Psoriasis Flashcards by Caitlin McMullen

What is Psoriasis?

Common chronic inflammatory dermatosis - extensors

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What genetic factors are associated with psoriasis?

HLA types and the PSORS1 gene

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Erythematous meaning

redness of the skin

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At what ages does psoriasis commonly peak in incidence?

2 peaks in incidence—
(1) one in the 20s
(2) another in the 50s

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What are some common triggers of psoriasis?

(1) Stress
(2) Trauma
(3) Alcohol
(4) Smoking
(5) Infections
(especially streptococcal throat infections)

(6) Certain medications
(eg, β-blockers, lithium, antimalarials, rapid withdrawal of steroids)

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What is the underlying mechanism of psoriasis?

Psoriasis is caused by hyperproliferation of epidermal cells, leading to excessive keratinocyte turnover and inflammation

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What is the Koebner phenomenon?

It refers to the appearance of psoriasis
(1) lesions at sites of trauma
(2) such as cuts, burns, or surgical wounds

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How does chronic plaque psoriasis typically present?

(1) Symmetrical
(2) Red
(3) Scaly plaques
(4) Well-defined edges
(5) Commonly found on extensor surfaces
= elbows, knees, scalp, and lower back

(6) The scales are typically silvery-white
(7) Thick

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What are the key nail changes seen in psoriasis?

Nail pitting
Onycholysis
(nail lifting from the nail bed)
Subungual hyperkeratosis (thickening of the nail bed).

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What is Auspitz’s sign?

Pinpoint bleeding when the surface scale is removed from a psoriasis plaque

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What is guttate psoriasis, and what commonly triggers it?

Guttate psoriasis presents as
(1) Multiple small
(2) Raindrop-shaped
(3) Erythematous plaques
(4) Often following a streptococcal throat infection in young adults

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How does flexural (inverse) psoriasis differ from chronic plaque psoriasis?

Flexural psoriasis appears as
(1) Smooth
(2) Red
(3) Non-scaly plaques
(4) In skin folds
(eg, groin, under breasts)

(5) Often colonised by Candida yeast
(6) Shiny

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What are the key features of pustular psoriasis?

Pustular psoriasis presents with
(1) Sterile pustules and petechiae
(2) Often on the palms and soles
(3) Can be associated with systemic inflammation (leukocytosis, fever)

(4) White pustules on red skin

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When is a biopsy needed for psoriasis?

Rarely, but it may be performed to rule out other conditions

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What is erythrodermic psoriasis, and why is it serious?

A rare but severe form of psoriasis characterised by
(1) Widespread erythroderma
= red, inflamed, peeling skin

(2) Covers most of the body

Which can lead to life-threatening complications like hypothermia and dehydration

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What histological findings are characteristic of psoriasis?

(1) Thickened epidermis
(2) Parakeratosis
= Dead skin cells don’t fully mature and keep their nuclei

(3) Munro microabscesses
=Small clusters of neutrophils in the outer skin

(4) Elongated rete ridges
= The lower part of the epidermis extends deeper into the dermis

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What is the first-line treatment for mild to moderate psoriasis?

Emollients
(to reduce scaling and itching)
- topical corticosteroids
  (eg, betamethasone 0.1%)
Topical vitamin D analogues
(eg, calcipotriol)

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What treatments are used in secondary care for moderate to severe psoriasis?

Phototherapy
UVB for guttate psoriasis
PUVA for resistant cases
Systemic treatments like methotrexate (immunosuppressive) or biologics

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Why should systemic corticosteroids be avoided in psoriasis?

Rapid withdrawal can cause rebound psoriasis, leading to severe disease flare-ups

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How is scalp psoriasis managed?

Treatment involves use of a potent topical corticosteroid for 4 weeks

Which phenomenon describes the tendency for psoriatic lesions to develop at sites of skin trauma?

Koebner phenomenon

Which type of lymphocytes are seen at elevated levels mainly in the epidermis of individuals with psoriasis?

CD8 positive T cells

How should Seborrheic eczema affecting the scalp be treated?

2% salicylic acid shampoo

Which type of psoriasis most commonly affects young people after a strep infection?

Guttate psoriasis

What is the Koebner phenomenon?

The Koebner phenomenon is where skin lesions occur at sites of skin injury in otherwise healthy skin. It can occur in psoriasis, lichen planus and vitiligo

Which joints are most commonly involved in psoriatic arthritis?

Small joints of the fingers

Which topical corticosteroids are used in psoriasis (in order of increasing potency)?

"Help Every Budding Dermatologist" (1) Mild- Hydrocortisone 0.5% (2) Moderate- Eumovate (clobetasone butyrate 0.05%) (3) Potent- Betnovate (betamethasone valerate 0.1%) (4) Very potent- Dermovate (clobetasol propionate 0.05%)

What are the medical treatment options in psoriasis?

1st = methotrexate 2nd = ciclosporin (1st line if rapid disease control needed/palmoplantar pustulosis/are considering conception) 3rd = acitretin

Which pro-inflammatory cytokine has elevated levels in psoriasis?

TNF

A 32-year-old man attends the Dermatology clinic with very severe psoriasis over his abdomen, elbows, knees and scalp. He tells you that it has been getting worse over the last few months and the normal treatment he uses, topical steroids, is no longer effective. You decide that he is now suitable for systemic therapy. What is the mechanism of action of the medication they will be started on?

