Dermatology Flashcards
1
Q
If someone presents with an ulcer, how can you differentiate between the different types?
A
venous - painful, worse on standing, usually over medial malleolus, LARGE SHALLOW IRREGULAR BORDER
+ leg oedema, brown pigment
arterial - painful, worse when leg elevated or at night time, usually over trauma or pressure sites, SMALL SHARPLY DEFINED DEEP ULCER
+ cold skin, absent pules, loss of hair
neuropathic- painless, abnormal sensation, usually over pressure points (e.g. soles, heels, toes), variable size, GRANULATING BASE, deformity (claw foot, Charcot joint, pes cavus)
+ peripheral neuropathy
2
Q
What are the risk factors for venous ulcers?
A
history of venous disease e.g. DVT, varicose veins
3
Q
What are the risk factors for arterial ulcers?
A
history of arterial disease e.g. atherosclerosis diabetes poor footwear obesity poor mobility smoking
4
Q
How are arterial ulcers diagnosed?
A
ABPI <0.8
+ doppler ultrasound
+ angiography
5
Q
What are the risk factors for neuropathic ulcers?
A
diabetic neuropathy!!!
neurological disease
6
Q
How are venous ulcers managed?
A
compression banding
7
Q
how are arterial ulcers managed?
A
- lifestyle measures - stop smoking, weight loss, healthy diet
- good wound care and dressing
- skin grafting
- vascular reconstruction e.g. bypass, angioplasty
8
Q
How are neuropathic ulcers managed?
A
- wound debridement
- good nutrition, footwear
- optimise diabetes control
9
Q
What is a basal cell carcinoma?
A
a slowly growing, locally invasive malignant tumour of the epidermal keratinocytes (rarely metastasise)
10
Q
What are the risk factors for basal cell carcinoma?
A
sun exposure ** history of severe sunburn elderly type 1 skin type immunosuppression
11
Q
Describe the appearance of a basal cell carcinoma?
A
most common is NODULAR - small, skin coloured papule, PEARLY ROLLED EDGE, necrotic centres (= rodent ulcer), can bleed
12
Q
List the morphological classification types of basal cell carcinomas?
A
- nodular *
- superficial
- cystic
- morphoeic
- keratotic
- pigmented
13
Q
How are BCC managed?
A
surgical excision **
OR mohs micrographic surgery (excise lesion and tissue borders bit at a time until specimens free of tumour), cryotherapy, curettage and cautery
14
Q
Describe a squamous cell carcinoma
A
locally invasive malignant tumour of epidermal keratinocytes (can metastasise)
15
Q
List the risk factors for squamous cell carcinoma
A
sun exposure smoking pre malignant conditions untreated e.g. actinic keratosis, Bowens disease chronic inflammation e.g. wounds, ulcers immunosuppression
16
Q
Describe the appearance of a squamous cell carcinoma
A
keratotic - scaly, crusty, ill defined, tender nodule on sun exposed areas, can ulcerate
17
Q
How are squamous cell carcinomas managed?
A
biopsy and CT/MRI (mets)
surgical excision ** (or mohs micrographic surgery)
OR radiotherapy if spread or very large non resectable tumours
18
Q
Define actinic keratosis
A
pre malignant condition where there is dysplastic proliferation of atypical keratinocytes on sun exposed areas
19
Q
Describe the appearance of actinic keratosis
A
crumbly, yellow, scaly crusty macules on sun exposed areas - often on head, face
20
Q
Describe the premalignant stages of SSC
A
- actinic keratosis = atypical keratinocytes
- Bowens = full thickness keratinocytes “carcinoma in situ”
- SSC = invaded through BM
21
Q
How can actinic keratosis be managed?
A
- if mild, no treatment and watch and wait
- diclofenac gel - daily for 2-3 months
- fluorouracil 5% cream (topical chemotherapy)
- imiquimod 5% cream
- cryotherapy
- surgical excision - if unresponsive or suspect malignant
22
Q
Define malignant melanoma
A
invasive malignant tumour of the epidermal melanocytes, which can metastasise
23
Q
List the risk factors for malignant melanoma
A
sun exposure **
type 1 skin type
history of multiple atypical moles
FH of melanoma
24
Q
What are the most common types of malignant melanoma
A
- SUPERFICIAL SPREADING** - most common, slowly enlarging, commonly on lower limbs, irregular border
- NODULAR - most aggressive, invades deeply, grows rapidly and metastasises
- LENTIGO - common in elderly
- ACRAL LENTIGINOUS - common in elderly and black/asian skin
25
How are malignant melanomas described?
