Dermatology Flashcards
1
Q
SJS vs TEN?
A
SJS: <10% skin involvement
TEN: >30%
2
Q
Aetiology SJS/TEN?
A
secondary to drug reaction (Never Press Skin As It Can Peel) NSAIDS Phenytoin Sulphonamides Allopurinol IVIG Carbamazepine Penicillin
3
Q
S/S SJS/ten?
A
Scalded skin appearance over an extensive area
systemic upset
4
Q
Ix SJS/TEN?
A
Nikolsky’s sign positive (epidermis separates with mild lateral pressure)
5
Q
Mx SJS/TEN?
A
stop precipitating factor
ITU
IVIG
Immunosuppression (ciclosporin, cyclophosphamide) plasmapheresis
6
Q
What is erythroderma?
A
any rash involving >95% of the body
7
Q
causes of erythroderma?
A
eczema psoriasis drugs (gold) lymphoma, leukaemia idiopathic
8
Q
complications of erythroderma
A
dehydration
high output cardiac failure
infection
9
Q
what is seborrhoeic dermatitis?
A
chronic dermatitis caused by an inflammatory reaction related to a proliferation of a normal skin fungus (malassezia furfur)
10
Q
who does seborrhoeaic dermatitis commonly affect?
A
immunosuppression (HIV)
Neurological (PD, Down’s, epilepsy)
Alcoholic pancreatitis
11
Q
S/S of seborrhoeic dermatitis?
A
Eczematous lesions on sebum rich areas (dandruff, periorbital, auricular and nasolabial folds)
may present with otitis externa, blepharitis
12
Q
Mx seborrhoeic dermatitis?
A
Scalp disease:
1st line: zinc pyrithione (‘head and shoulders’) and tar (‘neutrogena T/Gel’)
2nd line: ketoconazole
alternatives: selenium sulphide, topical corticosteroid
Face and body disease: topical antifungals (ketoconazole) topical steroids (short periods)
13
Q
What is impetigo?
A
common skin infection caused by staph aureus, streptococcus pneumonia
14
Q
S/S impetigo?
A
golden yellow crusted appearance
15
Q
Management of impetigo?
A
hygiene meaures
Localised non-bulbous: topical H2O2 cream (peroxide), topical fusidic acid antibiotic
widespread non bullous; oral flucloxacillin OR topical fusidic acid 2% antibiotic
bullous systemically unwell: oral flucloxacillin
School exclusion until lesions crusted over OR 48 hour after Abx started
16
Q
which bacterium causes acne vulgarisms?
A
increased sebum and blocked glands
propionibacterium acnes
20% of adolescents have moderate to severe acne
17
Q
what are the levels of acne?
A
comedones (follicles impacted and distended by incompletely desquamated keratinocytes and sebum) - open or closed
papules and pustles
nodulocystic and scarring
18
Q
S.S of acne vulgaris?
A
greasy face
comedones, papules, pustules, nodules
psychological impact, low self esteem
19
Q
when do you do a dermatologist referral for acne?
A
nodulocystic acne/scarring severe form (acne conglobata, acne fulminano) severe psychological distress diagnostic uncertainty failing to respond to medications
20
Q
Acne management?
A
Conservative:
- avoid over cleaning skin (2x day with gentle soap_
- use emollients and cleansers (non-comdeogenic)
- face : avoid picking and squeezing (scars)
meds:
Mild: 1st: topical retinoid and/or benzoyl peroxide +/-topical Abx /2nd line: azelaic acid
moderate: oral Abx (max 3m) + BPO + retinoid OR cocp + BPO/retinoid
severe: dermatologist referral - oral isotretinoin, once cleared maintain with topical retinoids or azelaic acid
Support; NHS choices leaflet, british association of dermatologists
21
Q
Which Abx are preferred for acne?
A
topical: clindamycin 1%
oral: 1st line tetracyclines (lymecycline, doxycycline), 2nd line macrolides (erythromycin)
22
Q
What are the S/S of acne rosacea?
A
1: flushing
2: asymmetrical rash of nose, cheeks, forehead and telangiectasia
3: persistent pustulopapular erythema (rhinopehyma, ocular involvement- blepharitis, photosensitivity)
commonly worsens with alcohol
23
Q
Acne vulgaris vs acne rosacea?
A
vulgaris = young, comedones rosacea = middle-aged, flushing, symmetry
24
Q
Management of acne rosacea?
