Dermatology Flashcards
(42 cards)
What are the different types of eczema?
Atopic Seborrheoic Discoid Pomphylx Varicose Contact allergic dermatitis Contact irritant dermatitis Photoaggravated
What is the commonest type of eczema?
Atopic
What is atopy?
Overactive immune response to environmental stimuli
What is atopic march?
Tendency to 3 commonly linked conditions - eczema, asthma and hayfever
What do filaggrin proteins do?
Bind the keratin filaments together and produce a natural moisturising factor
What can childhood eczema flares be associated with?
Infections/viral illness Environment: central heating, cold air Pets: if sensitised/allergic Teething Stress Sometimes no cause
Where does seborrheoic dermatitis commonly affect?
Mainly scalp and face
How does discoid eczema present?
Scattered annular/circular patches, itchy eczema
How does pomphylx eczema present?
Intensely itchy vesicles on the hands and feet
How is atopic eczema distributed in infancy?
Typically starts on the face/neck (cheeks common) but can spread more generally
How is atopic eczema distributed in older children?
Flexural pattern predominates (antecubital fossae, popliteal fossae, wrists, hands, ankles)
How does filaggrin expression play a role in atopic eczema?
Many have an abnormality in filaggrin and are deficient in it
What are the consequences of a loss of skin barrier function as is seen in filaggrin deficiency?
Loss of water
Irritants may penetrate (soap, solvents, detergent, dirt)
Allergens may penetrate (pollens, dust mite antigens, microbes)
Seborrheoic dermatitis is associated with the proliferation of various species of which skin commensal?
Malassezia in its yeast form
What is exogenous eczema?
Allergic eczema
Sensitised to allergen
Type IV hypersensitivity
What is the difference between eczema and dermatitis?
No difference, they are interchangeable
What are the two types of food allergy reactions?
Immediate (type I)
Late (type IV)
What are the symptoms of a type I reaction?
Lip swelling
Facial redness/itching
Anaphylactoid symptoms
What are the symptoms of a type IV hypersensitivity food allergy eczema reaction?
Worsening of eczema 24-48 hours after ingestion
GI problems
Failure to thrive
Severe eczema unresponsive to treatment
Severe generalised itching, even when the skin appears clear
How do you test for a food allergy that has an immediate reaction?
Blood test for specific IgE antibodies (RAST)
Skin prick testing
Beware of false positive tests and limitations of allergy testing
How do you test for a food allergy that has a late reaction?
There is no test
Dietary restrictions/eliminations for 6-8 weeks
Eliminate one food at a time
How is eczema treated?
Emollients Topical steroids Calcineurin inhibitors UVB light therapy Immunosuppressive medication
What are the different potencies of the available topical steroids?
Mild - hydrocortisone
Moderate - Eumovate (25x)
Potent - Betnovate (100x)
Very potent - Dermovate (600x)
How should steroid creams be used?
Once daily for 1-2 weeks
If improvement then use alternate days for a few more days
Then if stubborn/persistent areas can use twice weekly in these areas
If at any point the eczema starts flaring, go back to daily applications