A- asymmetrical
B- borders irregular or blurred
C- colour change e.g. black, brown, "blue"
D- diameter >6mm
E- elevated, shape change
S- symptoms e.g. bleeding, itching, different to other moles
26
How is a suspected malignant melanoma managed?
1. referred to dermatologist under 2 week wait
2. surgically excised - need 2 mm margin of normal skin around lesion + sentinel node biopsy
+/- radiotherapy or chemotherapy for metastatic disease or cannot operate
27
Which score is used to estimate the recurrence of melanomas?
BRESLOW THICKNESS - invasion depth is single most important prognostic factor
<0.75MM = low risk
0.75-1.5MM = medium risk
>1.5MM THICK = HIGH RISK
28
List preventative measures of skin cancers
wear sunscreen
wear a hat, cover up during hot times of the day (11am-3pm)
advise patients to monitor skin changes
29
Describe melanocytic naevi
benign skin lesion due to local proliferation of melanocytes
occurs in infancy, childhood, adolescence
asymptomatic
30
Describe the appearance of congenital melanocytic naevi
large, irregular border, pigmented, hairy
31
How can melanocytic naevi be removed?
excision biopsy, shave biopsy or laser
32
Describe the appearance of seborrheic wart
"stuck on" appearance of a warty, greasy papule with well defined edges
common on face and trunk and in elderly
33
How can seborrheic warts be removed?
1. cryotherapy
2. shave biopsy
3. curettage
34
What is the cause of eczema?
most common type is atopic eczema - caused by positive family history of atopy e.g. asthma, eczema, allergic rhinitis
35
List possible triggers of eczema
infection
stress
allergens e.g. chemical (clothes washing detergent, soap, perfumes), pets, dust
heat / sweating
36
Describe the appearance of eczema
** itchy erythematous dry scaly plaques **
common on flexor surfaces as adults
scratching can cause excoriations and lichenification
nail pitting
37
How is eczema managed?
1. avoid exacerbations, apply emollient creams
2. topical therapies
- topical corticosteroids (hydrocortisone 0.5-2.5% -> betnovate)
- topical calcineurin inhibitors e.g. tacrolimus
3. oral steroids (prednisolone), anti histamines for symptomatic relief, antibiotics for bacterial infections
4. phototherapy
38
How should emollients be used in eczema?
emollients should be used liberally and frequently (at least 3x a day)
e.g. E45, diprobase, dermal
in the form of cream, gel, ointments
can be used to replace soap
39
Describe the pathophysiology of acne
1. androgen mediated increase in sebum production
2. formation of micro commodore and keratin plug
3. colonised with propioni bacterium acne
4. causes inflammation
40
How does both mild and severe acne present?
mild acne = NON inflammatory -> open (black) and closed (white) comeodones
severe acne = inflammatory -> pustules, papules -> nodules, cysts -> erythematous , ice pick scarring
41
what are the possible complications of acne?
post inflammatory hyperpigmentation
scarring
psychological/ social effects
acne fulminant (severe acne + fever ->hosp admission -> oral steroids)
42
How can acne be treated?
1. topical retinoids e.g. adapolene (Differin), isotretinotic gel
targets micro comeodone
2. COCP e.g. Yasmin
targets sebum production
3. topical benzoyl peroxide 5% e.g. acnecide cream
targets bacteria and inflammation
4. topical antibiotics e.g. DUAC (topical BPO + clindamycin)
5. oral antibiotics + creams e.g. doxycycline for 3 months
erythromycin if pregnancy
6. Isotretinoin e.g. roacutane
43
What is psoriasis?
