Photocarcinogenesis Flashcards Preview

Dermatology > Photocarcinogenesis > Flashcards

Flashcards in Photocarcinogenesis Deck (52):
1

Bullous impetigo
(blistering at site of infection)

Caused by staphylococcus toxin A

2

Staphylococcal scalded skin syndrome

Caused by staphylococcus toxin B
Most common in children
Low mortality rates

3

Organism usually causing cellulitis

Beta haemolytic strep

4

Another name for basal cell papilloma

Seborrhoeic wart

5

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

Dermatofibroma

6

Keratoacanthoma

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

7

Where does Bowen's disease most commonly develop?

Lower womens legs

8

Where would you usually develop a pilar cyst?

The scalp

9

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
5. Angiogenesis
6. Invasion and metastasis

10

Basal cell carcinoma and exposure

Intermittent exposure

11

Squamous cell carcinoma and exposure

Chronic exposure

12

Melanoma and exposure

Intermittent exposure

13

Lattitude and skin cancer

Incidence increases closer to equator

14

Skin colour and eye colour and cancer

Red/fair haired individuals with blue eyes and freckling

15

Where would patients with Xeroderma pigmentosum (XP) develop skin cancer?

Skin exposed areas

16

UVC wavelength

200-280 nm

17

UVB wavelength

280-315 nm

18

UVA wavelength

315-400 nm

19

Visible light spectrum

400-700 nm

20

UV signature mutation

Cytosine to thymine (at dipyrimidine sites)

21

NER

Nucleotide excision repair

22

BER

Base excision repair

23

DSB

Double strand break repair

24

MMR

Mismatch repair

25

Which UV is mainly responsible for initiating mutations?

UVB

26

Which UVs are responsible for promoting mutations etc

UVB/UVA

27

Estiamted action spectrum for cancer in humans?

298nm

28

Age onset of MM?

<20 years

29

Merkel cell skin cancer exposure

?cumulative

30

HPV associated with which types of skin cancer?

BCC and SCC

31

Metastases common in which type of cancers?

MM and MCC
(malignant melanoma and merkel cell carcinoma)

32

Most common site for BCC?

Face and 1/3 sun protected sites

33

Main site for SCC?

Sun exposed sited

34

Main sites for malignant melanom?

Face, legs, back

35

Main site for MCC?

Head/neck, sun exposed sited

36

BCC formed from which type of cell?

Keratinocytes

37

Major risk factor for BCC?

Immunosuppression (x10)
This is even BIGGER risk factor in SCC (65-250x)

38

Eating this poison can increase risk of BCC?

Aresenic
-same for SCC

39

Syndromes predisposing to BCC?

XP
Basal cell nevus syndrome (Gorlin syndrome)

40

BCC risk factors

Intermittent sun exposure/sunburn Immunosuppression (10x)
Ionizing radiation
Arsenic ingestion
?photosensitising drugs Family/personal history of BCC/SCC

41

SCC precursor lesions

Actinic keratoses
Bowen's disease

42

Risk factors for SCC?

Chronic/cumulative sun exposure. Sunbeds.
Immunosuppression (65-250x)
Arsenic /petroleum products/organophosphates/smoking/scars/HPV ?photosensitising drugs
Family/personal history of BCC/SCC

43

SCC predisposing syndromes

XP
Rothmund Thomson syndrome
Bloom syndrome
Werner syndrome
Dystrophic epidermolysis bullosa
Fanconi anaemia

44

Precursor lesions for melanoma

Moles

45

Where are melanomas usually found?

Chest/back (men)
Legs (women)
Palms and soles
Growing under the nails
Eyes

46

Risk factors for melanoma

Risk factors:
Intermittent sun exposure/sunburn. Sunbeds
Ionizing radiation
Immunosuppression
?photosensitising drugs/?heavy metals/?other occupational exposure Family/personal history of CM/BCC/SCC

47

Melanoma predisposing syndromes

XP
Atypical mole syndrome

48

Drugs associated with photocarcinogenesis

Psoralen
Voriconazole
Azathioprine
Vemurafenib

Photosensitising drugs
Immunosuppressants
Topical

49

UV and langerhans cells

UV reduced number of langerhans cells

50

UV and oxidative stress

Increases oxidative stress

51

UV and exogenous compounds

UV interacts with exogenous compounds

52

UV and IL10 and PGE2

UV upregulates inflammatory mediators including IL10 and PGE2