Medicine - Dermatology Flashcards
How can you differentiate between SJS and TEN?
SJS = up to 10% skin involvement TEN (Toxic epidermal necrolysis) = \>30% skin involvement
What is Nikolsky’s sign?
Epidermis separates with mild lateral pressure - secondary to adverse drug reaction
How should SJS or TEN be managed?
Stop the cause
Transfer to ITU
IV Ig
Immunosuppression (eg ciclosporin and cyclophosphamide)
Which drugs are most likely to cause SJS?
Never Press Skin As It Can Peel
NSAIDs
Phenytoin
Sulphonamides
Allopurinol
IV Ig
Carbemazapine
Penicillins
What is erythroderma?
Any rash involving >95% of the body
Recall 3 possible complications of erythroderma
Dehydration
High output heart failure
Infection
What is the cause of adult seborrhoeic dermatitis?
Fungus called malassezia furfur
Humidity & sweating linked
What 2 skin conditions can be caused by malassezia furfur?
Seborrhoeic dermatitis (pic below)
Pityriasis versicolor
What are the 1st and 2nd line options for treating scalp seborrhoeic dermatitis?
1st line = zinc pyrithione (‘head and shoulders’)
2nd line = ketoconazole
Zinc increase copper levels, damaging sulphur clusters needed for fungi
Which pathogen is the most common cause of impetigo?
Staphylococcus aureus
What are the 3 classes of impetigo and their respective management?
Localised, non-bullous: topical H2O2 1% cream / topical fusidic acid
Widespread, non-bullous: oral flucloxacillin or topical fusidic acid
Widespread, bullous: oral flucloxacillin
How long should children with impetigo be excluded from school?
Until lesions crusted over or 48 hours after antibiotics started
What are the lay terms for open and closed comedones?
Open = blackheads Closed = whiteheads
Recall some conservative management options for acne
Avoid over-cleaning face - bd with gentle soap is okay
Make up - use emollients and cleansers, non-comedonegenic preparations
Avoid picking and squeezing
How long should each acne medication be tried for to give it chance to work?
8 weeks
Recall the stepwise medical management of acne
Mild acne:
1st line: topical retinoid and or benzyl peroxide +/- topical clindamycin (which is never prescribed alone)
2nd line: azelaic acid 20%
Moderate (if not responding to topicals) acne:
- oral tetracycline + BPO/retinoid
OR
- oral COCP + BPO/retinoid
Dermatologist referral:
- Oral isotretinoin (roaccutane)
Once acne has cleared, how should this be maintained?
Topical retonoids and azelaic acid
What is Roaccutane?
Synthetic vitamin A
What pregnancy prevention plan should be in place for Roaccutane?
2 forms of contraception as it is very teratogenic
Recall some side effects of Roaccutane
Dry skin
Raised triglycerides
Hair-thinning
Intracranial HTN
Photosensitivity
Low mood
Suicidal ideation
DR HIPLS
What accumulated dose should you aim for with Roaccutane?
Body weight in kg x 100 mg
What is the progression of symptoms of rosacea?
1st = flushing 2nd = symmetrical facial rash with telangiectasia 3rd = persistent pustulopapular erythema
How should rosacea be managed?
Mild-moderate = topical metronidazole Severe = oral tetracycline
Metronidazole- inhibits protein synthesis stopping growth
What is the aetiology of hidradenitis supparativa?
Chronic inflammatory occlusion of folliculopilosebaceous units that obstructs the apocrine glands and prevents keratinocytes from properly shedding the follicular epithelium
In lay terms, what is hidradenitis supparativa?
Abscesses that form near hair follicles in places where we tend to sweat more
What are the 2 biggest risk factors for hidradenitis supparativa?
Smoking and obesity
Rarely, what inflammatory disease is associated with
hidradenitis supparativa?
Crohn’s
How can hidradenitis supparativa be managed?
Conservative: weight loss, stop smoking, hygeine
Acutely: steroids PO, flucloxacillin, I&D
Chronically: topical clindamycin
What pathogen causes pityriasis versicolor?
Malassezia furfur
How does pityriasis versicolor appear?
Hypopigmented patches on trunk
Mild pruritis
How is pityriasis versicolor managed?
Topical ketoconazole
How does vitiligo appear?
Well demarctaed, depigmented skin patches usually affecting the peripheries
Recall some associations of vitiligo (don’t need to know in detail)
T1DM
Addison’s
Autoimmune thyroid
Pernicious anaemia
Alopecia areata
How can vitiligo be managed?
Sunblock Topical corticosteroids (reverses changes if applied early)
What pathogen causes pityriasis rosea?
HHV-7
Describe the presentation of pityriasis rosea
Recent viral infection –> herald patch
Then erythematous, oval scaly patches
How should pityriasis rosea be managed?
