Flashcards in Diseases of the Skin and Eye Deck (69):
Virus that can cause scarring of the cornea and conjunctiva
2 forms of chlamydia that damage the cornea and conjunctiva
Trachoma: tropical disease. Common cause of blindness.
Chlamydia types d-k- mild disease: acquired during birth from infection in genital tract.
6 causes of cateracts
Uveitis-inflammation of uvea (middle eye)
2 retinal infections
Toxoplasma: cat is host. Congenital infection causes severe bilateral disease. Aquired causes focal inflmmatory disease.
Toxocara Canis: from infected dog faeces, larva may migrate to retina and die causing localised inflammation.
3 types of retinal vascular disease
Hypertensive retinopathy- flame shaped haemorrhages and exudates
Diabetic Retinopathy-dot and blot haemorrhages and exudates
2 types of macular degeneration
Dry macular degeneration (90%) Age related, common >60yrs. Progressive visual impairment, no treatment.
Wet macular degeneration (10%) New vessel growth beneath retina. Treat with drugs and lazers. Drugs inhibit vessel growth, injected directly into the eye.
2 types of tumours of the eye
Rare, 10% familial. Loss of Rb gene. Tumour in the retinal, treat with enucleation.
Arise in the melanocytes of the uveal tract (iris, ciliary body or choroid)
Type 1: good prognosis
Type 2: poor. Treat with radiotherapy and surgery.
Another word for genital warts
Superficial bacterial infection
Deep bacterial infection
Fish tank granuloma
Caused by mycobacteium marium.
Mycobacterium leprae. Chronic granulomatous infection. can involve nerves.
3 stages of eczma
Red skin, weeping, serous exudate with or without vesicles.
Red skin, less exudate, really itchy and crusty
Skin thick and leathery, secondary to scratching
Intercellular oedema within epidermis that you find in eczma
Clinical characterisitics of dermatitis
Chronic inflammation-predominantly superficial dermis. Epidermal hyperplasia and hypekeratosis.
5 types of dermatitis
Contact irritant dermatitis
contact allergic dermatitis
Coin shaped lesions, a type of dermatitis
Removal of psoriasis scab causes small bleeding points
Microscopic appearace of psoriasis
-regular elongated club shaped rete ridges
-thinning of epidermis over dermal papilla
-parakeratoti (contain nuclei) scale
-collections of nuclei (munro microabscesses)
Pathogenesis of psoriasis
Massive cell turnover and inflammation
Causes of psoriasis
Genetic. Associated with MS/IBD
Environmental triggers-infection, stress, trauma, drugs, smoking.
Assocations of psoriasis
Cancer (Basal cell carcinoma)
Lupus that only affects the skin
Microscopic appearance of lupus
Thin, atrophic epidermis. Infalmmation and destruction of adnexal structures.
Immunofluorescence shows LE band due to IgG deposited in basement membrane. i.e. antigens are sandwiched between keratinocytes and basement membrane.
Perocular oedema (puffy eyes)
Photo sensitive distribution-heliotropic rash.
Myositis-prox muscle weakness. Can check for creatinine kinase.
Assocations of dermatomyositis
Microscopy of dermatomyositis
Fluid filled blisters
Superifical blisters. Immunofluorescence- intercellular
Deeper blisters- subepidermal. Immunofluorescence-basement membrane
Pathogenesis of pemphigus
Loss of cohesion between keratinocytes resulting in an intracepidermal blister. Affects mucous membranes-mouth, anus etc.
Pathogenesis of pemphigoid
Elderly-large tense bullae, do not rupture easily, Can be localised or extensive.
Young patients. Small, intensly itchy blisters. IgA deposition in dermal papillae in IMF. Neutrophil microabscesses in dermal papillae.
Dar warty lesions in armpits, associated with internal malignancy.
Red and yellow plaques on legs. Associated with DM
Red nodules on shins. Associated with infections elsewhere e.g. lung.
Connective tissue tumours in the skin
Porphyria Cutanea Tarda (PCT)
20% inhertied, 80% acquired (hep C or alcohol)
Enzyme deficiency- uroporphyrinogen decarboxylase. Results in a build up of porphyrin in the skin-tissue damage when exposed to sunlight. Blisters and scarring. Porphyrins in urine-go dark on light exposure
Most common malignant tumour
Basal cell carcinoma
Are metastases common in BCC?
Causes of BCC
Sun exposure-pale skin more susceptivle
Early clinical manifestation of BCC
Late clinical manifestation of BCC
Roden tulcer with rolled edge. Ill defined and infiltrative. Tumour composed of islands of basaloid cells with peripheral palor. Can be pigmented.
Squamous cell carcinoma risk factors
UV radiation- tropical counties.
Hydrocarbon exposure-tars, mineral iols, soot
Chronic scars/ulcers e.g. Marjolin's ulcer
Drugs e.g. for melanoma
Appearance of SCC
Nodule with ulcerated, crusted surface and trabeculae of squamous cells showing cytological atypia.
5% metastasise- typically in lip, ear and perineum
High risk if bigger than 2cm or thicker than 4mm
Pre malignant disease that predisposes you to SCC
(grandpa) Scaly lesion with erythematous base. Only rarely progresses to invasive disease
May spontaneously resolve
Benign melanocytic cancer
Malignant melanocytic cancer
2 types of naevi
Superficial-congenital or aquired
Deep-blue naevi (mongolion spot)
Families with increased incidence of melanoma. Multiple clinically atypical moles
Dysplastic naevus syndrome
Much rare than BCC and SCC. Incidence is increasing. Very dangerous and can metastasize widely.
Diagnosis of melanoma
Causes of melanoma
Sun exposure-short intermittent sever exposure
Race-rarer in people with darker skin
Family history-dysplastic naevus syndrome
Giant congential naevi-10% turn malignant
Slow growing, flat, pigmented patches that grow on the faces of elderly people. Chronic skin damage. May eventually invade dermis to become lentigo maligna melanoma, which have the potential to metastasis
Acral lentigenous melanoma
Palms and soles. Commonest form in afro caribbeans- no marked skin damage as opposed to lentigo maligna
Commonest type of melanoma in britain
Superficial spreading malignant melanoma
Clinical appearace of superficial spreading malignant melanoma
Late- blue/black nodule
Genetic predisposition in superficial spreading malignant melanoma
BRAF mution-possible targe for anticancer agents
Starts as a pigmented nodule, sometimes with ulceration. Poor prognosis.
Prognostic factors for melanoma
Breslow thickness- measure the thickness from granular layer of epidermis to base of tumour. 5yr survival rates. If 4mm 45-60% 5yr survival
Site of melanoma that give rise to a poorer prognosis
BANS- back, arms, neck scalp