Ezcema Flashcards
What percentage of children will be diagnosed with eczema at somepoint in childhood?
24%
Is the prevalence of eczema increasing or decreasing?
Increasing, currently at 4%
What is eczema also known as?
Dermatitis
What is eczema?
Eczema is a condition where patches of skin become inflamed, itchy, red, cracked, and rough. Blisters may sometimes occur.
Is an inflammatory skin condition
What parts of the body does eczema often impact?
Flexural areas
What does eczema lead to generally?
It is irritated skin that leads to barrier dysfunction and inflammation
What is 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
- History in 1st degree relative if under 4 years old
What is the pathogenesis of atopic eczema?
Genetics:
- Many genes implicated
- Role for filaggrin gene
- Atopic family history
- Atopic eczema, asthma hay fever (allergic rhinitis), food allergy
Epidermal barrier dysfunction
Environmental factors
Immune system dysregulation
What gene is involved in the development of atopic eczema?
Filaggrin gene
What is the pathology of atopic eczema?
Spongiosis (intercellular oedema) within the epidermis
Acanthosis (thickening of the epidermis)
Inflammation, superficial perivascular lymphohistiocystic infiltrate
The epidermis is the outermost layer of skin, the dermis contains blood vessels, lymph vessels, hair follicles and sweat glands
What is spongiosis?
Intercellular oedema
What is acanthosis?
Thickening of the epidermis
What is the pathology of acute dermatitis?
- Intercellular oedema within the epidermis
- Can lead to accumulation of intra-epidermal vesicles
- Infiltration of the epidermis with lymphocytes is common
- Dermal changes include varying degrees of oedema and a superficial perivascular infiltrate with lymphocytes, histiocytes and occasional neutrophils and eosinophils

What is the pathology of chronic (spongiotic) dermatitis?
- Degree of spongiosis is often mild
- Significant epidermal acanthosis (thickening of epidermis)
- Fibrosis of papillary dermis may be present

What are the clinical features of atopic eczema?
- 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
What is the distribution of atopic eczema?
- Flexures, neck, eyelids, face, hands and feet
- Tends to spare nappy area
Other than atopic eczema, what are some other types of eczema?
Exogenous (external):
- Contact dermatitis
- Irritant
- Allergic
- Lichen simplex
- Photoallergic or photoaggravated eczema
Endogenous (internal):
- Atopic
- Discoid
- Venous
- Seborrhoeic dermatitis
- Pompholyx
- Juvenile plantar dermatitis
What is allergic contact dermatitis?
Type 4 hypersensitivity:
- Delayed hypersensitivity can take 48-72 hours to develop reaction
- Antigen presenting cells take hapten/allergen to LN and present to naïve T cells
- Clonal expansion of T cells, released into blood stream
- When these T cells next encounter hapten
- Mast cell degranulation, vasodilation and neutrophils
What is hapten?
A small molecule which, when combined with a larger carrier such as a protein, can elicit the production of antibodies which bind specifically to it (in the free or combined state)
What kind of hypersensitivity reaction is allergic contact dermatitis?
Type 4
What is irritant contact dermatitis?
Form of contact dermatitis, in which the skin is injured by friction, environmental factors such as cold, over-exposure to water, or chemicals such as acids, alkalis, detergents and solvents
What can the skin be injured by to cause irritant contact dermatitis?
Skin injured by:
- Friction
- Micro-trauma, cumulative
- Environmental factors
- Cold
- Over-exposure to water
- Chemicals such as acids, alkalis, detergents and solvents
What is a major risk factor for irritant contact dermatitis?
Occupation puts people at risk:
- Hairdressers
- NHS staff
- Cleaners
- Dermatitis
- Nappy rash
What investigation should be done with irritant contact dermatitis?
Patch testing:
- Finds out whether or not skin condition is caused or aggravated by an allergy
- Potential allergen is applied
What is deborrhoeic dermatitis?
A common, chronic or relapsing form of eczema/dermatitis that mainly affects the sebaceous, gland-rich regions of the scalp, face, and trunk .
What is the clinical presentation presentation of seborrhoeic dermatitis in infants?
Distinctive pattern
Predelection for scalp, proximal flexures
<6 months age usually
Often clears within weeks without treatment
Is seborrhoeic eczema chronic or acute?
Chronic dermatitis
What is the clinical presentation of seborrhoeic eczema?
- Red, sharply marinated lesions covered with greasy looking scales
- Distinctive distribution, areas rich in supply of sebaceous glands (scalp, face, upper trunk)
What yeast is increased in seborrhoeic eczema in adults?
Malassezia yeast
What is the treatment of seborrhoeic eczema for adults?
Treat with topical anti-yeast (ketoconazole)
If severe, consider HIV test
What is discoid eczema?
Circular plaques of eczema
Cause is often unknown
Where does discoid eczema often develop?
Sites of trauma/irritation
What is pompholyx eczema?
Type of eczema that causes tiny blisters to develop across the fingers, palms of the hands and sometimes the soles of the feet
What is vesicular eczema?
form of hand eczema characterised by vesicles or bullae (blisters)
Where does pomphyloyx eczema affect?
Palms of hands, sometimes soles of feet
Where does vesicular eczema affect?
Palms of hands
In what age group is pompholyx/vesicular eczema most common?
<40 years
What is asteatotic eczema?
Very dry skin
What are risk factors for asteototic eczema?
Hot climate
Excessive washing/soaps
What is the clinical presentation of asteatotic eczema?
Cracked scaly apeparance
Most commonly shins affected
What is venous eczema also known as?
Stasis eczema or varicose eczema
What is the clinical presentation of venous eczema?
- Increased venous pressure
- Oedema
- Ankle and lower leg involved
What is the treatment of venous eczema?
Resolution of oedema can help – compression stockings
What is venous eczema?
Long-term skin condition that affects the lower legs. It’s common in people with varicose veins
What is eczema herpeticum?
Disseminated viral infection
What is the clinical presentation of eczema herpeticum?
- Fever and often unwell
- Itchy clusters of blisters and erosions
- Swollen lymph glands
What is eczema herpeticum caused by?
Herpes simplex 1 and 2
What is the treatment of eczema herpeticum?
- Admission
- Antivirals
- Consider secondary bacterial infection
What is the treatment of eczema?
- Patient education
- Avoid causative/exacerbating factors
- Emollients (moisturisers)
- Ointment, greasy but effective
- Creams, lighter
- Lotions, more watery
- Soap substitutes
- Intermittent topical steroids
- Different potency
- Hydrocortisone (low)
- Betamethasone (potent)
- Sometimes need antihistamines or antimicrobials
- Calcineurin inhibitors
- Topical pimecrolimus and tacrolimus
What is the treatment of severe eczema?
- UV light
- Immunosuppresion
- Azathioprine
- Ciclosporin
- Mycophenolate mofetil
- Methotrexate
What immunosuppression drugs can be used to treat severe eczema?
- Azathioprine
- Ciclosporin
- Mycophenolate mofetil
- Methotrexate
What are different kinds of emollients that can be used for eczema?
- Ointment, greasy but effective
- Creams, lighter
- Lotions, more watery
What are emollients?
Moisturisers
What are some intermittent topical steroids for eczema?
- Different potency
- Hydrocortisone (low)
- Betamethasone (potent)
What are some future treatments for eczema?
Crisaborole:
- Topical PDE-4 inhibitor
- FDA approved
Dupilumab:
- 1st biologic for eczema patients
- IL-4/IL-13 inhibitor
What is crisaborole?
Topical PDE-4 inhibitor
What is dupilumab?
- 1st biologic for eczema patients
- IL-4/IL-13 inhibitor