Pathology of Inflammatory Skin Disease Flashcards
What are different epidermal reaction patterns?
Spongiotic Psoriasiform Bullous and pustular Interface reactions - Lichenoid - Vacuolar
What are different dermal reaction patterns?
Oedematous Vasculopathic Inflammatory, including granulomatous Fibrosing Infiltrative
What does curettage yield?
Fragmented tissue
- Keratotic material/crust
- Epidermis
- Minimal dermis
For what may curettage be suitable?
Seborrhoeic keratoses
Superficial basal cell carcinomas
What does a shave biopsy yield?
Single piece of unfragmented epidermis +/- superficial dermis
For what may a shave biopsy be suitable?
Some keratoses
What is obtained from a punch biopsy?
Epidermis
Dermis
Sometimes subcutaneous fat
For what may a punch biopsy be suitable?
Inflammatory dermatoses Confirmation of suspected tumour, usually - Basal cell carcinoma - Squamous cell carcinoma Discrete small lesions
What is obtained from an incisional biopsy?
Epidermis
Dermis
+/- subcutaneous fat
May include fascia
For what may an incisional biopsy be suitable?
Blistering lesions, especially if roof delicate
Ulcerated lesions - some normal skin assists assessment
Inflammatory process extending into fat
What does an excisional biopsy allow?
Histological examination of entire lesion
Accurate assessment of depth and margins
For what may an excisional biopsy be suitable?
Intent to cure
Non-uniform lesions, especially pigmented
Suspected melanoma
When is a wide local excision done?
Usually after biopsy diagnosis of melanoma/other locally aggressive malignancy
What does a wide local excision remove?
Any residual lesion to level of subcutaneous fat
- May include fascia
What are the differential diagnoses of spongiotic reactions?
Eczema
Seborrhoeic dermatitis
Fungal infection
Early immuno-bullous disorder
What are the differential diagnoses of psoriasiform reactions?
Psoriasis Chronic spongiotic reactions Lichen simplex chronicus Psoriasiform keratosis AIDS associated dermatitis Reiter's syndrome
What are the differential diagnoses of blistering reactions?
Depends on
- Location of blister
- Process causing blister
- Contents of blister
- Presence and type of inflammatory reaction
- Presence of autoAbs
What are some important blistering reactions?
Genetic - Darier - Hailey-Hailey Impetigo Viral infections Immuno-bullous disorders - Pemphigus - Pemphigoid - Dermatitis herpetiformis Burns Erythema multiforme Drug reactions Arthropod bite reactions
What are the differential diagnoses of interface/lichenoid reactions?
Lichen planus Lichenoid drug eruption Fixed drug eruption Erythema multiforme Cutaneous lupus Dermatomyositis Graft vs host disease
What are the differential diagnoses of cutaneous small vessel vasculitis?
Infective
Immunological
- Immune complex
- Direct Ab associated
Define acantholysis
Loss of cohesion between keratinocytes
Define acanthosis
Epidermal hyperplasia
Define dyskeratosis
Permature keratinisation below granular layer
Define erosion
Incomplete loss of epidermis
