Flashcards in CP 63 - inflammatory skin diseases Deck (71):
what the 2 types of chlamydia
a] Trachoma is a tropical disease which infects the corneum and conjuctiva. Common cause of blindness.
b] Mild disease due to Chlamidia types d-k, aquired during birth from infection in genital tract
what can cause retina infections
toxoplasma - cat poo
toxocara canis - dog poo
what is macular degeneration
Damage to macule, the central part of vision.
-dry - age related
-wet - new vessel growth beneath retina
what can cause cataracts
what conditions can happen in the retina?
what tumours can arise from the retina?
retinoblastoma - genetic, occurs in retina,
Melanoma - arise from melanocytes of Uveal tract (Iris, ciliary body or choroid)
what is leprosy?
chronic granulomatous infection which can involves nerves, loss of sensation
what causes leprosy?
what are some of the common fungal infections
ringworm - tinia pedis (athelete's foot), tinea cruris (groins) - infectiob by trichophuton species
trush - candida infection
what is another name for eczema?
what are the 3 clinical stages of dermatitis
1 - acute dermatitis (skin red, weeping serous exudate +/- small vesicles.)
2- subacute dermatitis (skin is red, less exudate, itching ++, crusting.)
3 - chronic dermatitis (skin thick and leathery secondary to scratching)
what are the microscopy of the different stages of dermatitis
1 - spongiosis (intercellular oedema within epidermis)
2 - Chronic inflammation - predominantly superficial dermis.
3 - Epidermal hyperplasia and hyperkeratosis - mild in acute dermatitis, marked in chronic dermatitis
what can atopic eczema be associate with?
asthma and hay fever
what kind of reaction id eczema?
type 1 hypersensitivity to allegen
what is contact irritant dermatitis
direct injury to skin by irritant, eg acid, alkali, strong detergent, etc
what is contact allergic dermatitis
- nickel, dyes, rubber. Act as haptens which combine with epidermal protein to become immunogenic.
what is seborrhoeic dermatitis ?
affect areas rich in sebaceous glands: scalp, forehead, upper chest
what is nummular dermatitis
coin shaped lesions
what is psoriasis?
well defined, red oval plaques on extensor surfaces - knee elbows, sacrum
fine silvery scale, Auspitz sign
what is the distinct psoriasiform hyperplasia
regular elongated club shaped rete ridges
thinning of epidermis over dermal papillae
collections of neutrophils in scale
what is the pathogenesis of psoriasis
massive cell turnover
what is the aetiology of psoriasis
problems in the MHC on chromosome 6p2 (same area involved in other autoimmune disorder)
required environmental trigger factors
what does patients with psoriasis have increased risk of?
non-melanoma skin cancer
what types of different lupus erythmatosus are there?
discoid - skin only
systemic - visceral disease +/- skins
how is lupus erythematosus present clinically?
Red scaly patches on sun-exposed skin +/- scarring, scalp involvement causes alopecia
what would butterfly rash on cheek and nose indicate?
what sort of condition is lupus erythematosus
Auto-immune disorder primarily affecting connective tissues of the body
what are the microscopical feature of lupus erythematosus
thin atrophic epidermis, . Inflammation and destruction of adnexal structures.
LE band - IgG deposit in basement membrane
what are presentation of dermatomyositis
peri-ocular odema and erythema (heliotropic rash)
what does dermatomyositis indicate in some population?
In adults 25% associated with underlying visceral cancer
what does the bullous disease
Formation of fluid filled blisters
what does intra-epidermal bulla represent?
what does sub-epidermal bulla represent?
what is pemphigus
Group of disorders characterised by loss of cohesion between keratinocytes resulting in an intraepidermal blister.
how does pemphigus manifest?
Autoantibodies, directed against intercellular material
how does bullous pemphigoid manifest?
Autoantibodies to glycoprotein in basement membrane.
what is deematitis herpetiformis
Small intensely itchy blisters. Extensor surfaces
what can dermatitis herpetiformis indicate?
what is acanthosis nigricans
darty warty lesions in armpits
what can acanthosis nigricans indicate
what can xanthoma indicate
what can porphyria indicate
problem with production of haem
what can porphyria be presented?
acute abdo pain, psycho problem, peripheral neuropathy, urine goes dark on light exposure
what is the most common form of porphyria?
porphyria cutanea tarda
what can cause porphyria cutanea tarda
20% FH, 80% acquired through Hep C
what is the most common malignant skin tumour?
basel cell carcinoma
aetiology for BCC?
sun exposed site (face), occasionally radiotherapy
what are some of the clinical presentation for BCC?
early - nodule, late - ulcer
microscopically - tumour composed of islands of basaloid cells with peripheral palisade
what can cause squamous cell carcinoma?
UV irradiation (sun exposed)
radiotherapy - treatment of melonoma
chemical exposure - tars, mineral oils
immunosuppression - renal transplant patients at increased risk
drugs (new drugs for melanoma)
what are some of the clinical presentation of SCC?
Nodule with ulcerated, crusted surface
is SCC particularly invasive
no really (still more invasive for BCC) -
what is actinic keratosis
dry scaly patches of skin caused by damage from years of sun exposure - patches can be pink brown in colour
pre-malignant disease of SCC
what is the cause of actinic keratosis
dysplasia to squamous epithelium
what is the function of melanocytes
to form melanin which is transferred to epidermal cells to protect the nucleus from UV radiation
what are the benign tumour arise from melanocytes?
what are the malignant tumour arise from melanocytes?
what is naevi?
local benign collections of melanocytes
what is naevus syndrome
families with increased incidence of melanoma, multiple clinically atypical moles, increased risk of developing melanoma
what is the acronym for identifying naevus and melanoma
what is the causes of melanoma
sun exposure (especially short intermittent severe exposure)
race - celtic with red hair
FH - dysplastic naevus syndrome
what is lentigo maligna
elderly ppl have face patches which is slow growing, flat, pigmented patches
what is the microscopic feature of lentigo maligna
Proliferation of atypical melanocytes along basal layer of epidermis. Skin also shows signs of chronic sun damage.
will lentigo maligna become invasive?
might do later on in the disease, melanocytes may invade dermis with potential to metastasis
where does acral lentigenous melanoma affect the most?
palms and soles, occasionally subungula
which race is acral lentigenous melanoma affect the greatest?
what is the superficial spreading melanoma
commonest type in Britain
where does superficial spreading melanoma
Early: flat macule. Late: blue/black nodule
what is nodular melanoma
Starts as pigmented nodule. +/- ulceration. Poor prognosis.
what is the microscopic features of nodular melanoms
invasive atypical melanocytes invade dermis to produce nodules of tumour cells
what is breslow thickness
measure on microscope from granular layer of epidermis to base of tumour