Skin Flashcards
(101 cards)
1
Q
What are the three layers of the skin?
A
- epidermis
- dermis
- hypodermis
2
Q
What are the four layers of the epidermis?
A
- stratum corneum
- stratum granulosum
- stratum spinous
- stratum basale
3
Q
What are the three cells of the epidermis?
A
- kertainocytes
- melanoyctes
- langerhans cells
4
Q
What is the main function of the epidermis?
A
replaces damaged cells by continually producing keratinocytes, and pushing them up through the 4 layers - - this takes 28 days
protects the body from UV radiation by producing melanin
5
Q
Stratum Basale
A
- single layer of keratinocytes
- these undergo division and push up through the stratum spinosum
- melanocytes contain melanin
- this is distributed to the adjacent keratinocytes
6
Q
Stratum Spinosum
A
- anchors cells together by interlocking cytoplasmic processes
- cells are prickle cells
7
Q
Stratum Granulosum
A
- cells undergo enzyme induced
- cells lose their nuclei and organelles
- lipidrich secretions - water sealant
- keratin laid down to mesh the structure together
8
Q
Stratum Corneum
A
- dead cells, flattened cells filled with keratin
- corneocytes are shed from the skin
9
Q
What is the function of the dermis?
A
- strength (collagen and fibroblasts)
- elasticity (eklastin)
specialised structures:
- sweat glands
- hairs
- sebaceous glands
- smooth muscle
- cutaneous lympathics
- nerves
10
Q
What is the function of the hypodermis?
A
- contains nerves, blood supplies and fat
- cushions and insulates the tissue
11
Q
What are the four main functions of the skin?
A
- Production of Vitamin D
- Sensory organ - touch, pain, temperature
- Control of body temperature
- Barrier to protect tissues and organs
12
Q
Production of Vitamin D in the skin
A
- cholesterol in the skin produces Vit D3 (Cholecaciferol) in the presence of sunlight
- Vit D3 converted to Calcidol in the Liver
- Calcidol converted Calcitriol in the Kidney
- Increases calcium levels by producing more carrier proteins for Ca in the blood
13
Q
What are the sources of vitamin D?
A
- sunlight
- oily fish
- eggs
14
Q
What are the conditions associated with a deficiency of Vitamin D?
A
Children: Rickets
Adults: Osteomalacia
15
Q
What are the receptors present in the skin to allow it to act as a sensory organ?
A
- mechanoreceptors (touch)
- thermoreceptors (temperature)
- nocireceptors (pain)
16
Q
How does the skin control body temperature?
A
- vasodilation
- vasoconstriction
- sweat glands secrete water and salt
- a weak insulator
17
Q
How does the skin act as a barrier?
A
corny hard waterproof outer layer to protect from:
- bacteria and toxins
- dehydration
- UV radiation
- mechanical damage and trauma
18
Q
How does the skin initiate an immune response?
A
- Langerhans cells ingest foreign particles
- acts as an antigen presenting cell
- presents the particle to T/B cells
19
Q
How does the skin heal if the injury only affects the epidermis?
A
- where the keratinocytes break away from the stratum basale
- cells enlarge and move across the wound
- growth stops when there is contact inhibition
20
Q
What are the four stages of the skin healing process?