A
mild/moderate: topical metronidazole
severe: oral tetracycline (oxytetracycline)
flushing, limited telangiectasia: topical brimonidine gel
adjuncts: high factor sunscreen, camouflage creams, laser therapy (telangiectasia)
25
What is hidradenitis suppurativa?
chronic inflammatory occlusion of folliculopilosebaceous units that obstructs the porcine glands and prevents keratinocytes from properly shedding from the follicular epithelium
26
RF for hidradenitis suppurativa?
FHx
obesity, DM, PCOS
Smoking
Mechanical skin stretching
27
S/s hidradenitis suppurativa?
recurrent build in intertriginous areas (axilla, neck, thights, inguinal)
coalesce of nodules can result in plaques, sinus tracts and rope like scarring
28
Management of hidradenitis suppurativa?
conservative: good hygiene and loose fitting clothing
smoking cessation
WL
medical:
acute - steroids,flucloxacillin +/- surgical incision and drainage
chronic - clindamycin (topical), lymecycline/clindamycin/rifampicin PO
29
What is pityriasis versicolor?
caused by malassezia furfur
| common fungal infection that causes small patches of skin to become scaly and discoloured
30
What are the S/S of pityriasis versicolor?
trunk affected - hypopigmneted patches and scale, mild pruritic, follows a suntan
31
triggers for pityriasis versicolor?
immunosuppression, malnutrition, Cushing's
32
Mx pityriasis versicolor?
topical ketoconazole
33
pityriasis versicolor vs vitiligo?
vitiligo affects peripheries and is much more confluent
34
what are the S/S of vitiligo?
well demarcated, depigmented skin patches
35
Vitiligo associations?
T1DM,Addisons, autoimmune thyroid, pernicious anaemia, alopecia areata
36
Mx vitiligo?
sunblock
camouflage makeup
topical corticosteroids (reverse changes if applied early)
37
what causes pityriasis rosea?
HHV-7
38
S/S of pityriasis rosea?
1: recent viral infection -> herald patch (usually on trunk)
2: erythematous oval scaly patches (running parallel to the line of Langer 'fir tree appearance')
Mx: self limiting (6-12w)
39
What are the types of psoriasis?
plaque
guttte
pustular
flexural
40
what are the features plaque psoriasis?
most common; well demarcated red, scaly patches affecting extensors
41
what are the features of guttate psoriasis?
streptococcal infection; multiple transient, red, teardrop lesions
no mx required
42
what are the features of pustular psoriasis?
palms and soles of feet
43
what are the features of flexural psoriasis?
skin is smooth in contrast to plaque psoriasis
44
Exacerbating factors for psoriasis?
trauma
ETOH
drugs (beta blockers, lithium, antimalarials, NSAIDs, ACEi, infliximab)
withdrawal of systemic steroids
infection (strep infection may trigger guttate psoriasis subtype only)
45
Management of chronic psoriasis plaque?
corticosteroids:
potent - use max 8w at a time
very potent - use max 4w at a time
4w breaks between courses of topical corticosteroids
SE: skin atrophy, striae, rebound symptoms
vitamin D analogue info
reduced scaling and thickness but no effect erythema
can be used long term
avoid in pregnancy
46
Management of psoriasis in primary care?
```
1st line (4w trial): OM corticosteroid (potent) and ON vitamin D analogue
2nd line (after 8 w): OM corticosteroid (potent) and BD vitamin D analogue
3rd line: BD corticosteroid (4w potent) or coal tar (OD or BD)
```
Adjunct: emollients (reduce scale loss, reduce pruritic)
Alternative: short acting dithranol (wash off after 30m)
47
Management of psoriasis in secondary care?
phototherapy (P-UVB, 3x/Week) or photochemotherapy (P-UVA + psoralen)
Systemic medications: 1st methotrexate; other: ciclosporin, retinoids, infliximab, etanercept, adalimumab
48
What is eczema?
chronic, relapsing, inflammatory skin condition characterised by an itchy red rash, commonly on FLEXURES
49
Eczema triggers?
irritants, contact allergens, extremes of temperature (worse in winter), abrasive fabrics, sweating
50
Signs & symptoms of eczema
infant: face and trunk
older child: extensors of limbs
young adult: localises to the flexures
51
Investigations eczema?
consider food allergies - blood or skin prick testing
| consider contact dermatitis - patch testing
52
management of eczema?
flared - treat ASAP and for 24h post symptoms
53
What is the steroid ladder?
