WEEK 2 Flashcards
1
Q
advantages of topical treatments?
A
- direct application
- reduced systemic effects
2
Q
disadvanates of topical
A
tim consuimgn
correct dosage
3
Q
what is a cream?
A
- semisolid of oil in water
- contain emilsifier and preservative
- non greasy
- high water content
- cool and moisturise
4
Q
what is an ointment?
A
- semi solid grease/oil
- no preservative
- occlusive and emollient
5
Q
what is a lotion?
A
- liquid formualtion
- suspension or solution of medication in water, alcohol or other liquids
- treat scalp or hairy areas
6
Q
what is a paste?
A
- stiff
- greasy
- contain finely powdered material
- protective, occlusive, hydrating
7
Q
advantage of using a foam?
A
- increased penetration of active agents
- can easily spread over large areas of skin, no greasy oil/film
8
Q
main classes of topical therapies?
A
- emollients
- topical steroids
9
Q
why re emollients used?
A
- prescribed for all dry scaley conditions
- enhance rehydation of epidermis
- need frequent application
10
Q
how much emollient should be prescribed per week?
A
300-500g per week for extensive asthma
- apply frequently
11
Q
what is one risk when using an emollient?
A
highly flammable
- smoking is not reccommended
12
Q
what is the term given to very dry skin?
A
xerotic
13
Q
give 4 possible side effects of topical steroids
A
- v
14
Q
mode of action of topical steroids?
A
- reduce inflammation
- cause immune suppression
- vasoconstrictive
- anti proliferative
15
Q
give a mild topical steroid?
A
hydrocrotisone
16
Q
give a name of a potent steroid?
A
- betnovate
- mometasone
- valerate
- betamethasone
17
Q
uses of topical steroids?
A
- eczema
- psoriasis
- other non-infective inflammatory dermatoses
- keloid scars
18
Q
how much steroid should be applied to the whole body?
A
20-30g tube for one week
19
Q
side effects of topical steroids?
A
- steroid rosacea
- perioral dermatitis
- thinning of the skin
- purpura
- stretch marks
- may worsen or mask infections
- systemic absorption
- tachyphylaxis
- rebound flare of disease
- glaucoma and cataract
20
Q
name an ultra potent steroid
A
clobetasol propionate
21
Q
what effects do antiseptics have?
A
- bacteriocidal affects
22
Q
give an example of an antiseptic
A
- providone iodine skin cleanser (betadine)
- hibitane, savlon
- triclosan
- hydrogen perooxide
23
Q
when would antibiotics be used?
A
- acne/roascea
- skin infection
- infected eczematous process
- otitis externa
24
Q
name conditions in which topical antifungals would be used
A
- candida (thrush)
- dermatophytes (ringworm)
- pityriasis versicolour (use cream or shampoo)
25
name some good antipruritics
* menthol
* capsaicin (from red chilli peppers)
* camphor / phenol
* crotamiton
26
what are keratolytics used for?
used to soften keratin
e.g....
* viral warts
* hyperkeratotic eczema / psoriarsis
* corns / calluses
27
side effects of topical therapies?
* burning or irritation
* contact allergic dermatitis
* local toxicity
* systemic toxicity
28
what cell type lines the normal epidermis?
* epidermis-stratified keratinising squamous epithelium
29
function of langerhans cells in epidermis?
* act as sentinels monitoring environment for antigens
* important in initiating inflammation
* located in upper and mid-epidermis
* dendritic cells
30
which part of the dermis are the appendages and pilosubaecous usints found?
in the reticular dermis
31
where are the malnocytes?
the purple dots with the white halos around them
* highly dendritic
* pigment synthesisers
* act as a UV barrier
32
what is acanthosis?
increased thickness of the epithelium (to basal layer) really just hyperplasia
33
what is parakeratosis?
perisistence of nuclei in the keratin layer
34
what is hyperkeratosis?
increased thickness of keratin layer
35
what is papillomatous?
irregular epithelial thickening
36
what is spongiosis?
* oedema fluid between squames appears to increase prominence of intercellular prickles
* if severe filled by oedema flui will develop
37
what are the 4 main recation patterns of inflammatory skin disease?
* spongiotic intraepidermal oedema (e.g. oedema)
* psoriaform-elongation of the rete ridges (e.g. psoriasis)
* lichenoid-basal layer damage (e.g. lichen planus and lupus)
* vesiculobullous-blistering (e.g. phemphigoid, phemphigus and dermatitis herpetiformis)
38
* conditions characterised by damage to the basal epidermis
* protypic condition is lichen planus
* itchy flat topped violaceous papules
lichenoid disorders
39
what does lichen planus histology look like?
