Eczema and Dermatitis Flashcards
What is the definition and aetiology of eczema
Dermatitis (interchangeable) which is inflammation of the skin.
Aetiology is a combination of genetic factors such as Filaggrin mutations (filaggrin is a protein which binds keratin fibres in epidermal cells), immune and reactivity to stimuli.
What are the subtypes of eczema?
Endogenous: Atopic, seborrhoeic, discoid, varicose, pompholyx.
Exogenous: Contact or photoreaction
Describe features of atopic eczema
Itchy inflammatory skin condition which is associated with asthma, allergic rhinitis, conjunctivitis and hay fever.
It has high levels of IgE with genetic and immune aetiology. Often affects infants but 75% will grow out of it by puberty. Can affect flexures
Skin is erythematous and oozing, may have vesicles.
What are the complications of atopic eczema
- Bacterial infections by staphylococcus aureus.
- Viral infections eg, molluscum, viral warts or eczema herpeticum (herpes)
- It can also cause tiredness, growth reduction and have a psychological impact.
What areas of the skin are affected in infant atopic eczema
Often facial component with perioral sparing. Many can develop secondary infections. It can be aggravated by food
What are the investigations for eczema?
Clinical diagnosis however may need to do some investigations eg, bloods before DMARD use, patch testing, swabs if concern about secondary infection
Describe features of contact dermatitis
It can be irritant/allergic which is precipitated by an exogenous agent. Irritants have a direct noxious effect on the skin barrier. Allergic is a type IV hypersensitivity reaction
What are some common allergens for contact dermatitis
Nickel: jewellery, zips, coins.
Chromate: Cement or tanned leather,
Cobalt: pigments/dyes,
Colophony: Glue, adhesive tapes, plasters,
Fragrance: cosmetics, creams or soaps
Describe features of venous dermatitis and the management
Occurs when underlying venous disease usually due to incompetence of deep perforating veins. Stagnation of fluid causes gentle stretch of skin causing dermatitis.
Management: emollients, mild-mod topical steroids. Compression bandages/stockings and consider venous surgical intervention.
Describe features of erythrodermic eczema
Characterised by widespread redness (>90%) and is a dermatological emergency
What does the following image show?
Pompholyx eczema. Intensly itchy vesicles which erupt inthe hands.
What does the following image show?
Eczema herpeticum. It is eeczema infected with HSV 1/2. Monomorphic, punched out lesions which are usually 1-3mm in diameter.
Children should be admitted for IV aciclovir as it is potentially life threatening
What is the management of eczema?
- Avoid tirggers, apply emollient generously.
- Topical steroids. Second line steroid sparing agent = topical calcineurin inhibitor
- Light therapy
- Systemic therapies
What are examples of systemic therapies for eczema?
- Oral steroids if severe eg, erythroderma.
- DMARDs - Methotrexate, ciclosporin, azathioprine
- Biologics (severe eczema which is not responding to traditional systemic therapy) eg, dupilumab.
Name an example of a mild, moderate, potent and very potent steroid and the areas not to use them on
Mild - 0.1/0.5% hydrocortisone
Moderate - Eumovate. DO not apply on eyelids.
Potent - Betnovate. Do not apply to face, groin, armpits or genitals or children
Very potent - Dermovate. Do not use on face, groin, armits, genitals, children or psoriasis
