Atopic Dermatitis Flashcards
What is the difference between atopic dermatitis and eczema?
Nothing, they are the same thing!
What does atopic mean?
Allergic
Atopic dermatitis is not always atopic. True or false?
True!
It is a silly name, because you can get non-atopic atopic dermatitis
Who gets atopic dermatitis?
Children
40% of children with atopic dermatitis will continue to have it into adulthood
Risk factors for atopic dermatitis?
Atopy Family history Not breast feeding Colder climates Being in a higher social class Living in urban areas, pollution
Why does being of a higher social class increase the risk of getting atopic dermatitis?
The hygiene hypothesis may be to blame
Living in a very clean sterile environment can cause over-expression of pro-inflammatory T cells, increasing the chance of the person becoming atopic
Describe the distribution and features of eczema rashes depending on age?
Infants:
- generalised
- cheeks, forehead, outer limbs
Childhood:
- becomes more localised to skin flexures
- lichenification
- hyperpigmentation
Adults:
- more dry
- more lichenification
- recurrent S. aureus infections
Clinical features of atopic dermatitis?
Itchy, erythematous, scaly rash
Lichenification: skin becomes hard and leathery
What is lichenification?
When the skin becomes leathery and hardened after long term scratching of the skin
What are the complications of atopic dermatitis?
Lichenification: skin becomes hard and leathery
Infection with S. aureus
Infection with herpes virus: eczema herpeticum
Cataracts
What is erythrodermic eczema?
When the eczema covers over 90% of the body
Clinical features of eczema herpeticum?
Vesicular lesions around the site of the eczema
Systemic features: pyrexia, lymphadenopathy, malaise
Describe the pathogenesis of atopic dermatitis?
An abnormal epithelial barrier means that antigens and irritants can penetrate and come into contact with immune cells
Immune response occurs which creates the erythema, itching and damage. Scratching causes further damage to barrier
An immunological response occurs in the immune cells, Ig is created against the allergen/irritant meaning the person is now sensitive to it.
List some triggers that may cause eczema?
House dust mite: have proteases which damage the epithelial barrier, and can also become allergens
Food
Animals
Detergents
Drooling / lip licking
Diagnosis of atopic dermatitis?
Clinical diagnosis by looking at the rash, taking a history, establishing if there are any triggers