A
- Haemostasis (stop bleeding)
- Inflammatory (clean the wound)
- Proliferative (healing)
- Maturation (scarring)
21
Q
Haemostasis Phase
A
formation of a plug:
- platelets recognise exposed collagen
- release Thromoxane A2
- activated platelets aggregate together to form a plug
vasoconstriction:
- activated platelets release serotonin
- reduces blood supply to minimise blood loss
trapping red blood cells:
- damaged tissue releases thromboplastin
- thromboplastin + calcium = fibrin
- fibrin traps red blood cells
dries to form a scab
22
Q
Inflammatory Phase
A
langerhans cells release inflammatory mediators:
- bradykinin (pain)
- leukotrienes (increases blood flow)
white blood cells move into the area due to increased capillary permeability
- WBCs produces neutrophils to digest bacteria
monocytes move to the wound - mature into macrophages to continue cleaning the wound
23
Q
Proliferative Stage
A
- macrophages initiate this phase
- low oxygen = macrophages release angiogenic growth factors to develop blood vessels
- provides more oxygen
- macrophages also attract granulation tissue to produce new connective tissue
- fibroblasts are activated to produce a collagen network
- myofibroblasts act like muscle to contract and close the wound
- epithelial cells move over the granulation tissue, contact inhibition to stop growing
24
Q
Maturation Stage
A
- collagen re-aligned to improve strength
- collagen strands pull the wound inwards
- extra blood vessels close
25
What are the intrinsic patient factors that will affect wound healing?
- patient nutrition
- skin perfusion
- age
- weight
- co-morbidity including medication
- smoking
26
What are the extrinsic wound factors that affects wound healing?
- moist wound (moist enough for epithelial cells to grow, but not too moist for infection)
- wound temperature
- tissue oxygenation
- pH
- infection delays wound healing
- clean wound surface
27
What is the most common form of eczema?
Atopic
- where there is a common allergy link (Ig E)
- co-presenting symptoms of hay fever and asthma
28
What is the epidemiology of atopic eczema?
- affects all ages, but common in children
- most cases clear by 7/16
- some cases chronic, where it flares up, caused by triggers
- some adults do develop
29
What is the pathophysiology of atopic eczema?
a dysfunctional skin barrier
- altered conversion of keratinocytes to protein/lipid scales
- half of cases traced to the gene for filaggrin
- T helper cell dysregulation involved, linked to Ig E and Mast Cells
this causes
- water loss from the skin, dehydration
- hyper-reactivity to allergens
- infection (staph aureus)
30
What are the risk factors for developing atopic eczema?
- stress
- genetics
- pollen and pets
- rough clothes/dyed clothes/tight fitting
- contact allergens
- extremes of temperatures
- hormones
- skin infections
- certain foods
- house dust mites
- soap and allergens
31
What are the symptoms for diagnosing atopic eczema?
- itching
- inflamed, dry, red skin
- papules (raised red bumps)
- papules coalesce to form plaques (secretion of sebum)
- weeping, crusted, blistered, scaling, thick
- sleep disturbance
- onset in a young age
- flexures
- asthma?
- family member?
32
What are the different areas eczema can affect?
young children:
- face, cheeks, scalp, chin
older children:
- flexures, wrists, ankles
adults:
- & the hands
33
What are the characteristics of mild, moderate, severe and infected eczema?
mild:
- dry skin, itching, some redness
moderate:
- dry skin, itching, redness, thickening, more areas affected
severe:
- widespread symptoms, thickening, bleeding, oozing
infected:
- weeping, crusted, pustule and possibly systemic symptoms
34
What are the treatments for mild eczema?
- emollients
| - mild topical steroid if inflamed skin
35
What are the treatments for moderate eczema flare ups?
- increase emollient use
- moderate potency topical steroid
- trial of non-sedating antihistamine
- occlusive bandages
36
What are the treatment options for moderate eczema between flares?
- low potency steroid, intermittent use
| - topical calcineurin inhibitors
37
What are the treatments for severe eczema?
- increase emollient use
- potent topical steroid
- non-sedating/sedating antihistamine
- topical calcineurin inhibitor (between flares)
- oral steroids
- bandages
- phototherapy
38
What are the treatments for infected eczema?
oral antibiotics
- flucloxacillin
- erythromycin
39
What are the different types of emollient?
```
light:
- E-45
- Diprobase
moderate:
- oilatum
- hydrous cream
greasy:
- 50% white soft
- liquid epaderm
```
40
What are examples of low potency steroid creams?
hydrocortisone
- 0.1
- 0.5
- 1
- 2.5
41
What are examples of moderate potency steroid creams?
