CP10-2 Inflammatory Skin Tumours Flashcards
What cells give us skin pigment and protect us from UV damage?
Melanocytes
What are the 5 main layers if the epidermis from top to bottom?
Keratanised squamous
Granule cell layer
Prickle cell layer
Basal cell layer
Basal lamina
What are examples of non infectious inflammatory skin diseases?
Dermatitis/psoriasis
Blistering
Connective tissue diseases e.g. lupus
Skin lesions as signs of systemic disease
Skin lesions caused by metabolic disorders
What are s9me major tissue reaction patterns?
Lichenoid
Psoriasiform
Spongiotic
Vesiculobullous
What are examples of inflammatory skin diseases with lichenoid reaction patterns?
Lichen planus
Lupus erythematous
Dermatomyositis
What is an example of inflammatory skin diseases with a psoriasiform reaction pattern?
Psoriasis
What is an example of an inflammatory skin diseases with a spongiotic reaction pattern?
Eczema
What are some examples of inflammatory skin diseases with vesiculobullous reaction patterns?
Pemphigoid
Pemphigus
Dermatitis herpetiformis
What is the epidemiology of eczema/dermatitis?
5% if children in UK
What are the three stages of dermatitis/eczema?
1 - Acute dermatitis - skin is red and weeping serous exudate +/- small vesicles
2 - subacute dermatitis - skin is red, producing less exudate with pruritus and crusting
3 - chronic dermatitis - skin becomes thick and leathery secondary to scratching
What microscopy findings are found in eczema/dermatitis?
Spongiosis (intracellular oedema with epidermis)
Chronic inflammation - predominantly on superficial dermis
Epidermal hyperplasia and hyperkeraosis - becomes more marketed as dermatitis changes from acute to chronic
What is atopic eczema?
A type 1 hypersensitivity reaction to allergens, often associated with asthma and hay fever. Usually starts in childhood but occasionally can present in adulthood. Associated with family history.
What is contact irritant dermatitis?
When direct injury to skin by an irritant causes dermatitis e.g. acid, strong detergent etc…
What is contact allergic dermatitis?
A delayed type 4 hypersensitivity reaction where an irritant e.g. nickel, dyes, rubber, combine with epidermal proteins to become immunogenic.
What types of dermatitis have an unknown aetiology?
Seborrhoeic dermatitis
Nummular dermatitis
What is seborrhoeic dermatitis?
Dermatitis in areas rich in sebaceous glands e.g. scalp, forehead and upper chest
What is nummular dermatitis?
Dermatitis characterised by coin shaped lesions
What is the epidemiology of psoriasis?
1- 2% of population
What are symptoms and signs of psoriasis?
Well defined, red oval plaques on extensor surfaces (knees, elbows, sacrum)
Fine silvery scale
Auspitz sign - removal of scale causes small bleeding point
+/- pitting nails
+/- sero-negative arthritis
Potentially oral manifestations.
How does psoriasis appear under the microscope?
With psoriasiform hyperplasia which is characterised by:
- regular elongated club shaped rate ridges
- thinking of epidermisover dermal papillae
-parakeratotic scale (contain nuclei)
- munro microabcesses (collections of neutrophils in the scale)
What is the pathogenesis of psoriasis?
Clinical and microscopic features reflecting massive cell turnover which is idiopathic but possibly autoimmune where a trigger factor leads to a dysfunctional immune reaction.
What increases your risk of psoriasis?
Genetics - PSORS genes
Environmental triggers e.g. infection, stress, trauma, drugs
What comorbidities are associated with psoriasis?
Arthyropathy
Psychological affects
CVD
Increases risk of non-melanoma skin cancer, e.g. BCC, and lymphoma
Where are lichen planus rashes found?
On flexor surfaces
Mucous membranes e.g. oral cavity
Genitals
What is lichen planus?
An idiopathic inflammatory skin condition potentially caused by a type 4 hypersensitivity reaction which affects adults and is often self limiting. It usually lasts around 1-2 years.
What is lupus erythematous?
An autoimmune disorder which primarily affects connective tissues of the body as autoantibodies are directed at various tissues.
What is lupus which only affects the skin known as?
Discoid lupus erythematous (DLE)
What skin symptoms do patients with lupus erythematous present with?
Red scaly patches on sun exposed skin +/- scarring
Scalp involvement causing alopecia
What skin symptom is characteristic of SLE?
Butterfly rash on nose and cheeks