Dermatology Flashcards
What is atopic eczema (AKA atopic dermatitis)?
A chronic, itchy, inflammatory skin condition that affects people of all ages, although it presents most frequently in childhood
What does the term ‘atopic’ describe?
A group of conditions; eczema, asthma, hay-fever and food allergies, that are linked by an increased activity of the allergy component of the immune system
What does the term ‘eczema’ mean?
Comes from the Greek word ‘to boil’, it is used to describe the itchy, red, dry skin which can sometimes become weeping, blistered, crusted, scaling and thickened
Recent studies have found that mutations in which gene may cause up to 50% of cases of atopic eczema?
Filaggrin gene
What is the filaggrin gene responsible for?
The conversion of keratinocytes to the protein/lipid squames that make up the outermost barrier layer of the skin (stratum corneum). A defect in this gene causes skin barrier dysfunction
How can a skin barrier dysfunction lead to eczema? (3)
- It leads to water loss from the skin, causing dryness and itching
- Makes the skin susceptible to allergens, leading to hyperactivity and induction of IgE autoantibodies
- Predisposes the skin to colonisation or infection by microbes such as staph aureus
What % of people with atopic eczema have a positive family history of atopic disease?
70%
What are the triggers that can cause an eczema flare up? (9)
- Irritant allergens - soaps, detergents
- Irritant clothing - synthetic fabrics, wool, silk, some cotton garments that are dyed
- Skin infections - staph. aureus, candida albicans
- Contact allergens - perfume-based products, metals and latex
- Inhalant allergens - pollen, pets
- Hormonal triggers - pre-menstrual flares, pregnancy
- Climate - extremes of temperatures
- Concurrent illness and disruption to family life - teething, emotional stress, ill health, lack of sleep
- Dietary factors - milk, egg, soy, peanuts - account for 75%
What are the complications caused by eczema?
- Infection - bacterial, HSV, fungal
2. Psychosocial - distress, depression, poor self-confidence, sleep disturbance
What does it mean that atopic eczema is typically an episodic disease?
It is a relapsing/remitting disease, with exacerbations that may occur as frequently as 2 or 3 times each month and remissions
How does atopic eczema typically present? (5)
- Very itchy skin
- Located on the flexor regions e.g. bends of the elbows and behind the knees
- Dry skin
- History of atopic triad - hay-fever/asthma
- In adults - eczema on hands may be primary manifestation
How can flare ups of eczema typically present?
Vary in appearance, from poorly demarcated redness to fluid in the skin (vesicles), scaling, or crusting of the skin
What are the differential diagnoses associated with atopic eczema?
- Psoriasis
- Allergic contact dermatitis
- Seborrhoeic dermatitis
- Fungal infection
- Scabies or other infestations
In terms of signs/symptoms, how is psoriasis different to eczema?
Psoriasis is less itchy, well-circumscribed, reddish, flat-topped plaques with silvery scales, typically symmetrical.
What are the categories that eczema can be placed in, depending on severity? (5)
- Clear - no active eczema
- Mild - areas of dry skin, infrequent itching
- Moderate - areas of dry skin, frequent itching and redness
- Severe - widespread areas of dry skin, incessant itching and redness (with or without excoriation, extensive skin thickening, bleeding, oozing, cracking)
- Infected - if eczema is weeping, crusted or there are pustules, with fever or malaise
In addition to categorising eczema based upon its appearance, what else needs to be assessed? (4)
The psychological impact of eczema;
- None
- Mild
- Moderate
- Severe
In someone with mild eczema, what is the recommended treatment plan? (4)
- Prescribe generous amounts of emollients
- Consider prescribing hydrocortisone 1% for areas of redness and treatment should be continued for up to 48 hours after the flare up has been controlled
- Advice and information on self-care and clothing, diet etc.
- Routine referral to dermatologist if eczema is not controlled
In a person with moderate eczema, what is the treatment plan? (6)
- Prescribe generous amounts of emollients
- If the skin is inflamed - prescribed betamethasone validate 0.025% or clobetasone butyrate 0.05%
- Occlusive dressings or dry bandages
- If severe itch - non-sedating antihistamine e.g. certirizine, loratadine, fexofenadine
- Consider prophylaxis treatment includes topical calcineurin inhibitors
What is the recommended treatment plan for someone with severe eczema? (7)
- Consider need for immediate admission if suspected eczema herpeticum
- Prescribe generous amounts of emollients
- Betamethasone valerate 0.1%
- Occlusive dressings or dry bandages
- If severe itch - non-sedating antihistamine e.g. certirizine, loratadine, fexofenadine
- Consider oral corticosteroid if severe extensive eczema with psychological distress - 30mg prednisolone each morning for 1 week
- Preventative treatment - topical corticosteroids or topical calcineurin inhibitors e.g. tacrolimus or pimecrolimus
What is the first line treatment for infected eczema?
Flucloxacillin (or erythromycin if the person has a penicillin allergy)
As stated in the special senses dermatology slides, what are the endogenous types of eczema? (5)
- Atopic
- Seborrhoeic
- Discoid
- Pompholyx
- Gravitational
