Dermatitis Flashcards
What is parakeratosis?
Persistence of nuclei in the keratin layer
What is acanthosis?
Increased thickness of epidermis
What is spongiosis?
Oedema between keratinocytes
What does the acute phase of eczema present as?
Papulovesicular erythematous lesions, with oedema, scaling and crusting
What does the chronic phase of eczema present as?
Thickening elevated plaques with increased scaling
What is the key symptom of dermatitis and eczema?
Itch
What is the pathogenesis of contact allergic dermatitis?
Delayed type IV reaction
What is the immunopathology of contact allergic dermatitis?
The Langerhans cell in epidermis processes the antigen.
The antigen is then presented to T helper cells in the dermis..
The T helper cells then migrate into the lymphatics and then to regional nodes where antigen presentation is amplified.
How can specific substances be tested for in contact allergic dermatitis?
Patch testing
How long are the allergens left on the skin for in patch testing?
48 hours
When are reactions to the allergens checked?
96 hours (4 days)
What is contact irritant dermatitis?
Non-specific physical irritation commonly to soap/detergent/cleaning products
