Flashcards in Photocarcinogenesis Deck (52)
(blistering at site of infection)
Caused by staphylococcus toxin A
Staphylococcal scalded skin syndrome
Caused by staphylococcus toxin B
Most common in children
Low mortality rates
Organism usually causing cellulitis
Beta haemolytic strep
Another name for basal cell papilloma
Appear as firm, elevated pigmented nodules which may feel like a button in the skin
They are often found on the legs and commoner in females
There may be a history of trauma or insect bite
Rapidly growing epidermal tumours which develop central necrosis and ulceration
They occur on sun exposed sites and can grow to 2-3cm across
Whilst they may resolve spontaneously, best to surgicaly remove as they can mimic squamous cell carcinoma
Where does Bowen's disease most commonly develop?
Lower womens legs
Where would you usually develop a pilar cyst?
Key characteristics or "hallmarks" of cancer
1. Insensitivity to growth signals
2. Insensitivity to anti-growth signals
3. Evade death (apoptosis)
4. Limitless potential to divide
6. Invasion and metastasis
Basal cell carcinoma and exposure
Squamous cell carcinoma and exposure
Melanoma and exposure
Lattitude and skin cancer
Incidence increases closer to equator
Skin colour and eye colour and cancer
Red/fair haired individuals with blue eyes and freckling
Where would patients with Xeroderma pigmentosum (XP) develop skin cancer?
Skin exposed areas
Visible light spectrum
UV signature mutation
Cytosine to thymine (at dipyrimidine sites)
Nucleotide excision repair
Base excision repair
Double strand break repair
Which UV is mainly responsible for initiating mutations?
Which UVs are responsible for promoting mutations etc
Estiamted action spectrum for cancer in humans?
Age onset of MM?
Merkel cell skin cancer exposure
HPV associated with which types of skin cancer?
BCC and SCC
Metastases common in which type of cancers?
MM and MCC
(malignant melanoma and merkel cell carcinoma)
Most common site for BCC?
Face and 1/3 sun protected sites
Main site for SCC?
Sun exposed sited
Main sites for malignant melanom?
Face, legs, back
Main site for MCC?
Head/neck, sun exposed sited
BCC formed from which type of cell?
Major risk factor for BCC?
This is even BIGGER risk factor in SCC (65-250x)
Eating this poison can increase risk of BCC?
-same for SCC
Syndromes predisposing to BCC?
Basal cell nevus syndrome (Gorlin syndrome)
BCC risk factors
Intermittent sun exposure/sunburn Immunosuppression (10x)
?photosensitising drugs Family/personal history of BCC/SCC
SCC precursor lesions
Risk factors for SCC?
Chronic/cumulative sun exposure. Sunbeds.
Arsenic /petroleum products/organophosphates/smoking/scars/HPV ?photosensitising drugs
Family/personal history of BCC/SCC
SCC predisposing syndromes
Rothmund Thomson syndrome
Dystrophic epidermolysis bullosa
Precursor lesions for melanoma
Where are melanomas usually found?
Palms and soles
Growing under the nails
Risk factors for melanoma
Intermittent sun exposure/sunburn. Sunbeds
?photosensitising drugs/?heavy metals/?other occupational exposure Family/personal history of CM/BCC/SCC
Melanoma predisposing syndromes
Atypical mole syndrome
Drugs associated with photocarcinogenesis
UV and langerhans cells
UV reduced number of langerhans cells
UV and oxidative stress
Increases oxidative stress
UV and exogenous compounds
UV interacts with exogenous compounds