* irregular saw tooth acnthosis
* hypergranulosis and orthohyperkeratosis
* band like upper dermal infiltrate of lymphocytes
* basal damage with formation of cytoid bodies
40
* blisters are the primary feature of this disease
* caused by disroders of the immune system
Examples
* pemphigus
* bullous pemphigoid
* dermatitis herpetiformis
immunobullous diseases
41
pathology behind pemphigus?
loss of integrity of epidermal cell adhesion
42
what is pemphigus vulgaris?
* autoimmune condition
* IgG auto-antibodies made against desmoglein 3 (like a glue in the eoidermis)
* immune comlexes form on cell surface disrupting desmosome attachments
* end result is acantholysis
43
symptoms of pemphigus vulgaris?
* involves skin (scalp, face, axillae, groin, trunk)
* may affect mucosa (e.g. mouth, resp. tract, extensive mucosal involvement may be fatal)
* produces fluid filled blisters which rupture to form shallow erosions
44
what is the histological hallmark for dermatitis herpetiformis?
* papillary dermal microabscesses
45
what antibody should be looked for in dermatitis herpetiformis?
IgA in dermal papillae
46
give the aetiology of acne?
1. increased androgens at puberty
2. increased androgen sensitivity of sebaceous glands]keratin plugging of pilsubaecous units
3. infection with anaerobic bacterium corynebacterium acnes
47
what is rosacea?
* scaley erythamatoeus eruptions
* patchy inflammation with plasma cells
* pustules
* demodex mite in subaecous duct
48
type 1 allergy
* causes an immediate reaction (minutes - 2hrs)
* may routes of exposure
* must have a consistent reaction with every exposure
49
what must occur with all allergies
you must be sensitised to the allergy first
50
common clinical presentations of allergies?
* urticaria
* angioedema
* wheezing/asthma
* anaphylaxis (circulartory collapse)
51
investigations of allergies?
* history
* specific IgE
* skin prick or prick prick testing
* challenge test
* serum mast cell tryptase level
52
manageeent of allergies?
* allergen avoidance
* orevent affects of mast cell activation (anti-histamines)
* anti-inflammatory agent (corticosteroid)
* adrenaline autoinjector (for anaphylaxis)
53
type IV allergy
* delayed hypersensitivity
* antigen specific
* T cell mediated
* allergic contact dermatitis
* onset reaction typically 24-48 hrs after exposure
54
what is done when bacteria is suspected?
put swab on agar plate
55
* gramp oisitive cocci in clusters
* aerobic and faculatively anaerobic
* 2 important ypes (staph. arueus: coagulase positive + coagulase negative staph)
staphylococcus sp.
56
only ever prescribe or take a swab when???!!
THERE IS A CLINICAL SIGN OF INFECTION
* dont assume just because there is a culture swab carried out
57
* common human pathogen
* prodces enzymes including coagulase, an enzyme that clots plasma
* distinguishes it from all other staph. species^^
* causes wound, skin, bone and joint infections
* flucloxacillin reccommended to treat
* resistent starins (methicillin resistant)
* some strains produce toxins
staphylococcus aureus
58
what does methiccilin resistent staph aureus mean?
**flucloxacillin resistent**
use e.g.
* doxycycline
* co-trimoxazole
* vancomycin
59
what does it mean by staph. epidermidis being a skin commesnal?
NOT PATHOGENIC
60
when should yu swab a leg ulcer
when there is high suspcicion of infection as there are usually commensals living there whcih is okay
61
what happens if you think a patient has measles?
in negative pressure room
need to be isolated
62
what is urticaria?
erythema with a well defined edge
63
what does eczema look like?
ill defined, scaley
64
give 3 cutaneous examples of type 1 hypersensitivity
* urticaria (red wehals caused by blood vessel dilation + leakage into surrounding tissue)
* angio-oedema (swelling of subcutaenous tissues)
* anaphylaxis
65
cutaneous examples of type 4 (delayed) hypersensitivity?
66
give the factors increasing the potential of topical steroids to cause side effects
67
side effects of steroids?
* contact allergy to hydrocortisone
* acneifrom eruptions
* tachyphylaxis
* pigmentary changes
* poor wound healing
* modification of existing disease
* unstable pustular psoriasis
* steroid roascea
* atrophy, bruising
* gaucoma
* hirsutism
* poor owund healing
* striae (stretch marks)
* growth retardation (systemic effect)
68
what can be done to reduce the risk of side effects from steroids?
* dont use topical steroids where they wnt work
* use least potent preparation that is effective
* know quanitites required for appropriate use
69