Anti-folate = Drug is Methotrexate

A 54-year-old male presents to his GP because of an itchy scalp which has been progressing for six months. He has also noticed that his scalp has started to scale. He has recently been started on propranolol for hypertension. When you ask about his mood, he says that he has been particularly stressed at work. Recently, he went on holiday to Spain to try de-stressing. Unfortunately, this did not help his mood, although his skin did improve. What is the most likely diagnosis? and how do you know this?

Psoriasis = indicated by an itchy scalp, which is starting to scale. Psoriasis is exacerbated by beta-blockers, stress, and relieved by exposure to the sun

A 54 year old woman with plaque psoriasis attends the GP for follow up. She has been using a topical potent corticosteroid, a vitamin D analogue once daily, and regular emollients. Despite this, her plaques are still bothering her and are not improving. What is the most appropriate next step?

Use vitamin D analogue twice daily

What is the complete management for psoriasis?

Emollient - All patients 1. Potent topical steroid + topical vitamin D 2. Vitamin D alone (twice daily) 3. Steroid alone (twice daily) 4. Phototherapy - if persistent 5. Methotrexate - in severe cases

An 18-year-old man presents to his GP with a rash on his legs, 2 weeks after receiving antibiotics for a sore throat. On examination, he has multiple "drop-shaped" erythematous plaques on both legs. What is the most appropriate treatment for this rash? and what is this type of psoriasis, and how can you tell?

Prescribe a topical emollient = This patient has guttate psoriasis, which appears as (1) multiple small (2) tear-drop-shaped (3) erythematous plaques (4) on the trunk and legs (5) after a Streptococcal infection in young adults. It is usually self-limiting, so reassurance plus or minus a topical emollient is the advised treatment

A 30-year-old male presents to his GP with erythematous plaques covering his elbows and knees. The lesions have been gradually worsening over the past few months and are mildly itchy. On examination, Auspitz sign is present upon removal of the plaques. What is the most appropriate first line management for the likely diagnosis?

Topical Potent Corticosteroid + Topical Vitamin D Preparation 0.1% Betamethasone + Calcipotriol

A 16-year-old female has presented to her GP with a new rash which appeared suddenly. On examination the rash is on her torso and lower back and consists of multiple small, monomorphic, scaly, red, 'drop' shaped lesions. She reports having a sore throat two weeks previously What is the most likely diagnosis and how can you tell?

Guttate Psoriasis = type of Psoriasis that is typically triggered by a Streptococcal infection. The rash has a sudden onset 2-4 weeks post infection. It most commonly occurs in children and young adults

What are the side effects of ciclosporin?

5 H’s (1) hypertrophy of the gums (2) hypertrichosis (3) hypertension (4) hyperkalaemia (5) hyperglycaemia (diabetes)

A 32-year-old man presents to his GP with a dry scaly rash in his hair. He says it has been there since he had the flu one month previously. He reports that his mother and sister sometimes have a similar rash but it does not involve their scalp. Given the most likely diagnosis, which of the following are areas where this rash would also often appear?

Extensor surfaces of elbows and knees

A 33-year-old woman is referred to the Dermatology clinic for suspected psoriasis. The Dermatologist diagnoses chronic plaque psoriasis and commences the patient on a topical steroids. What is an example of a potent topical steroid?

Betnovate (0.1% Betamethasone) (potent topical steroid) = first line for chronic plaque psoriasis

A 14-year-old boy has presented to the GP with his father. His father reports his son accidentally cut himself on his elbow with a kitchen knife a few weeks ago. He has now developed a new rash forming where the skin is healing. Which skin condition can behave in this way? And what does this describe?

Psoriasis = This case describes the Koebner phenomenon, which is the presence of a new skin lesion on previously healthy skin following injury

A patient with psoriasis gets a scratch on their arm, and new plaques form along the scratch line. What is this describing?

Koebner phenomenon

What is the location of chronic Plaque (Vulgaris)?

Extensors = elbows, knees, scalp, lower back

Smooth, red, shiny plaques (minimal scaling) This is describing what type of psoriasis?

Inverse (Flexural)

What is the most common type of psoriasis?

Chronic Plaque (Vulgaris) = symmetrical

What psoriasis types need more than just topical treatments?

1. Pustular psoriasis = methotrexate 2. Erythrodermic psoriasis = hospital

Psoriasis is mediated by what cells

Type 1 helper T cells - CD8

A 65-year-old man presents to the dermatology clinic with an itchy rash over his scalp and behind his ears. On examination, the doctor also notices similar lesions in a linear distribution on the lateral thigh of the left leg. The patient states that he had a recent left hip replacement, and the lesions developed over the scar two weeks later. Where in this suggest koebner phenomenon

hip replacement, scar

A 42-year-old man is reviewed by his dermatologist for ongoing psoriasis. He was diagnosed several years ago and has had recurrent bouts since then. Recently, he has just completed a 4-week course of topical betamethasone and calcipotriol to bring the latest flare-up under control. Given the frequency of flare-ups, the dermatologist suggests starting a long-term regime to keep his psoriasis under control. What would be suitable long-term?

Vitamin D analogue - Calcipotrio

When and only when is emollients first line

red, dry rashes usually presenting on the flexor aspects of joints - mild