chronic inflammatory skin disease due to hyper proliferation of keratinocytes and inflammation
44
List and describe the different types of psoriasis
1. chronic plaque psoriasis - most common, symmetrical well defined red plaques with silvery scale
2. Guttate- multiple small "raindrop drop" plaques, usually trunk, upper arms, thighs
3. flexural - red plaques under body folds (differential: fungal infection)
4. pustular - on palms, yellow brown pustules
5. erythrodermic - redness all over body + systemic upset (fever, dehydration) - medical emergency!! can be caused by steroid withdrawal
45
list precipitating factors of psoriasis
```
stress
depression, anxiety
infection
alcohol
drugs e.g. lithium, NSAIDs, beta blockers
```
46
Describe the presentation of psoriasis
erythematous (red) scaly plaques
itchy, painful
common on EXTENSOR surfaces
nail changes: pitting, oncolysis, thickening
auspitz sign: scratch and removal of scales causes bleeding
47
What are the complications of psoriasis
```
psoriatic arthropathy !! (8%)
depression, anxiety, psychological distress
CV disease, high BP
other autoimmune conditions
Erythroderma
```
48
How is psoriasis managed?
1. avoid precipitating factors, apply emollient (reduces scales and pruritus)
2. 1st line = topical vitamin D analogues e.g. calcipotriol (dovonex) + topical corticosteroids e.g. betnovate once daily for 4 weeks
3. use vit D analogue twice daily if ineffective (need a 4 week break between steroid use)
4. oral tar preparations
5. phototherapy (UVB light) or PUVA
6. methotrexate - if systemic involvement
49
list the differentials for hair loss
1. ANAGEN HAIR LOSS = decreased growth of hair
e. g. alopecia areata, chemotherapy, congenital
2. TELOGEN HAIR LOSS = shedding of hair
e. g. weight loss, stress, medications (COCOP, anti coagulants, anti convulsants)
3. MALE PATTERN ALOPECIA
4. SYSTEMIC DISEASES
e. g. iron deficiency anaemia, hypothyroidism, SLE
5. INFLAMMATORY SKIN CONDITIONS
e. g. localised scleroderma, bacterial infections
6. CONGENITAL HAIR LOSS
7. DERMATOLOGICAL CONDITIONS
e. g. psoriasis, atopic dermatitis, tinea capitis infection
50
Define alopecia areata
>1 round bald patches which appear suddenly (hair will regrow in 50% within 1 year)
51
How is alopecia areata caused?
autoimmune disorder **
triggers can also cause e.g. emotional stress, trauma, hormonal change, viral
52
List the types of alopecia
patchy alopecia - bald patches
alopecia totalis - all of hair on scalp lost
alopecia universalis - all hair on body lost
ophiasis - pattern of alopecia affecting occipital and lateral scalp
diffuse alopecia areata - sudden diffuse thinning of hair of scalp
53
How can you try and treat alopecia?
no cure but try...
| topical steroids, minoxidil solution, dithranol ointment
54
What is bullous pemphigoid and how is it caused?
= a blistering skin condition affecting the elderly
autoimmune condition where there is subdermal split in the skin
55
How does bullous pemphigoid present?
tense fluid filled blisters on the skin
itchy
can be preceded with a non specific rash
common on trunk and limbs and around flexures but MOUTH SPARED
56
How is bullous pemphigoid managed?
1. refer to dermatologist and skin biopsy (immunofluorescence shows IgG and C3 at the dermoepithelial junction)
2. wound care dressings, monitor for signs of infection
3. oral steroids ** if widespread (topical if small)
57
how is urticaria 'hives' caused?
```
idiopathic
food e.g. nuts, shellfish, seeds, dairy
drugs e.g. penicillin, contrast media, morphine, ACE-I
insect bite
viral or parasitic infections
cold/ sun exposure
```
58
What is the main inflammatory mediator of urticaria?
HISTAMINE released from skin mast cells
causes a local increase in permeability of capillaries and small venules so get a red rash
59
How does urticaria present?
pink/ red/ white "wheals" on the skin - individual lesions can disappear within a day but continue for weeks
ITCH!!
+ angioedema or anaphylaxis
60
How is urticaria treated?
1. anti histamines
| 2. corticosteroids (if severe)
61
what are the main causes of contact dermatitis?
1. ALLERGIC CONTACT DERMATITIS
allergic reaction to allergen
type IV hypersensitivity reaction
e.g. hair dyes causing scalp eczema and rash
2. IRRITANT CONTACT DERMATITIS
not an allergic reaction , but more common in atopic people
e.g. soaps, detergent, mild acids/alkalis
62
How might a contact dermatitis rash appear?
