Psoriasis

Question 1

What is psoriasis?

Answer 1

Chronic, genetically determined, immune-mediated, inflammatory skin condition.

Usually characterized by well defined, red, scaly, plaques. Often symmetrical.

It can also involve nails, hair/scalp and joints.

Question 2

What causes psoriasis?

Answer 2

Overactivity of the immune system. Excessive production of TH1 Cytokines inc TNF-alpha (amplify inflammatory cascade). Vascular proliferation (erythema), increased cell turnover (plaques and scaling).

Genetics
Environmental
Infection - Strep, Candida
Drugs - Lithium, Beta-blockers, NSAIDS, Steroid withdrawal
Trauma – Koebner phenomenon (spread with trauma)
Sunlight

Question 3

Chronic Plaque Psoriasis

Answer 3

Accounts for almost 90% of psoriasis cases

Severe cases with bigger plaques have stronger impact on psycho-social and cardio-vascular health

Commonly managed with topical treatments in primary care setting

Question 4

Guttate psoriasis

Answer 4

Commonly post-viral infection. Common in children + adolescents

Usually self-limiting

Responds well to phototherapy

May recur in some cases

Question 5

What is Palmo-plantar Psoriasis?

Answer 5

Psoriasis of the palms and soles

Question 6

Clinical features found in the nails in nail psoriasis

Answer 6

Pitting

Onycholysis

Question 7

Flexural / Inverse Psoriasis

Answer 7

Red rash no scale.

Can be triggered or superinfected by localised dermatophyte candida or bacterial infection (these are also differential diagnoses)

Question 8

Pustular psoriasis

Answer 8

Rare and severe form of psoriasis that involves widespread inflammation of the skin and small white or yellow pus-filled blisters or pustules.

Sterile pustules - no infection

Sometimes have systemic symptoms

Question 9

Erythrodermic psoriasis

Answer 9

‘Red man’ syndrome

> 90% of body affected

needs inpatient treatment

Question 10

Name the different types of psoriasis we should know about

Answer 10

Chronic Plaque Psoriasis
Guttate Psoriasis
Palmo-plantar Psoriasis
Flexural / Inverse Psoriasis
Pustular psoriasis
Erythrodermic psoriasis

Question 11

If the psoriasis is found on the scalp or face what is the differential diagnosis

Answer 11

Seborrhoeic dermatitis

Question 12

Histological signs of psoriasis

Answer 12

Hyperkeratosis (thickening of stratum corneum) with parakeratosis
(keratinocytes with nuclei in stratum corneum)

Neutrophils in stratum corneum (munro’s microabcesses)

Hypogranulosis: no granular layer (needed for barrier function)

Psoriasiform hyperplasia: Acanthosis (thickening of squamous cell layer) with elongated rete ridges

Dilated dermal capillaries

Perivascular lymphohistiocytic infiltrate; T cell infiltration

Question 13

Primary care - initial treatment of psoriasis

Answer 13

Emollients - provide barrier

Vit D3 analogue +/- topical steroids

Tar creams

Topical steroids

Salicylic acid

Question 14

Secondary care treatment of psoriasis

Answer 14

UVB Phototherapy – light treatment – guttate

Oral retinoid: Acitretin ( Teratogenic, Impairment of LFTs/ Lipids)

Immunosuppression - methotrexate, cyclosporin

Biologics - All act on messengers in process of psoriasis development

Question 15

Types of biologics available

Answer 15

Anti-TNF: Etanercept, Infliximab, Adalimumab

IL-12,23 inhib: Ustekinumab

IL 17 inhib: Ixekizumab, Secukinumab

Pt can form antibodies to biologics

Question 16

Treatment of Erythrodermic Psoriasis (emergency)

Answer 16

Recognise 
Admit
FLUID BALANCE
Bloods / IV access
Cover in thick greasy ointment emollients – most important – acts like a barrier

?Systemic, ?biologic treatment
?Trigger

Question 17

What tools can be used to monitor the progress of psoriasis?

Answer 17

Psoriasis Area Severity Index (PASI) - how bad it is - (Body area, redness, thickness, scaliness)

Dermatology Life Quality Index (DLQI) - how much does it bother the patient

Question 18

Associated conditions with psoriasis

Answer 18

Associated with cardiovascular disease, smoking, alcohol, the metabolic syndrome, lymphoma, depression, suicide, potentially harmful drug and light therapies, and possibly melanoma and non-melanoma skin cancers.