- clobetasone butyrate 0.05 (EUMOVATE)
| - betamethasone valerate 0.025% (Betnovate RD)
42
What are examples of potent steroid creams?
- betamethasone valerate 0.1% (Betnovate)
| - betamethasone diproprionate 0.05%
43
What are examples of very potent steroid creams?
- clobetasol propinate 0.05%
44
What are the counselling points for steroid creams?
- spread thinly using FTUs
- use the next step down steroid for sensitive areas (neck/face/flexures/genitals)
- maximum use 7 - 14 days
- maximum use 5 days on sensitive areas (more absorption across thinner skin)
- continue 48 hours after inflammation has reduced
- OD/BD, short periods of time
- apply 30 minutes after emollients
45
What are the counselling points for emollients?
- use regularly and liberally, even when you don't have flares
- apply emollients before steroid to increase penetration
- avoid sharing tub preparations - pump
- do not use aqueous cream
- one doesn't work try another
- use greasier preparations at night
- flammable warnings
- don't rub in, stroke in
- gently dry skin after washing and apply to trap moisture
46
What are the other counselling points when treating asthma?
- don't scratch the skin, cut nails/mittens, rub area instead
- link to other conditions?
- avoid exposure to triggers
- recognise flares + treat promptly
- diet alteration?
- discard old topical products to avoid cross-contamination
47
What are example of non-sedating antihistamines?
- cetirizine
- loratidine
- fexofenadine
48
What is an example of a sedating antihistamine?
- chlorphenamine
49
How often should treatment be reviewed in asthma?
- review steroid/tacrolimus use every 3 - 6 months
50
What is the most common type of psoriasis?
- vulgaris
- chronic, inflammatory disorder of the skin and joints
- systemic condition
51
What is the epidemiology of psoriasis?
- mainly Caucasians
| - less common in children (15 - 25 years), then 55 - 60
52
What is the pathophysiology of psoriasis?
inflammatory cells in all layers of psoriatic skin
- T Cells
- TNF alpha
- Interleukins
cause hyper-proliferation (large turnover of cells) and vascular changes (may bleed on scratching)
53
What are the risk factors of psoriasis?
- obesity
- smoking
- alcohol
- genetics - huge family link
- hormones (pregnancy - protective factor, puberty/menopause risk factors)
- medications
- skin injury
- stress
- infection
54
What are the symptoms of psoriasis?
- red plaques, with overlying white scale
- commonly affects buttocks, lower back, scalp, elbows, knees, nails
- thick, scaly skin
- may bleed if scales scraped off
55
What are the complications of psoriasis?
- psoriatic arthritis, screen for symptoms
- depression, anxiety
- metabolic syndrom & CVD
56
What are the treatments for psoriasis on the trunk and limb?
- vitamin D analogues
- & potent corticosteroid for 4 weeks (will take 1 - 2 weeks to work)
- coal tar if these aren't effective (avoid if allergic to aspirin, apply 1/7) - takes 3 - 4 weeks to work
57
What are the treatments for psoriasis on the scalp?
- potent corticosteroid (try a different formulation if not effective) for 4 weeks
- try a formulation with salicylic acid to remove scales THEN
- &/ vitamin D analogue (combination better than each alone)
58
What are the treatments for psoriasis on the face, flexures and genitals?
- mild-moderate steroid 2 weeks
- DO NOT USE vitamin D analogue
- calcineurin inhibitor (Tacroline)
59
What makes psoriasis 'severe'?
- if over 10% of the body is affected, 1% = one palm of the hand
- significant distress/impairment
- failure of treatment
60
What are the treatments for mild psoriasis?
- emollients
- topical corticosteroid (potent)
- tacrolimus (calcineurin inhibitor)
- coal tar /dithranol
61
What are the treatments for moderate psoriasis?
- all of mild psoriasis
- phototherapy
- oral methotrexate/ciclosporin
- oral acitretin
62
What are the treatments for severe psoriasis?
