Dermatitis/Eczema Flashcards
What are the two phases of eczema?
Acute phase
Chronic phase
What occurs during the acute phase of eczema?
Papulovesicular erythematous lesions
Oedema
Ooze
Scaling and crusting
What occurs during the chronic phase of eczema?
Thickening (Lichenification)
Elevated plaques
Increased scaling
What is contact allergic dermatitis?
Dermatitis in response to chemicals, topical therapies, nickel, plants etc
What is the immunopathology of contact allergic dermatitis?
Langerhans cells in the epidermis processes antigen
Processed antigen is then presented to Th cells in the dermis
Sensitised Th cells migrate into lymphatics and then to regional nodes where antigen presentation is amplified
How can specific substances causes contact dermatitis be identified?
Patch testing
What does patch testing entail?
Batteries of allergens are places in small wells
Applied to the back of the skin
Left in place for 48 hours
Reactions are checked after 96 hours
What is irritant (contact) dermatitis?
Non-specific physical irritation rather than a specific allergic reaction
What % of school aged children have atopic eczema?
25%
What are the signs of atopic eczema?
Pruritis Ill-defined erythema and scaling Generalised dry skin Flexural distribution Association with other atopic diseases
What are the chronic changes seen in atopic eczema?
Lichenification
Excorition
Secondary infection
What is the criteria for diagnosing atopic eczema?
Itching + 3 or more:
- Visible flexural rash
- Hx of flexural rash
- Person history of atophy
- Generally dry skin
- Onset before age 2
What is the general treatment for eczema?
Plenty of emolliients Avoid irritants including shower gels and soaps Topical steroids Treat infection Phototherapy Systemic Immunosuppressants Biologic agents
What causes Eczema herpeticum?
Herpes simplex virus
What is the appearance of eczema herpeticum?
Monomorphic punched-out lesions
