Eczema Flashcards
How common is eczema in children?
It’s common
24% of children will be diagnosed with eczema at some point in their childhood
What is atopic eczema?
Also known as atopic dermatitis
Inflammatory skin condition.
Commonly affects flexural areas.
Multiple types and a spectrum of severity
Wide range of external (exogenous) or internal (endogenous) factors can induce the condition.
Barrier dysfunction + inflammation
Definition of atopic eczema- Diagnostic Criteria
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 History in 1st degree relative if under 4 yrs
Pathogenesis of Atopic Eczema
Genetics Many genes implicated Key role for Filaggrin gene Atopic family history atopic eczema, asthma hay fever (allergic rhinitis), food allergy Epidermal barrier dysfunction Environmental factors Immune system dysregulation
Atopic Eczema Histopathology
Spongiosis (intercellular oedema) within the epidermis
Acanthosis (thickening of the epidermis)
Inflammation Superficial
–> perivascular lymphohistiocytic infiltrate.
Clinically presenting features of atopic eczema
General/distribution:
Acute:
Chronic:
Itch!!
Distribution
Flexures, Neck, Eyelids, Face, Hands and feet
Tends to spare nappy area
Acute changes
Pruritus, Erythema, Scale, Papules, Vesicles, Exudate,Crusting, Excoriation
Chronic changes
Lichenification, Plaques, Fissuring
Affected areas of atopic eczema in CHILDREN UNDER 2 Yrs
CHEEKS
LINES UNDER EYES
ATOPIC ECZEMA
Affected areas
FLEXURES
Other types of Eczema
Endogenous (internal)
Exogenous (external)
Endogenous Eczema (internal)
Endogenous (internal) Atopic Discoid Venous Seborrhoeic dermatitis Pompholyx Juvenile plantar dermatitis Asteatotic
Exogenous Eczema (external)
Exogenous (external) Contact dermatitis Irritant Allergic Lichen simplex Photoallergic or photoaggravated eczema (UV/visible light)
Allergic contact dermatitis
Type 4 Hypersensitivity
Delayed hypersensitivity – can take 48-72 hrs to develop reaction
Antigen presenting cells take hapten/ allergen to LN and present to naive T cells
Clonal expansion of these T cells, released into blood stream
When these T cells next encounter hapten
Mast cell degranulation
vasodilatation
neutrophil aggregation
Irritant contact dermatitis
Skin injured by……
Skin injured by……
1) Friction – micro-trauma, cumulative
2) Environmental factors
cold
over-exposure to water
chemicals such as acids, alkalis, detergents and solvents
Occupation Hairdressers NHS staff Cleaners Dermatitis – under a ring on finger – soaps can accumulate –irritant Nappy rash
Investigation for suspected Eczema
Patch testing
Describe Patch testing
Potential allergens applied (no needles involved!)
Baseline/standard series – applied to all patients
Apply Monday
Remove Wednesday
Re-assess Friday
Seborrhoeic dermatitis - Infants
Distinctive pattern
Predilection for scalp, proximal flexures.
<6months age usually.
Clears within weeks of treatment
Seborrhoeic eczema - adults
Chronic dermatitis.
Malassezia yeast increased in the scaly epidermis of dandruff and seborrehoic dermatitis.
Red, sharply marginated lesions covered with greasy looking scales
Distinctive distribution – areas rich in supply of sebaceous glands (scalp, face, upper trunk).
Seborrhoeic eczema
Precursor
Dandruff can be a pre-cursor. May gradually progress through redness irritation increased scaling
Seborrhoeic eczema
Treatment
Treat with TOPICAL ANTI-YEAST:(Ketoconazole)
If severe, consider HIV test – immunocompromised?
Discoid eczema
Circular plaques of eczema.
Cause often unknown.
May develop at sites of trauma/irritation
POMPHOLYX
VESICULAR
|eczema
Palms and soles. Intensely itchy! More common under 40 years. Sudden onset of crops of vesicles. Resolution can include desquamation.
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 and lower leg involved. Resolution of oedema can help:– compression stockings.
Eczema Herpeticum
Disseminated viral infection Fever and often unwell Itchy clusters of blisters and erosions Herpes Simplex 1 and 2 Swollen lymph glands
Consider:admission, antivirals, secondary bacterial infection.