- add biological agent
| - apremilast
63
What are examples of Vitamin D analogues?
- do not use on sensitive areas
- Calcipotriol (Scalp solution)
- Calcitriol
- Tacalitol (lotion)
all of these are ointments too
64
What are the counselling points of Vitamin D analogues?
- can cause skin irritation
- can cause photosensitivity
- sun cream
- avoid sunbeds
- will take 1 - 2 weeks to work
65
What is the advice for flare treatment in psoriasis?
- treat in 4 week blocks
- then break for 4 weeks
- use Vit D analogues in between flares
- report joint symptoms immediately
- avoid scratching and picking
66
What is the most common type of acne?
vulgaris
67
What is the epidemiology of acne?
- teenagers most common
- affects more men than women when younger
- affects more women than men when older
68
What does the pilosebaceous follicles involve in the pathophysiology of acne?
- inflammatory action
- increased production/altered composition of sebum (due to androgens in puberty)
- growth/activity of Cutibacterium acnes within sebum in hair follicles (more sebum available to grow)
- keratonicyte proliferation stimulated by Cutibacterium acne, blocked and inflamed
69
What is comedogenesis?
blocked follicles
70
What is hypercornification?
hardening of the skin
71
What does comedogensis and hypercornification lead to?
- blockage of the pilosebaceous follicles and acne lesions
- closed comedones (whiteheads)
- open comedones (blackheads - where the melanin reacts with the sun)
72
What are the risk factors of acne?
- family members
- high glycemic index foods - increases androgens
- medications
- polycystic ovary syndrome - linked to increased androgens
- smoking
- stress
- cosmetics (need non-comedogenic makeup)
73
What are papules?
small red raised bumps
| - less than 5mm in diameter
74
What are pustules?
same as papules but with yellow/white filled fluid
| - less than 5mm in diameter
75
What are nodules?
harder, more painful, deeper spots that can lead to scarring
| - over 5mm in diameter
76
What are cysts?
deep, large, puss-filled spots
| - over 5mm in diameter
77
How is the severity of acne determined?
- large area affected
- scarring/lesions
- treatment failure
- severe distress
78
What is the treatment for mild-moderate acne?
- topical retinoid
- benzoyl peroxide (antibacterial)
- azelaic acid (milder acne, not as potent)
- topical antibiotic
- emollient (oil free/non-comedogenic)
treat for 6 - 8 weeks then refer to GP
79
What is an example of a topical retinoid?
- adapaline 0.1% gel/cream
- isotretinoin (only for 18+)
- OD/BD
- disrupt & inhibit formations of comedones
- anti-inflammatory
80
What topical antibiotic is used for mild-moderate acne?
- clindamycin with BPO
| - clindamycin with BPO and Retinoid
81
What are the treatments moderate severity acne?
- oral antibiotic + topical retinoid
- add BPO
- maintenance treatment long term (BPO/Retinoid/Azelaic Acid)
treat for 6 - 8 weeks, repeat courses but not recommended as long-term treatment
82
What are the oral antibiotics used for moderate acne?
- doxycycline
- lymecicline
- erythromycin
83
What are the counselling points for someone with acne?
- don't over clean the skin, may dry out skin
- don't pick/squeeze lesions, scarring
- use non-comedogenic/no oil products
- BPO can bleach hair and clothing
- skin irritation, can reduce application frequency or switch products
- avoid sun beds BPO/retinoids/oral antibiotics
- avoid triggers
- avoid contact with eyes and mucous membranes
- avoid retinoids/oral antibiotics in pregnancy
- apply to whole affected area
- gels - apply after washing, wash off after a few hours
- washes - apply after washing, wash off after few mins
- retinoids - pea sized amount to area, then wash off after 30 - 60 mins
84
What is Isotretinoin?
- an oral retinoid
- used for acne unresponsive to topical treatments/antibiotics
- specialist treatment
- 16 week course
- can repeat the course in a relapse
85
What are the actions of isotretinoin?