```
Help every busy dermatologist
Hydrocortisone
Euvomate (clobetason)
Betnovate (betamethasone)
(elocon - mometasone)
Dermovate (clobetasol)
```
54
How is mild eczema managed?
emollients
| mild potency topical steroids (hydrocortisone)
55
How is moderate eczema managed?
emollients
moderate potency topical corticosteroids
topical calcineurin inhibitors
bandages
56
How is severe eczema managed?
```
emollients
potent topical corticosteroids
systemic therapy
phototherapy
topical calcineurin inhibitors
bandages
```
antihistamines (non sedating vs sedating at night)
57
How is infected eczema managed?
```
skin swab and culture
oral flucloxacillin (erythromycin if pen allergic)
```
58
how is eczema herpeticum managed?
oral acyclovir
if around eyes same day referral to ophthal
health education (emergency = rapidly worsening eczema, clustered blisters, punched out erosions)
N.b. eczema herpeticum can look similar to impetigo so treat for both empirically with oral/IV Abx and oral/IV acyclovir
59
what are the directions for applying emollient?
apply to whole body and wait 30 mins before applying steroid creams
apply with Finger tip units (FTU)
60
What is 1 FTU?
Palm of hand
elbows
knees
61
give and example of a mild and moderate/severe calcineurin inhibitors?
mild/mod: pimecrolimus
| mod/severe: tacrolimus
62
What is tinea?
fungal infection where dermatophyte fungi incase dead keratinous structure (trichophytum rubrum)
63
S/S of tinea?
ringed appearance +/- keri on (severe inflamed ringworm patch), red or silver rash
Tinea capitis - scalp
Tinea pedis - feet
64
Mx tinea?
Tinea capitis:
oral anti fungal (e.g. griseofulvin or terbinafine)
Other tinea:
mild: topical antifungals e.g. topical terbinafine, clotrimazole, miconazole
moderate: hydrocortisone 1% cream
severe: oral antifungals (1st line oral terbinafine, 2nd line: oral itraconazole
65
What advice should be given for managing tinea?
```
very contagious
wear loose fitting cotton clothing
dry throroughly after washing
do not share towels
no need for school exclusion
wash affected areas of skin daily
avoid scratching
wash clothes and bed linen frequently
```
66
what is shingles?
Herpes zoster infection - reactivation of VZV
67
RFs for shingles?
Increasing age
| Immunosuppression (HIV 15x more common, steroids, chemotherapy)
68
S/S shingles?
```
prodromal period (burning over affected dermatome for 2-3 days+/- fever, headache, lethargy
rash (erythematous, macular rash over the affected dermatome - vesicular)
```
69
Management of shingles?
infectious until vesicles have crusted over
analgesia (paracetamol and NSAIDs), neuropathic agents, oral corticosteroids
Antivirals (PO acyclovir) (<72h, >50yo)
70
Complications of shingles?
- post-herpetic neuralgia (5-30% of patients depending on age)
- herpes zoster ophthalmicus
- herpes zoster optics (Ramsay-hunt syndrome)
71
what is actinic keratosis?
pre-malignant skin condition for SCC
72
S/S actinic keratosis?
small, crusty or scaly, lesions, sun-exposed areas
73
Management actinic keratosis?
GP if simple, urgent 2WW dermatology if immunosuppressed:
Fluorouracil cream (2-3w) +/- topical hydrocortisone
Topical diclofenac (mild AKs)
Topical imiquimod
Cryotherapy
Curettage and cautery
74
what is keratocanthoma?
pre-malignant skin condition for SCC
| has rapid growth phase
75
S/S keratocanthoma?
small, dome shaped papule - crater filled with keratin
76
Mx keratocanthoma?
excision
77
Aetiology of fungal nail infections?
dermatophytes
78
Ix fungal nail infection?
nail clipping MC&S
79
Mx of fungal nail?
patient choice (must be confirmed by MCS before treatment)
- nil: asymptomatic and patient not bothered by appearance
- dermatophyte infection: 1st: PO terbinafine, 2nd PO itraconazole (finger 6w-3m, toe 3m-6m)
- candida infection: mild = topical anti fungal (amorolfine), severe = oral itraconazole (12w)
80
what must be checked before prescribing terbinafine/itraconazole?