```
occurs with direct contact with the causative agent
erythema
small/ large blisters
oedema
dryness, scaling
lichenification
```
63
How is contact dermatitis diagnosed?
skin patch test
64
How is contact dermatitis treated?
1. avoid direct contact with cause!!
2. wear gloves, dry skin carefully
3. regular use of emollients
4. short term use of topical corticosteroids
65
Describe the lesions of lichen planus?
```
P - purple
P- pruritus
P- papule
P - planar
P - poly angular
```
+ Wickhams striae = white lacy markings on surface
+ nail thinning
+ Koebner phenomenon = new skin lesions appearing at site of trauma
66
Where do lichen planus lesions occur?
on flexor surfaces of wrists, forearms, ankles, genitalia
at sites of trauma (koebner phenomenon)
67
How is lichen planus managed?
topical steroids
| benztdamine mouthwash for oral lichen planus
68
Who does lichen planus affect?
common over age of 40 and women
chronic inflammatory skin condition with unknown aetiology
can be caused by gold, quinine or thiazide diuretics
69
How are common warts caused?
human papilloma virus in keratinocytes
70
How can common warts be managed?
1. topical salicylic acid
| 2. cryotherapy
71
What are molluscum contagiosum?
pox virus causing pink papule have umbilicate central punctum (no treatment needed)
72
How is impetigo caused?
CONTAGIOUS INFECTION
staph aureus and strep pyogenes
honey coloured crusts on erythematous base
73
How is impetigo managed?
oral flucloaxcillin
| only return to school/ work when no longer contagious (48 hr after treatment started or when all lesions crusted over)
74
How does rosacea present?
Erythema over nose and cheeks
Telangiectasia
No comeodones
75
How is rosacea worsened?
Alcohol
Sunlight
Steroids
76
How is rosacea treated?
1. Topical metronidazole (metrogel) or Adelaic acid
| 2. Oxytetracycline 500mg bd
77
What are the differentials for rosacea?
SLE Malar rash
Photo sensitivity
Contact dermatitis
78
Who is guttate psoriasis common in?
Common after throat infection
| So do throat swab and treat infection
79
how does angioedema present?
swelling of tongue and lips
80
how does anaphylaxis present?
bronchospasm
facial and laryngeal swelling / oedema
hypotension
can present first with urticaria and angioedema
81
What are the complications of angioedema or anaphylaxis?
asphyxia
cardiac arrest
death
82
How is anaphylaxis treated?
1. ABCDE - oxygen, maintain airway
2. adrenaline IM- 1 in 1000, 0.5ml IM
3. IV hydrocortisone 200mg
4. anti histamines - chlorphenamine 10mg
83
List the possible dermatological emergencies?
```
urticaria, angioedema and anaphylaxis
erythema nodosum
erythema multiform
stevens johnson, toxic epidermal necrosis
acute meningococcaemia
erythroderma
eczema herpeticum
necrotising fasciitis
```
84
How is erythema nodosum caused?
= hypersensitivity response to a variety of stimuli
- Group A beta haemolytic strep
- primary TB
- malignancy
- sarcoidosis
- IBD*
- chlamydia
85
Describe the rash in erythema nodosum?
discrete tender nodules for 1-2 weeks commonly on the shins
leave bruise like discolouration as they resolve
86
How is erythema multiforme caused?
herpes simplex virus **
other infections and drugs e.g. penicillin
mycoplasma pneumonia
87
Describe erythema multiform rash
hypersensitivity causing TARGET shaped rash +/- mucosal involvement
88
Describe Stevens Johnson syndrome
mucocutaneous necrosis with at least 2 mucosal sites involved +/- prodromal illness
89
Describe Steven johnson syndrome histopathology
epithelial necrosis with few inflammatory cells
90
What is toxic epidermal necrosis and its features?
usually drug induced, acute severe illness with extensive skin + mucosal necrosis + systemic upset
91
Describe the histopathology of toxic epidermal necrosis
full thickness epidermal necrosis with sub epidermal detachment
92
What are the features of acute meningococcaemia?