- reduces skin sebum secretion by 90% after six week
so also see a reduction in C acnes concentrations
- decreases hyperkeratinisation
so this interferes with comedogensesis, no blocking of particles
- anti-inflammatory properties
86
What are the risks of using isotretinoin?
TERATOGENIC - PPP, pregnancy prevention programme
- effective contraception 1 month before and 1 month after treatment
- effective contraception = CIUD/IUD/Implant
DEPRESSION/ANXIETY/SUICIDAL IDEATION
- collect psychiatric history, stop if mental health deteriorates
IMPAIRED NIGHT VISION
- sensitive to headlights
DRY SKIN/JOINT PAIN as it reduces secretions
FRAGILE SKIN
- need UV protection SPF 50
- no hair removal treatments during or 6 - 12 month after
LIVER RISKS
HIGH BLOOD LIPIDS
87
What are the two types of phototherapy in psoriasis?
Narrowband UVB (First Line)
- better tolerated
- 2/3 times a week
Psoralen and UVA
- psoralen 2 hours before UVA exposure
- UVA exposure activates psoralen
- inhibits basal cell proliferation
- 3 times weekly
- clears in 5 - 6 weeks
88
What are the adverse effects of phototherapy in psoriasis?
- teratogenic (contraception)
- premature skin ageing
- skin pigmentation
- cataract formation (UVA eye protection)
would need regular skin examinations for pre-malignant changes
89
What is acitretin used for?
- moderate psoriasis
| - synthetic retinoid (similar to isotretinoin)
90
How does acitretin work?
- decreases hyperkeratinisation and normalises cell proliferation, differentiation and cornification
- longer half life
- so, treatment is longer than 16 weeks
91
What are the risks of acitretin?
- contraception for 3 years after, due to half life
- CI in hyperlipidaemia
- Hepatotoxic (monitor liver function every three months, every 2 weeks to start)
- Cannot drink alcohol as alcohol increases serum levels of the drug
92
What is methotrexate?
a folic acid antagonist
- used in moderate psoriasis and eczema
- takes 1 - 3 months for full effect
93
How does methotrexate work?
- inhibits dihydrofolate reductase
- blocks DNA synthesis
- this slows down basal cell proliferation in psoriasis
- anti-inflammatory action in eczema
94
What are the risks of methotrexate?
- liver cirrhosis (LFTs, every month, then 3 months)
- blood disorders (FBCs every week, then every month)
- GI symptoms
so give folic acid once weekly same as methotrexate, but on a different day to the methotrexate
- alopecia
- family planning
- infection risk (dampens down the immune system)
- avoid trimethoprim and NSAIDs
95
What is ciclosporin?
- used in psoriasis and eczema
- 2 - 4 months
- BD
96
How does ciclosporin work?
- IL 2 blocked
- Blocks proliferation of T lymphocytes and cytokines (anti-inflammatory, eczema)
- Blocks proliferation of keratinocytes (psoriasis thickening)
97
What are the risks of ciclosporin?
- Nephrotoxic
- Hypertension
- Teratogenic (but can be used last line in pregnancy if needed)
- Immunosuppressant - infection risk
- Avoid grapefruit juice
98
What are biologics?
- treatment for severe psoriasis
- anti TNF monoclonal antibodies (mAb)
- highly effective with responses seen in 6 weeks
- therapy continued 6 months - 2 years
- can switch between mAbs if needed, if one isn't working try another
99
What are the risks of biologics?
increased risk of infection
(TB concerns, no raw/part cooked meat, fish, eggs or dairy)
cardiovascular risk
worsening of underlying neurological disease
cancer risk in patients
100
What biologic is used in the treatment of eczema?
Dupilumab
- inhibits activation of T helper cells
- inhibits expression of filaggrin
101
What is the risk of dupilumab?
- predisposes to worm infection
- dose every 2 weeks
- review at 16 weeks
- only use if no response/intolerance to all other treatments
