15

Seborrhoeic psoriasis is also known as:

Answer 15

Flexural psoriasis.

Question 16

What is seborrhoeic psoriasis?

Answer 16

Refers to classic lesions that affect the scalp but with less typical lesions (lack scaling) in the body folds, especially the groins and axillae.

Often, in mild cases the scalp might be the only part of the body involved.

Itch, in this form, can be prominent.

Question 17

Itch can be a prominent feature of which type of psoriasis?

Answer 17

Seborrhoeic psoriasis.

Refers to classic lesions that affect the scalp but with less typical lesions (lack scaling) in the body folds, especially the groins and axillae.

Often, in mild cases the scalp might be the only part of the body involved.

Itch, in this form, can be prominent.

Question 18

What is guttate psoriasis also known as?

Answer 18

Raindrop psoriasis.

Question 19

What is guttate psoriasis/raindrop psoriasis?

Answer 19

Type of psoriasis characterised by crops of scattered small lesions (less than 1cm) covered with light flaky scales that often affects the trunk and proximal part of the limbs.

This form of psoriasis usually occurs in adolescents and often follows a streptococall throat infection and in people genetically predisposed to psoriasis.

Question 20

What form of psoriasis usually occurs in adolescents and often follows a streptococcal throat infection in people genetically predisposed to psoriasis?

Answer 20

Guttate psoriasis/raindrop psoriasis.

Type of psoriasis characterised by crops of scattered small lesions (less than 1cm) covered with light flaky scales that often affects the trunk and proximal part of the limbs.

Question 21

What is lichen planus?

Answer 21

Uncommon condition and is reported to only account for 0.2-0.8% of dermatological outpatient consultations. The lesions are similar in apperance to plaque psoriasis but are itchy and are normally located on the inner surfaces of the wrists and on the shins, an atypical distribution for psoriasis. Additionally, oral mucous membranes are normaly affected with white, slightly raised lesions that look a little like a spider’s web.

Question 22

Lesions that are similar in appeance to plaque psoriasis but are itchy and are normally located on the inner surfaces of the wrists and on the shins, an atypical distribution for psoriasis is what?

Answer 22

Lichen planus

Question 23

What is pityriasis rosea characterised by?

Answer 23

Erythematous scaling mainly on the trunk, but also on the thighs and upper arms.

The colour of the rash tends to be lighter pink colour than psoriasis and can be midly itchy.

A ‘target’ disc lesion, often misdiagnosed as ringworm, is followed 1 week later with an extensive rash.

The condition usually remits spontaneously after 4 to 8 weeks. An accurate history will normally eliminate pityriasis rosea from psoriasis, as the condition is acute in onset and the patient can often identify the initial ‘target’ lesion.

Question 24

What medicines can worsen or aggravate existing psoriasis?

Answer 24

1. lithium
2. Antimalarials
3. Beta-blockers

Question 25

Can digoxin worsen psoriasis?

Answer 25

Yes

Question 26

Can amiodarone worsen psoriasis?

Answer 26

Yes

Question 27

Can clonidine worsen psoriasis?

Answer 27

Yes

Question 28

Can penicillin worsen psoriasis?

Answer 28

Yes

Question 29

What are the trigger points for referral with psoriasis? (3)

Answer 29

1. Lesions that are extensive, follow recent infection or case moderate to severe itching.
2. Patients with psoriatic-type lesions but who have no family history or past personal history of psoriasis.
3. Pustular psoriatic lesions.

Question 30

How are emollients used in psoriasis?

Answer 30

They are frequently prescribed and used to help soften scaling and soothe the skin so redcing irritation, cracking and dryness.

Question 31

Keratolytics, such as _______ ____ and ______ ____ have been incorporated into emolients to aid clearing scale and are often used for scalp psoriasis where very thick scaling can occur.

Answer 31

salicylic acid and lactic acid.

Question 32

Alphosyl contains

Answer 32

Coal tar

Question 33

Psorin contains

Answer 33

Dithranol

Question 34

What are the problems with tar and dithranol products?

Answer 34

Coal rar and dithranol share common problems of patient compliance. Both are messy to use, have an unpleasant odour and can stain skin and clothing.

Question 35

Does UV light help with psoriasis?

Answer 35

90% of patients with psoriasis improve when they are exposed to sunlight and most patients notice an improvement when they go on holiday.

Question 36

What is the active of Dovonex?

Answer 36

Calcipotriol

Question 37

What potency is clobetasone?

Answer 37

Moderate

Question 38

What potency is clobetasol?

Answer 38

Very potent

Question 39

What potency is hydrocortisone butyrate?

Answer 39

Potent

Question 40

What potency is betamethasome dipropionate 0.05%?

Answer 40

Potent

Question 41

What potency is beclometasone?

Answer 41

Potent