Derm - Eczema & Psoriasis

Question 1

what are the diagnostic criteria for eczema?

Answer 1

Itchy skin condition plus 3+ of the following:

i) Hx of itchiness in skin creases such as folds of elbows, behind knees, fronts of ankles or around neck (or cheeks in <18 mths)
ii) Hx of asthma or hay fever (or Hx of atopic disease in a 1st degree relative in children <4 yrs)
iii) general dry skin in preceding year
iv) visible flexural eczema (or eczema affecting cheeks or forehead and outer limbs in children <4 yrs)
v) onset in 1st 2 yrs of life

Question 2

name examples of trigger factors for eczema flares

Answer 2

Endogenous factors:

• stress
• hormonal changes in women - e.g. pre-menstrual flare-ups, deterioration in pregnancy

Environmental factors:

• irritants, e.g. soaps and detergents
• skin infections - S. aureus (important exacerbating factor)
• contact allergens
• extremes of temp and humidity (usually worse in inter and sweating)
• abrasive fabrics, e.g. wool
• dietary factors (in children)
• inhaled allergens, e.g. house dust mites, pollens, pet dander and moulds

Question 3

which features suggest bacterial infection of eczematous skin?

Answer 3

• weeping, pustules, crusts
• failure to respond to treatment
• rapidly worsening eczema
• fever and malaise

Question 4

describe management of a pt with eczema

Answer 4

1. lifestyle changes: ID and avoid triggers, e.g. avoid soap and detergent, keep skin hydrated, e.g. baths
2. emollients (combination of cream, ointment, bath oil and emollient soap substitute) - apply as liberally and frequently as possible (at least 3-4x/day)
3. topical steroids - if required

Question 5

explain the pathophysiology of chronic plaque psoriasis

Answer 5

Autoimmune condition in which T cells are induced to produce cytokines - stimulate keratinocyte proliferation and production of dermal antigenic molecules.

Question 6

which diseases are frequently associated with psoriasis?

Answer 6

• psoriatic arthritis
• IBD
• metabolic syndrome
• increased risk of CVD, lymphoma and non-melanoma skin cancer

Question 7

name possible risk factors for psoriasis

Answer 7

• FHx/genetics
• lack of sunlight (usually worse in winter)
• infection - Streptococcal or AIDS
• psychological stress
• post-partum hormonal changes
• drugs: lithium, anti-malarials, withdrawal of systemic steroids, B-blockers, ACEi, antibiotics…
• smoking and alcohol
• trauma - can cause spread to uninvolved skin

Question 8

describe common presentation of psoriasis

Answer 8

• itchy plaques (well-demarcated circular/oval red/pink elevated lesions) with overlying white or silvery scale
• distributed symmetrically over extensor body surfaces and scalp
• nail changes: pitting, onycholysis, subungual hyperkeratosis or oil-drop sign

Question 9

describe 1st line management of psoriasis

Answer 9

1. regular emollients (3-4x day): reduce scale and itch
2. topical steroids (max. 2 wks), e.g. beclometasone 0.1%: gain control of disease
3. vitD analogues, usually calcipotriol: for long-term treatment

Question 10

suggest possible treatments that can be initiated in secondary care for severe psoriasis

Answer 10

1. phototherapy
2. methotrexate or ciclosporin
3. biological therapies, e.g. etanercept, infliximab, adalimumab