LFTs
81
What are the S/S of lichen plants?
```
Ps
Purple
pruritic
papular
polygonal rash on flexors
```
Wickham's striae (thin white lines in mouth)
82
Causes of lichen planus?
gold
quinine
thiazides
83
Management of lichen planus?
body -> topical steroids (clobetasone butyrate)
oral -> benzydamine mouthwash
xtensive lichen planus may require oral steroids or immunosuppression
84
S/S lichen sclerosus?
itchy white spots typically seen on the vulva of elderly women
85
mx lichen sclerosus?
1st (3m): clobetasol propinate
| 2nd: tacrolimus + biopsy
86
what is the cause of cellulitis?
streptococcus pyogenes OR staphylococcus aureus
87
S/S of cellulitis?
poorly demarcated deep skin infection
88
what is the Eron classification for cellulitis?
I: no signs of systemic toxicity, person has no uncontrolled co-morbidities
II: systemically unwell or systemically well but with a co-morbidity
III: significant systemic upset such as acute confusion, tachycardia, tachypnoea, hypotension or unstable co-morbidities
IV: sepsis, necrotising fasciitis
89
Management of cellulitis?
mild/moderate: flucloxicillin (alt: clarithromycin, erythromycin, doxycycline)
severe: co-amoxiclav, cefuroxime, clindamycin, ceftriaxone
90
What is the cause of erysipelas?
streptococcus pyogenes (group A haemolytic strep)
91
S/S erysipelas?
well-demarcated superficial skin infection
92
Mx erysipelas?
flucloxacillin
93
Cause of erythrasma?
corynebacterium minutissimum
94
S/S erythrasma?
asymptomatic flat scaly pink/brown rash in axilla/skin crease
95
Ix erythrasma?
Woods slit lamp, coral red fluorescence
96
Mx erythrasma?
topical miconazole (local) or PO erythromycin
97
What are the common shin conditions?
erythema nodosum
pretibial myoxedema
pyoderma gangrenosum
necrobiosis lipodica diabeticorum
98
Causes of erythema nodosum ?
```
streptococcal infections, TB, brucellosis
sarcoidosis
IBD
drugs (penicillins, sulphonamides, COCP)
malignancy
```
99
S/S erythema nodosum?
symmetrical erythematous tender nodules which heal without scaring
100
S/S pretibial myxoedema?
symmetrical erythematous lesions seen in Graves
| shiny orange peel skin
101
Causes of pyoderma gangrenosum?
idiopathic (50%)
IBD
Connective tissue disorders and myeloproliferative disorders
102
S/S pyoderma gangrenosum?
1st - small red papule
| 2nd - later deep red, necrotic ulcers with a violaceous border
103
Mx pyoderma gangrenosum?
oral steroids
104
What necrobiosis lipoidica diabeticorum associated with?
telangiectasia, diabetes
105
S/S necrobiosis lipoidica diabeticorum?
shiny, painless areas of yellow/red skin
| seen on diabetics
106
What is bullous pemphigoid ?
Abs against BM (dermoepidermal junction)
107
S/S bullous pemphigoid?
itchy tense blisters, no oral involvement
108
Mx bullous pemphigoid?
oral corticosteroids
109
what is pemphigus vulgaris?
Abs against desmosomes
110
S/S pemphigus vulgaris?
flaccid blisters
| oral involvement
111
what areas does erythema nodosum affect?
legs, knees, arms
112
causes erythema nodosum?
```
SORE SHINS
Streptococci, mycoplasma, EBV
OCP
Rickettsia
Eponymous (Behcets)
```
```
Sulphonamides, penicillin
Hansens (leprosy)
IBD/idiopathic
Non Hodgkin's
Sarcoidosis/TB
```
113
What causes erythema multiforme?
```
a hypersensitivity reaction
Infection (90%): HSV> mycoplasma
Drugs (<10%): barbiturates, NSAIDs, penicillin, sulphonamides, sulphonylurea, nitrofurantoin
SJS/TEN
SLE
Sarcoid
malignancy
```
114
what causes erythema ab igne?
chronic exposure to heat (hot water bottle, open fire)
115
what does erythema ab igne increase likelihood of?