1. features of meningitis - headache, fever, neck stiffness
2. non blanching purpuric rash on the trunk and extremities - can be preceded by blanching maculopapular rash and rapidly progresses to haemorrhage bullae and necrosis
93
what is erythroderma?
exfoliative dermatitis involving at least 90% of the skin surface
94
How is erythroderma caused?
previous skin disease e.g. eczema, psoriasis
drugs e.g. gold, penicillin, allopurinol, sulfonylurea
withdrawal of steroids
lymphoma
95
How does erythroderma present?
skin is inflamed(red), oedematous and scaly for 90% of body
| + systemically unwell (lymphadenopathy, malaise)
96
How is erythroderma managed?
1. treat cause
2. emollients and wet wraps (maintain skin moisture)
3. topical steroids (reduce inflammation)
97
What are the complications of erythroderma?
```
secondary infection
fluid loss
electrolyte imbalance
hypothermia
high output cardiac failure
capillary leak syndrome
```
98
What is eczema herpeticum and how is it caused?
serious complication of atopic eczema caused by herpes simplex virus
99
How does eczema herpeticum present?
extensive crusted papules, blisters and erosions
| + systemically unwell e.g. fever, malaise
100
How is eczema herpeticum managed?
1. acyclovir (anti viral)
| 2. antibiotics for secondary bacterial infection
101
what are the complications of eczema herpticum?
herpes hepatitis
encephalitis
DIC
death
102
What is necrotising fasciitis?
rapidly spreading infection of the deep fascia with secondary tissue necrosis
103
How is necrotising fasciitis caused?
type 1 - mixed anaerobes
| type 2 - group A haemolytic strep e.g. strep progenies
104
What are the risk factors for necrotising fasciitis?
abdominal surgery **
diabetics
malignancy
105
how does necrotising fasciitis present?
severe pain
erythematous, blistering, necrotic skin
systemically unwell - fever and tachycardia
crepitus
106
what would x ray show on necrotising fasciitis?
soft tissue gas
107
How is necrotising facsiitis treated?
1. surgical debridement/ amputation
| 2. IV abx
108
How is Bowens disease managed?
1. fluorouracil cream 5%
| 2. cryotherapy
109
what is a keratocathoma?
solid core filled with keratin
| arise from hair follicle cells
110
Other than Breslow thickness, how are melanomas classified?
CLARK SCALE
Level 1 is also called melanoma in situ – the melanoma cells are only in the outer layer of the skin (the epidermis)
Level 2 means there are melanoma cells in the layer directly under the epidermis this is known as the papillary dermis (superficial dermis)
Level 3 means the melanoma cells are touching the next layer down known as the reticular dermis (deep dermis)
Level 4 means the melanoma has spread into the reticular dermis
Level 5 means the melanoma has grown into the layer of fat under the skin (subcutaneous fat)
111
Who is at risk of keloid scars?
dark skin
| young adults
112
where do keloid scars commonly occur?
```
sternum
shoulder
neck
face
extensor surfaces
```
113
List the available topical steroids from mild- potent?
mild : hydrocortisone 0.5-2.5%
moderate: betametasone valerate (betnovate RD) 0.025%
potent: fluticasone propionate 0.05% , Betamethasone valerate 0.1% (betnovate)
very potent: clobetasol propionate 0.05% (dermovate)
114
What are the complications of eczema?
secondary bacterial infections
eczema herpeticum
psychosocial
115
What are the side effects of isotretinoin (roacutane)?
teratogenic
depression + suicidal thoughts
dry mucous membranes
hepatitis
116
How does pemphigus vulgaris present?
younger , intra - epidermal split in skin
| vesicles and bullae + mouth ulceration (differ to bullies pemphigoid)
117
How is pemphigus vulgaris treated?
biopsy
| oral steroids and immunosuppression
118
what is the nikorsky sign?
rubbing of skin causes skin to come off
```
+ve = pemphigus vulgaris
-ve = bullous pempigoid
```
119
List the differentials for pruritus?
localised causes: psoriasis, eczema, contact dermatitis, lichen sclerosis, urticaria
systemic causes: iron deficiency anaemia, polycythaemia rubra vera, CKD, cholestasis, primary biliary cirrhosis, primary sclerosing cholangitis , pregnancy
exposure: drugs (opioids, aspirin), cold weather, allergens, insects
120
How can you treat pruritus symptomatically?
```
wet dressings
calamine lotion
menthol lotion
emollients
anti histamines
```
121
What is lichen planus?
T cell mediated autoimmune disease
122
name a tumour marker in melanoma
s-100
| TA-90
