Psoriasis Flashcards
What is psoriasis?
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.
What is the commonest form of psoriasis?
Plaque psoriasis.
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
50-60%
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?
Streptococcal.
What are the only forms of psoriasis that can be managed by a community pharmacist?
Scalp and plaque.
The typical distribution of psoriatic plaques is what? (5)
Scalp/head (not face) Elbows. Knees. Buttcrack. Groin.
Plaque psoriasis classically presents with characteristic salmon-pink lesions with what colour scales and what form of boundaries?
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.
What is a comedone?
A papule which is ‘plugged’ with keratin and sebum.
What is the difference between a bulla and a vesicle?
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.
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?
Gluteal cleft (buttcrack) Umbilicus.
Does itch accompany psoriasis?
Itch is not normally the PREDOMINANT feature of psoriasis, unlike other conditions such as dermatitis and fungal infections.
Does nail involvement accompany first presentation of psoriasis?
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.
What is pustular psoriasis?
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.
Where does pustular psoriasis tend to occur?
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.
Seborrhoeic psoriasis is also known as:
Flexural psoriasis.
What is 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.
Itch can be a prominent feature of which type of psoriasis?
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.
What is guttate psoriasis also known as?
Raindrop psoriasis.
What is 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.
This form of psoriasis usually occurs in adolescents and often follows a streptococall throat infection and in people genetically predisposed to psoriasis.
What form of psoriasis usually occurs in adolescents and often follows a streptococcal throat infection in people genetically predisposed to psoriasis?
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.
What is lichen planus?
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.
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?
Lichen planus
What is pityriasis rosea characterised by?
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.
What medicines can worsen or aggravate existing psoriasis?
- lithium
- Antimalarials
- Beta-blockers