Eczema: Atopic dermatitis Flashcards
Dermatology
Define eczema?
Chronic condition that causes skin itchiness, inflammation, irritation
Why is eczema used interchangeably with the term dermatitis?
Eczema is a form of chronic dermatitis
Dermatitis: Conditions that cause skin inflammation
What are the 9 main types of eczema?
Pompholyx
Contact dermatitis
Atopic dermatitis
Venous eczema
Lichen simplex
Gravitational eczema
Irritant dermatitis
Discoid eczema
Seborrheic dermatitis
What is pompholyx?
Eczema that affects hands and feet
What is allergic contact dermatitis?
Eczema caused by contact with allergen
What is irritant contact dermatitis?
Eczema caused by non-specific response contact with physical or chemical irritant
What is the most common form of eczema?
Atopic dermatitis
What is the typical onset age of atopic dermatitis?
Childhood (before 5 yrs old) but can occur at any age
What kind of conditions are usually associated with atopic dermatitis?
Other atopic conditions eg. asthma, hay fever
What kind of history does a patient with atopic dermatitis usually present with?
Family history of atopy
How does presentation of atopic dermatitis typically change with age?
Affects more flexural surfaces, less extensor surfaces
As age increases
What 3 types of skin abnormalities does atopic dermatitis commonly present as?
Plaques
Patches
Papules
Describe how plaques, patches or papules caused by atopic dermatitis typically present?
Pruritic (incessant and causes poor sleep)
Erythematous
Flaky, crusty, dry (xerosis)
What is the typical distribution of atopic dermatitis in infants?
Face, scalp, neck, trunk and extensor surfaces
What is the typical distribution of atopic dermatitis in children?
Flexor surfaces with residue on face, neck
What is the typical distribution of atopic dermatitis in adults?
Flexor surfaces
How is the diagnosis of atopic dermatitis confirmed?
Clinical diagnosis confirmed by patient history (particularly family history)
What FBC finding can indicate atopic dermatitis?
Elevated eosinophil count
What is xerosis?
Dry, flaky skin
How can you investigate if eczema is causing infection?
Skin swab to confirm if a viral or bacterial infection has caused it, can also guide treatment
Why can a patch test be useful in diagnosing eczema?
Patch test to confirm if a particular substance/allergen is causing it
Give 2 examples of scoring tools used to measure the severity of eczema?
Eczema Area and Severity Index (EASI)
Dermatology Life Quality Index (DLQI)
What types of emollients are used to treat atopic dermatitis?
Lotion, cream, ointments
Which 4 topical steroids are used to treat atopic dermatitis?
1% hydrocortisone cream: Mildly potent so is used for infants with face, mild eczema and eyelids
Eumovate cream: Mild-moderately potent so is used for infants with body eczema, face
Elocon 0.1% cream: Moderately potent so is used for body
Dermovate cream: Very potent so is used for severe body eczema
How does a patient measure how much topical steroid to used for eczema?
Finger Tip Unit (FTU): (about 500mg) is the amount needed to squeeze a line from the tip of an adult finger to the first crease of the finger
Various estimates for body surface area and the number of FTUs required
How often should a patient use topical steroid to treat eczema?
Daily use for 2-4 weeks then reduce to alternate days, then to 1/2 times weekly
When are topical calcineurin inhibitors indicated for treatment of eczema?
Alternative to topical steroids
How old must patients be for licensed use of topical calcineurin inhibitors, to treat eczema?
2 yrs old and older
What is the most important side effect of oral calcineurin inhibitors for treatment of eczema?
Increase risk of lymphoma/skin malignancy
When is phototherapy indicated for treatment of eczema?
Moderate-severe eczema that won’t respond to topical treatments alone
What kind of phototherapy is used for body eczema?
UVB
What kind of phototherapy is used for hands and feet eczema?
PUVA (psoralen and ultraviolet A)
How often does a patient receive phototherapy to treat eczema?
Several appointments at hospital per week, for a few weeks
Give 2 examples of biologics that can be used to treat eczema?
Monoclonal antibodies
JAK inhibitors
Can DMARDs be used to treat eczema?
Yes
What are the 3 main factors that make up the pathophysiology of eczema?
Genetic
Environmental
Immunological
What is the correlation between individuals with atopic dermatitis and infections?
Individuals with AD more likely to develop viral, bacterial, fungal infections
What is the genetic factor that causes epidermal dysfunction and leads to eczema?
Mutation causing filaggrin deficiency (faulty epithelial differentiation genes on chromosome 1), which bind keratin in the epidermis
Which 2 epidermal layers are most affected by eczema?
Stratum granulosum: Comprises keratinocytes that have matured to the point where they are beginning to produce the large amounts of keratin
Stratum corneum: Contains keratinocytes that are shedding keratin
What do epithelial differentiation genes code for, and how can mutations cause eczema?
Code for lipids, enzymes, proteins (eg. filaggrin) to provide stability to epidermis
Unstable structure which allows penetration of allergens and microbes
What causes dry skin in eczema?
Less natural moisture in skin due to reduced lipids
What mechanical stress can contribute to eczema?
Itching skin
What is the combined result of mechanical stress, unstable epidermal structure and penetration of irritants on eczema?
Weakens epidermal barrier more, exacerbates eczema
What is excoriation?
Uncontrollable skin-picking which can cause irritation and scarring
What is lichenification?
Thick leathery skin with exaggerated skin markings caused by sudden itching
