Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
33 Cards in this Set
- Front
- Back
|
Which UV wavelengths damage which layers of the skin and how? |
UV-A - to the dermis - ageing and wrinkling UV-B - to the skin surface - Burning |
|
|
How does UV directly damage DNA? |
Produces thymidine dimers |
|
|
How does UV indirectly damage DNA? |
Creates free radicals leading to oxidative DNA damage |
|
|
Why is skin cancer so common in the UK? |
Tanning and sunbeds, lack of sun cream |
|
|
What causes benign moles (melanocytic nevi) |
Congenital or acquired More common in sun exposed areas |
|
|
What are the ABCDE's of moles? |
Asymmetry Border Colour Diameter Evolving |
|
|
What is a melanoma? |
Tumour of the melanocyte 50% from existing moles, 50% from normal skin |
|
|
What are some intrinsic risk factors for melanomas? |
Fair skin - melanin levels Many/atypical moles - increased melanocyte conc Fx - CDKN2A-p16 tumour suppressor gene |
|
|
What is the most common melanoma? |
Superficial spreading melanoma |
|
|
What does a superficial spreading melanoma look like and what causes it? |
Grow in horizontal growth phase like a puddle Can invade and spread Intermittent sun exposure |
|
|
What is a Lentigo Maligna Melanoma |
Primarily grow in horizontal growth phase like a puddle Rarely invade and spread Continuous sun exposure |
|
|
What is a Nodule Melanoma |
Primarily grown in vertically Burrowing mole Frequently invade and spread |
|
|
What is a Nail Melanoma? |
Grow both horizontally and vertically Frequently ignored and misdiagnosed by pts Frequently invade and spread |
|
|
What is an Amelanotic melanoma? |
Grow mainly vertically Frequently misdiagnosed and ignored by pts Frequently invade and spread |
|
|
What are some typical melanoma mimics? |
Dysplastic melanocytic nevus - benign moles Seborrheic keratosis - waxy, scaly, slightly elevated, cause not known (not thought to be sun induced) Solar lentigo - harmless patch of darkened skin, excessive melanin Dermatofibroma - benign fibrous nodule, reaction to insect bites |
|
|
Treatment and outcome for non-invasive melanoma? |
Surgical excision - 98% curative |
|
|
Treatment and outcome for invasive melanoma? |
Pharmacological intervention - 18% 5ys Radiotherapy/dacarbazine or B-raf inhibitors |
|
|
What is the presentation of atopic dermatitis (eczema)? |
Acute skin rash (red, dry, itchy) Typically presents on flexor surfaces, exposed skin |
|
|
What type of disorder is eczema? |
Hypersensitivity disorder |
|
|
What is the mechanism of action of eczema? |
Inflammation due to allergen makes skin 'leaky' Allows in more of the allergen Allows more water to escape Skin becomes dry and itchy/damaged Leads to a cycle of scratching > allergy mediated inflammation > dry skin |
|
|
Clinical consequences of eczema? |
Recurrent infections Cellulitis Sleep disturbances Painful movement Anxiety Depression Cardiovascular issues |
|
|
What causes Cellulitis? |
Typically group A strep but all staph |
|
|
What is Psoriasis? |
Chronic skin plaque (red, flaky, crusty) covered by silvery scales Elbows, knees, scalp, lower back Cause not fully known by also hypersensitivity disorder |
|
|
Mechanism of action of psoriasis? |
1) Promoted keratinocyte cell growth 2) H2O leak 3) Immune mediation leads to dilated vessels bringing in more immune cells |
|
|
Clinical consequences of Psoriasis? |
Recurrent infections Sleep disturbances Inhibited movement Anxiety Depression Cardiovascular 25% developed psoriatic arthritis |
|
|
Treatment for psoriasis? |
Topical corticosteroids - reduce inflammation Phototherapy - UV light kills hyperactivated lymphocytes |
|
|
What is Actinic Keratosis? |
Precursor lesion to squamous cell carcinoma Risk factor - Chronic sun exposure |
|
|
Treatment for Actinic Keratosis? |
Pharmacological intervention - imiquimod - 99% cure Untreated - 0.5% py progress to squamous cell carcinoma |
|
|
What is Squamous Cell Carcinoma? |
2nd most common type of skin cancer Risk factor - long term sun exposure and immunocompromised |
|
|
Treatment for Squamous Cell Carcinoma? |
Non-invasive - Excision 99% cure Untreated - 0.5%py progress to invade/spread Invasive - Chemo - 15% 5yr survival |
|
|
What is Basal Cell Carcinoma? |
Most common type of skin cancer Risk factor - intermittent sun exposure Nodular, superficial and infiltrative BCC |
|
|
Treatment for BCC? |
Excision 99% cure Invasion is extremely rare True invasion of infiltrative is <0.5% Sonic Hedgehog inhibitor for for infiltrative |
|
|
|
|