SCC
116
what causes erythema chronicum migrans?
borrelia burgdorferi (spirochete, Ixodes tick)
117
S/S erythema chronicum migrans?
localised (rash, flu-illness), early disseminated (arthritis, carditis), late disseminated (chronic disorders)
118
what causes erythema marginatum?
rheumatic fever (GAS)
119
S/S erythema marginatum?
```
CASES FRAPP
carditis
arthritis
syndenhams chorea
erythema marginatum
SC nodules;
```
```
fever
raised ESR
arthralgia
prolonged PR
previous rheumatic fever
```
120
what causes migratory necrolytic erythema?
glucagonoma
121
What is a pyogenic granuloma?
a reactive proliferation of capillary blood vessels - usually follow trauma
self-limiting
122
what is a sebaceous cyst?
epithelial lined cavity containing keratin
| - encompasses epidermoid and pilar cysts
123
where are sebaceous cysts most common?
```
scalp
ear
face
back
upper arm
```
124
what are the most common penile skin disorders?
lichen sclerosis
zoon's balanitis
circinate balanitis
erythroplasia of queyrat
125
what is lichen sclerosis of penis?
tight white ring around tip of foreskin + phimosis
126
what is zoons balanitis?
unknown origin; secondary to lichen sclerosis/EOQ
127
what are the S/s of zoons balanitis?
orange red lesions + pin point red spots
128
what is circinate balanitis?
balanitis in reactive arthritis
129
what are the S/S of circinate balanitis?
well demarcated erythematous plaque with a ragged white border
130
What is erythroplasia of Queyrat?
in situ SCC
| single or multiple plaques with a red velvety appearance
131
what is the management of athletes foot?
1st: topical antifungals (ie clotrimaole, imidazole)
| 2nd oral antifungals ie PO terbinafine
132
What is the inheritance pattern for hereditary haemorrhagic telangiectasia/Osler-Weber-Rendu?
AD
133
What are the S/S HHT?
4 diagnostic criteria (>=3 for diagnosis)
1. epistaxis
2. telangiectasia (lips, oral cavity, finers, nose)
3. visceral lesions (GI +/- anaemia, AVM pulmonary/hepatic/spinal/cerebral)
4. FHx (1st degree)
134
What does granuloma annulare looks like?
papular lesions
| slightly hyperpigmented and depressed centrally
135
Where does granuloma annulare occur?
dorsal surfaces of the hands/feet
| extensor aspects of the arms and legs
136
what causes scabies?
mite sarcoptes scabiei
137
where does the mite lay its eggs in scabies?
stratum corneum
138
what causes the intense pruritis associated with scabies?
delayed type IV hypersensitivity reaction to mites/eggs which occurs at about 30 d
139
What are the S/S of scabies?
widespread pruritis
linear burrows on the side of fingers, interdigital webs and flexor aspects of the wrists
pruritic can persist for up to 6 weeks post treatment
140
Mx scabies?
permethrin 5% (2x OW full body treatments; wash off after 8-12 hours) + treat all household/close contacts
2nd line: malathion, wash off after 24 h
141
what is the Mx for head lice?
malathion, wash off after 24 h
142
What is a dermatofibroma?
benign overgrowth of dermal fibroblasts
| often caused by previous trauma
143
S/S dermatofibroma?
F>M
firm
woody
solitary firm papule or nodule, typically on a limb
typically around 5-10mm in size
overlying skin dimples on pinching the lesion
144
Mx dermatofibroma?
nil
145
what is a neurofibroma?
benign overgrowth of nerves?
146
Aetiology of seborrhoeic keratosis?
hyperkeratosis (thickened stratum corneum)
acanthosis (thickened stratum spinosum)
hyperplasia of basal cells
147
S/S seb K?
greasy
stuck on
cauliflower like growth
148
What is sudden onset multiple seb k called?
Leser Trelat sign (?underlying malignancy)
149
what may cause an intradermal lump?
(within dermis)
dermatofibroma
epidermal cyst
intradermal naevus
150
what may cause subcutaneous lump ?
```
(below the dermis)
neurofibroma
panniculitis
lipoma
ganglion
lymph nodes
```
151
Features of a pyogenic granuloma?
most common sites are head/neck, upper trunk and hands. Lesions in the oral mucosa are common in pregnancy
initially small red/brown spot
rapidly progress within days to weeks forming raised, red/brown lesions which are often spherical in shape
the lesions may bleed profusely or ulcerate
152
Management of pyogenic granuloma?
lesions associated with pregnancy often resolve spontaneously post-partum
other lesions usually persist. Removal methods include curettage and cauterisation, cryotherapy, excision
153
What are the side effects of roaccutane?
