Inflammatory skin, skin tumours and disease of the eye Flashcards
What are the common infections of the cornea and conjunctiva of the eye?
VZV - trigeminal nerve can cause scarring to the eye
Chlamydia - 2 types:
-trachoma - can cause blindness
- Types D-K - mild disease during birth (infection in genital tract: conjunctivitis)
What conditions are associated with development of cataracts in the lens of eye?
Lens becoming opaque Senile degeneration Rubella Downs syndrome Diabetes mellitus
What conditions are associated with retinal infections? What do they cause in adults/children
Toxoplasmosis - cat poo - congenital infection causes severe bilateral impairment, adults - focal inflammatory disease
Taxocara canis - infected dog faeces - can cause localised infection
What are the main retinal vascular disease causes?
Diabetic retinopathy
Hypertensive retinopathy
Ischaemic retinopathy
What are the two types of macular degeneration? What are they due to?
Dry macular degeneration - age, progressive visual impairment
Wet - new vessel growth beneath retina
What are the two tumours that arise from the eye?
Retinoblastoma - loss of RB gene
Melanoma - arise from melanocytes in the eye - treat with surgery (remove eye)
What is dermatitis commonly referred to as?
Eczema
What are the 3 stages of dermatitis/eczema?
Acute - weeping serous exudate, red skin, small vesicles
Subacute - less exudate, red skin, ITCHY, crusting
Chronic - leathery skin secondary to scratching
What is the main microscopic features of dermatitis?
- SPONGIOSIS - oedema in the epidermis
- Hyperkeratosis and hyperplasia of epidermis
What are the different types of eczema?
Atopic eczema - childhood - type I hypersensitivity reaction
Contact irritant dermatitis - direct injury to skin by irritant e.g. acid
Contact allergic dermatitis - ( e.g. metals) allergens combine with epidermal proteins and become immunogenic
Unknown aetiology
What are the clinical characteristics of psoriasis? What is the Auspitz sign?
Red oval plaques occurring in extensor surfaces (knees, elbows, sacrum)
- silvery sales
- Auspitz sign - removing scales will cause small bleeding points
What is the distinct microscopic appearance of psoriasis?
Psiariasform hyperplasia
- regular elongated clubbed shaped rete ridges
- thinning epidermis
- Parakeratotic scales
What is the pathogenesis of psoriasis?
Massive cell turnover
What genetic/environmental factors are associated with psoriasis?
PSORS (genetic)
Stress, trauma, infection, drugs
What are the characteristic features of Lupus?
Red scaly skin (sun exposed)
Butterfly rash
Autoimmune disease - effects connective tissues of body (particularly kidneys)
What is the presenting feature of dermatomyositis? What systemic disease is it associated with?
Heliotrophic rash - peri-occular oedema and erythema
Visceral cancer
How do dermatitis herpetiforms present? What condition are they associated with?
- Small itchy blister
- Associated with coeliacs disease
What is acanthosis nigricans? What disease is it associated with?
Dark warty lesions under armpits
Visceral malignancy
What is necrobiosis lipoidica? What disease is it associated with?
Red and yellow plaques in legs
Diabetes
What are the clinical features of basal cell carcinoma?
- Most common skin tumour
- due to sun exposure (mainly)
- Rarely metastasise
- Nodule -> ulcer (rodent ulcer) (look like basement cells!!)
What are the clinical features of squamous cell carcinoma?
- UV radiation/actinic - mostly occurs of face and hands
- Microscopic apprende = look like squamous cells!
- Nodules -> ulcerate
- Rarely metastasise
What usually precede SSC?
acinitic keratosis
What is the function of melanin>
Protect epidermal cell nuclei from UV radiation
What are naevi?
moles - benign melanocytes
What are the distinguishing features of melanomas vs naevi?
Asymmetrical
Borders uneven
Colour variation
Diameter >6mm
What are the risk factors for melanoma?
- Sun exposure - short, intermittent
- Race - celtic red hair, blue eyed, don’t tan
- Family history
- Giant congenital naevi
What are the prognostic factors for melanoma?
Breslow thickness (thicker the tumour, worse the prognosis)
Site - BANS - back, arms, neck, scalp - poorer prognosis
What is the treatment for melanomas?
Excision of tumour and lymph if invaded
