Eczema ☺️ Flashcards
Description
Atopic eczema/dermatitis is a condition that causes the skin to become itchy, dry and cracked
Aetiology
Often has specific triggers
- soaps, detergents
- synthetic, wool, silk fabric
- stress
- seasonal variation => increased sweat
- hormonal triggers
- diet => itch, redness immediately or hours after common allergens
- skin infection
- hayfever, allergies
Epidemiology
More common in children, often developing before the age of 1
Can develop it in adulthood
Normally a chronic condition but it can improve and clear with age
Pathophysiology
Type 1 hypersensitivity
- antigen processed by APC => presented to Th2
- Th2 releases cytokines to stimulate IgE release from Bcells
- IgE binds to mast cells, when they bind to allergens => granules of histamine released
Type 4 sensitivity
- antigen processed by APC => presented to lymphocytes
- lymphocyte proliferation => inflammatory cytokine release
- leads to skin symptoms
Symptoms
Intense itchy, dry, cracked and sore
Can be small patches or be widespread
Inflammed pale skin => red
Inflammed darker skin => darker brown
Flexor surfaces
Face, scalp
Flareups
Associated with FHx, atopic triad
Signs
Visible flexural eczema involving skin creases
Cheeks, extensor surfaces of young children
Acute => variable, poor demarcated redness, vesicles, scales, crusts
Chronic => lichenified from repeated scratching
Raised dry well demarcated scaly patches
Differential diagnoses
AI
-psoriasis => generally doesn’t appear until later in life on extensor surfaces, thicker, painful silvery and more scaly. INTENSE ITCH
Infective/inflammatory
- fungal infection => annular patch or plaque with scaly border and central clearing
- scabies => recent onset of itchy rash in family particularly at night
- seborrhaic dermatitis => associated with areas rich in sebaceous glands
Environmental
-contact dermatitis => can be a differential and a trigger of atopic
Investigations
Not required to establish a diagnosis but can be useful to exclude other differentials especially if they do not respond to treatment
Patch allergy testing => identify triggers
Repeated open application test => 1wk with suspected causative agent on unaffected area for contact dermatitis
Ectoparasite preparation => high suspicion of scabies
Management - acute flares (pharmacological)
Emollients => decrease dryness, improve barrier function of skin and symptoms
-may have to try different types
May consider intermittent topical CS
-hydrocortisone to reduce inflammation and itch
If there is evidence of cutaneous infection, add ABx
Management - chronic flares (pharmacological)
Same as acute but may consider calcineurin inhibitors (inhibit T cell activation
Management - self care and advice
Explain that eczema is a chronic illness with flares but can be controlled with appropriate treatment
- frequent and liberal use of emollients even when skin is clear
- avoid triggers and scratching
Info of eczema support
-British Association of Dermatologists, National Eczema Society
Complications
Prognosis
Infection
-staph aureus => impetigo or worsening of eczema
-herpes simplex => eczema herpeticum (grouped vesicles, punched out erosions can bleed and extend over body with systematic symptoms)
MEDICAL EMERGENCY DUE TO POSSIBLE EYE AND MENINGEAL INVOLVEMENT
-superficial fungal infections
Psychosocial problems
- distress, depression
- higher rates of behavioural problems, fearfullness, dependencey on parents in nursery
- time out of school from bullying, social restrictions, impaired peformance
- poor self image, confidence => impacts on social development
- sleep disturbances due to itch