```
dryness, teratogenic -must be on 2 forms of contraception
raised TGs
hair thinning
intracranial HTN
photosensitivity
low mood/suicidal ideation
```
154
what is the commonest skin disorder in pregnancy?
atopic eruption of pregnancy
155
What is polymorphic eruption of pregnancy?
pruritic condition associated with last trimester
lesions often first appear in abdominal striae
management depends on severity: emollients, mild potency topical steroids and oral steroids may be used
156
what is pemphigoid gestationis?
pruritic blistering lesions
often develop in peri-umbilical region, later spreading to the trunk, back, buttocks and arms
usually presents 2nd or 3rd trimester and is rarely seen in the first pregnancy
oral corticosteroids are usually required
157
what are the features of erythema multiforme?
target lesions
initially seen on the back of the hands / feet before spreading to the torso
upper limbs are more commonly affected than the lower limbs
pruritus is occasionally seen and is usually mild
158
what is erythema multiforme major?
severe form of erythema multiforme
| severe form, erythema multiforme major is associated with mucosal involvement ie mouth
159
What is alopecia areata?
autoimmune condition causing localised, well demarcated patches of hair loss. At the edge of the hair loss, there may be small, broken 'exclamation mark' hairs
160
what is the prognosis of alopecia areata?
Hair will regrow in 50% of patients by 1 year, and in 80-90% eventually
161
Treatment options for alopecia areata
```
topical or intralesional corticosteroids
topical minoxidil
phototherapy
dithranol
contact immunotherapy
wigs
```
162
causes of erythema nodosum?
```
NODOSUM
no - idiopathic
d - drugs
o - oral contraceptive/pregnancy
s - sarcoid/tb
u - ulcerative colitis/crohn's/behcets
m - microbiology (strep,mycoplasma, EBV)
```
163
Causes of acanthosis nigricans?
```
type 2 diabetes mellitus
gastrointestinal cancer
obesity
polycystic ovarian syndrome
acromegaly
Cushing's disease
hypothyroidism
familial
Prader-Willi syndrome
drugs
- combined oral contraceptive pill
- nicotinic acid
```
164
What are the features of BCC
The most common type is nodular BCC
sun-exposed sites, especially the head and neck account for the majority of lesions
initially a pearly, flesh-coloured papule with telangiectasia
may later ulcerate leaving a central 'crater'
165
Mx BCC?
```
surgical removal
curettage
cryotherapy
topical cream: imiquimod, fluorouracil
radiotherapy
```
166
Where does acral lentiginous melanoma occur?
occurs in areas not exposed to the sun such as soles of feet and palms
Nails, palms or soles, African Americans or Asians
167
Features of melanoma?
size > 5mm, irregular border, poorly defined borders, irregular pigment network and background erythema
168
What are the types of melanoma?
superficial spreading
nodular
lentigo maligna
acral lentiginous melanoma
169
features of superficial spreading melanoma?
70% cases
Arms, legs, back and chest, young people
A growing moles with diagnostic features
170
features of nodular melanoma?
Sun exposed skin, middle-aged people
Red or black lump or lump which bleeds or oozes
most aggressive
171
features of lentigo maligna?
Chronically sun-exposed skin, older people
| A growing mole with diagnostic
172
what are the main diagnostic features of melanoma?
Change in size
Change in shape
Change in colour
```
Secondary features (minor criteria)
Diameter >= 7mm
Inflammation
Oozing or bleeding
Altered sensation
```
173
Mx melanoma?
Suspicious lesions should undergo excision biopsy. The lesion should be removed in completely as incision biopsy can make subsequent histopathological assessment difficult.
Once the diagnosis is confirmed the pathology report should be reviewed to determine whether further re-excision of margins is required
174
What is melanoma excision of margins related to?
Breslow thickness
Lesions 0-1mm thick 1cm
Lesions 1-2mm thick 1- 2cm (Depending upon site and pathological features)
Lesions 2-4mm thick 2-3 cm (Depending upon site and pathological features)
Lesions >4 mm thick 3cm
175
What is Koebners phenomenon?
```
where lesions are seen at the site of injuries.
It is seen in:
psoriasis
vitiligo
warts
lichen planus
lichen sclerosus
molluscum contagiosum
```
