Eczema Flashcards
(24 cards)
What is eczema?
Common inflammatory skin condition
Commonly affects flexural areas
Multiple types, spectrum of severity
Epidemiology of eczema?
4% in western countries
Most common in babies and children
~60% cleared by adult life
Definition of atopic eczema?
An itchy skin condition in the last 12 months
Plus 3 of the following:
- Onset before age 2
- History of flexural involvement
- History of generally dry skin
- History of other atopic disease (in 1st degree relative if under 4 yrs)
Pathogenesis of eczema?
Genetics (filaggrin gene) Atopic family history Epidermal barrier dysfunction Environmental factors Immune system dysregulation
Pathology in eczema?
Spongiosis (intercellular oedema within the epidermis)
Acanthosis (thickening of the epidermis)
Inflammation (superficial lymphohistiocytic infiltrate)
Clinical features of eczema?
Itch
Flexures, neck, eyelids, face hands and feet
Acute changes: pruritus, erythema, scale, papules, vesicles, exudate, crusting, excoriation
Chronic changes: Lichenification, plaques, fissuring
Other categories of eczema?
Exogenous (external) and Endogenous (internal)
Types of exogenous eczema?
Contact dermatitis (irritant or allergic)
Lichen simplex
Photoallergic or photoaggravated
Types of endogenous eczema?
Atopic Discoid Venous Seborrhoeic dermatitis Pompholyx Juvenile plantar dermatitis Asteatotic
Allergic contact dermatitis?
Type 4 hypersensitivity
Delayed
Antigen presents to T cells, clonal expansion and release into bloodstream
Next encounter - mast cell degranulation, vasodilatation and neutrophils
Irritant contact dermatitis?
Skin injured by:
1) Friction
2) environmental factors e.g. cold, over exposure to water, chemicals
Patch testing?
Potential allergens applied
Baseline series applied
Applied Monday
Remove Wednesday
Re-assess Friday
Seborrhoeic dermatitis in infants?
Distinctive pattern
Scalp and proximal flexures
Usually <6 months
Often clears within weeks of treatment
Seborrhoeic eczema in adults?
Chronic dermatitis
Malassezia yeast increased in the scaly epidermis
Red, sharply marginated lesions covered with greasy looking scales
Distinctive distribution (areas rich in supply of sebaceous glands)
If severe consider HIV test
Treatment of seborrhoeic eczema?
Ketoconazole (topical anti-yeast)
Discoid eczema?
Circular plaques of eczema
Cause often unknown
May develop at sites of trauma
Pompholyx/vesicular eczema?
Palms and soles
Intensely itchy
More common under 40
Sudden onset of crops of vesicles
Asteatotic eczema?
Very dry skin Cracked scaly appearance Most commonly shins affected Climate - heat Excessive washing/soaps
Venous eczema?
Stasis eczema or varicose eczema Increased venous pressure Oedema Ankle or lower leg Resolution of oedema can help
Eczema herpeticum?
Disseminated viral infection Fever and unwell Itchy clusters of blisters and erosions Herpes simplex 1 and 2 Swollen lymph glands Consider admission, antivirals, consider secondary bacterial infection
Treatment of eczema?
Patient education Avoid causative/exacerbating factors Emollients (ointment>cream>lotion) Soap substitutes Intermittent topical steroids Sometimes antihistamines Calcineurin inhibitors
Treatment of severe eczema?
UV light Immunosuppression - Azathioprine - Cyclosporine - Mycophenolate mofetil - Methotrexate
High potency topical steroid?
Betamethasone
Low potency topical steroid?
Hydrocortisone
