Eczema Flashcards
What are the features of atopic dermatitis?
- Chronic, relapsing skin disorder (chronic disease with recurrent flares)
- Dry skin
- Red, inflamed scaly rash
- Intense pruritus (itch)
What is atopic dermatitis usually associated with?
Personal or family history of atopic disease e.g. asthma, allergic rhinitis, atopic dermatitis
What is the atopic march?
The progression of allergic conditions that occur incl. atopic dermatitis, food allergy, asthma and allergic rhinitis (atopic dermatitis is usually one of the first things to manifest in patients with atopy)
What are the diagnostic criteria for atopic eczema?
Must have an itchy skin condition in the last 12 months and 3 or more of:
1) Onset below age 2
2) History of flexural involvement
3) History of generally dry skin
4) Personal history of other atopic disease (or in first degree relative if < 4)
5) Visible flexural dermatitis
When does atopic dermatitis present?
- Mostly first year of life and between 1-5
- Rarely first time in adulthood
- 20% of children, 2-3% of adults (most people grow out of it)
What % of patients with atopic dermatitis eventually develop allergic rhinitis or asthma?
50%
What are environmental factors that cause atopic dermatitis?
1) Allergens
2) Irritants
3) Dietary factors
4) Infections
5) Pollutants
6) Stress
7) Weather change
What are the immunological causes of atopic dermatitis?
1) Abnormal Th2 immune response
2) IgE
What are genetic causes of atopic dermatitis?
1) Family history
2) Gene predisposition
3) Defective skin barrier
What does filaggrin do?
Filaggrin is a protein within skin that helps bind together the top layer of skin (keratinocytes), keeping moisture inside skin and preventing antigens getting inside the skin
Describe barrier dysfunction in eczema
- 40% of people who carry the filaggrin mutation develop eczema
- Filaggrin gene mutation causes barrier dysfunction which allows antigen to enter the skin, causing an inflammatory Th2 immune response
- These patients are also more likely to have other atopy
- More likely to have mutation if have significant increased hyperlinearity of palms
How does eczema present in infants?
Classically head and neck affected (and other areas esp. flexural areas)
What is eczema often confused with in infants and how is it different?
- Seborrheic dermatitis = overgrowth of malassezia yeasts on skin, which is also v common in babies
- Eczema is often a lot more itchy
How does eczema present in children?
- Flexural sites of skin - antecubital and popliteal fossae
- Around neck and skin creases
How does eczema present in adults?
- Hand dermatitis
- Antecubital and popliteal fossae
- Back of neck
How is the rash in eczema different from the one in psoriasis?
It is not as clearly demarcated
What are clinical features of eczema present in certain patients?
1) Lichenification
2) Periorbital eczema Dennie Morgan fold
3) Xerosis
4) Excoriations
5) Prurigo
Describe lichenification
- Increase skin marking (thickening)
- Brought about by chronic eczema (not acute)
- Develops over a period of time and is made worse by rubbing the skin persistently
Describe periorbital eczema
Eczema can occur around the eyes and can be made worse by allergic conjunctivitis
What are Dennie Morgan folds?
Pronounced infraorbital folds around the eye that are a classical feature of eczema
Describe xerosis
- Very dry skin all over without active eczema
- Need to moisturise skin to correct the epidermal dysfunction
What are excoriations?
- Marks from scratching due to itchy skin
- Many patients will scratch until they bleed - gives relief but not good
What is (nodular) prurigo?
- Marks from scratching skin
- Thickened areas on the skin with eroded tops
What happens with infections in eczema?
- May present with yellowy, honeycomb-like, serous dried crust over eczema
- Can be weepy and increasingly score
- Can be difficult to see if it is infected
Why are infections more common in eczema than psoriasis?
In part due to increase barrier dysfunction
What types of infections can happen in eczema?
- Skin infections
- Higher rate of colonisation with S.aureus
- HSV
What happens to eczema in adulthood?
- Most children outgrow the disease
- But as adults they may continue to have localised problems with dermatitis esp. hand dermatitis
What complications can HSV lead to in eczema?
- Eczema herpeticum (red dots on face)
- Patient has lots of small cuts on the skin which means that infections like HSV can easily get in
- Sometimes can also see vesicles on the skin
- Can be serious bc can cause corneal ulceration if the cornea is affected which needs to be treated quickly with IV aciclovir
Why and how is the amount of S.aureus tried to be reduced on the skin of eczema patients?
- Bc S.aureus on the skin can lead to repeated episodes of infection and worsening of their eczema
- Antimicrobial washes or bleach baths
What are co-morbidities that occur with eczema?
- Atopic co-morbidities
- Allergic contact dermatitis
- Infection
- Autoimmune disease
- Skin pain
- Sleep disturbance
- Neuropsychiatric problems
- Cardio-metabolic issues
What are key problems about living with eczema?
- Itch
- Sleep
- Social interactions
- Control
What topical treatments are used to treat eczema?
1) Moisturisers/emollients
2) Topical steroids - no rebound problem, but still want to be cautious so instruct patients how much and how to use
3) Calcineurin inhibitors - young children, face, around eyes, safe alternative or to wean steroids, can burn at first but wears off
4) Antiseptic washes
5) Wet dressings - wet wraps to alleviate symptoms
What medications are used to treat eczema?
1) Intermittent courses of oral steroids (v effective)
2) Phototherapy - some can be photo-aggravated so only use in patients whose eczema gets better in sun (difficult to tell bc often heat makes it worse so don’t know if it is sun or heat and sweat)
3) Methotrexate
4) Cyclosporin - brings immune system down to normal, not immune suppression
5) Dupilumab (v effective for some patients)
What type of biologic is used in eczema?
Dupilumab (IL-4 and IL-13 inhibitor)
What do IL-4 and IL-13 do?
1) IL-4 recruits Th2 cells in the skin
2) IL-13 recruits eosinophils and IgE within the skin
How is use of biologics different in eczema from psoriasis?
Can be used much more freely in eczema - only had to try one systemic therapy and no specifics about disease severity just severe
What score is used to measure severity of eczema?
EASI
What are potential side effects of dupilumab?
- Conjunctivitis
- Enthesitis
- Arthritis