It is self-limiting (6-12w) so no need
Broadly describe the 4 types of psoriasis
Plaque - most common, is well-demarcated red and scaly - affects scalp, back, extensors
Guttate - following a strep infection, “tear drop” lesions
Pustular - affects palms and soles
Flexural - skin is smooth
Recall some factors that exacerbate psoriasis
Trauma
EtOH
Certain drugs
Which drugs can exacerbate psoriasis?
INFLAME
Infliximab
NSAIDs
For HTN (beta blockers)
Lithium
ACE inhibitors
Malarial drugs
EtOH
How should chronic plaque psoriasis be managed in primary care? (give 1st, 2nd and 3rd line)
1st line: 4w trial of OM potent corticosteroid and ON (once daily) vitamin D analogue
2nd line: after 8w (so 4w break): OM potent corticosteroid and BD (twice daily) vitamin D analogue
3rd line: 4w trial of BD potent corticosteroid OR coal tar
Use emollients as an adjunct
What is the maximum duration of use of topical potent and very potent steroids before a break is needed?
Potent = 8w
Very potent = 4w
How can chronic plaque psoriasis be managed in secondary care?
Phototherapy/photochemotherapy Systemic immunosuppression (eg infliximab, etanercept, ustekinumab)
Describe the distribution of eczema in infants vs children vs young adults
Infants: face and trunk
Child: extensors
Young adult: flexures
Describe the different severities of eczema in terms of physical symptoms
Mild: infrequent itching, some areas of dry skin and a little redness
Moderate: frequent itching, lots of redness and some excoriation
Severe: widespread dryness, incessant itching, redness, excoriation, thickening, cracking, alteration of pigmentation
How should eczema be investigated?
Consider food allergy and contact dermatitis
Skin prick tests
Patch tests
How long should flares of eczema be treated for?
Treat ASAP and for 48 hours after resolution of symptoms
Recall the management of mild, moderate and severe eczema
Mild: emollients, mild potency topical corticosteroids
Moderate: emollients, moderate potency topical corticosteroids, topical calcineurin inhibitors (tacrolimus) and bandages
Severe: emollients, potent topical corticosteroids, topical calcineurin inhibitors, bandages and phototherapy
How should infected eczema (not herpeticum) be managed?
Skin swab and culture
Flucloxacillin PO
How should eczema herpeticum be managed?
Oral aciclovir
If around eyes, same day referral to ophthalmologist
Looks similar to impetigo so ALSO treat for that with oral aciclovir
How should topical emollients and steroids be applied
Emollients applied liberally
Wait 30 mins
then apply steroids
Recall 2 examples of topical calcineurin inhibitors that can be used to manage eczema
Mild-moderate - pimecrolimus
Moderate - severe - tacrolimus
Recall some points for PACES counselling for eczema
Explain diagosis (dry, itchy skin)
Explain epidemiology (very common, many grow out of it)
Explain management
Encourage frequent, liberal use of emollients and use of emollients as a soap substitute
Advise avoidance of triggers
Avoid scratching if poss (eg mittens for infants)
Safety ned about signs of infection
Info: itchysneezywheezy.co.uk shows how to apply emollients
What type of pathogen causes tinea?
Dermatophyte fungi
What pathogen causes tinea?
Trichophytum rubrum
How should scabies be managed?
Permethrin - full body treatment that you wash off after 8-12 hours - treat all household/close contacts
How should headlice be managed?
Malathion
How should tinea be managed?
Mild –> topical antifungals (terbinafine)
Mod–> hydrocortisone 1%
Severe–> oral antifungals (eg terbinafine)
If tinea capitis –> oral antifungal
How long should children with tinea be excluded from school?
No need
Recall 2 risk factors for shingles
Increasing age
Immunosuppression
Describe the symptoms of shingles
Prodromal burning pain over the affected dermatome for 2-3 days +/- fever, headache, lethargy
Rash begins erythematous, macular –> vesicular
For how long is shingles infectious?
Until vesicles have crusted over (about 5-7 days)
How should shingles be managed?
PO aciclovir if <72 hours from symptom onset and >50y/in lots of pain/ immunocompromised
Analgesia: paracetamol/ NSAIDs –>amitriptyline
Emergency referral if serious complications suspected
Recall 3 possible complications of shingles
Post-herpetic neuralgia
Herpes zoster ophthalmicus (affects ocular division of CNV)
Herpes zoster oticus (Ramsay Hunt syndrome)
What are the 2 pre-malignant conditions for squamous cell carcinoma known as?
Actinic keratoses and keratocanthomas
Where do actinic keratoses appear?
sun-exposed areas
How can actinic keratoses be managed medically?
Fluorouracil + topical hydrocortisone
Topical diclofenac/imiquimod
What are some surgical options for managing actinic keratoses?
Cryotherapy
Curettage and cautery
What is a keratocanthoma?
Pre-malignant skin condition (for SCC) with rapid growth (around 1 week)
How should keratocanthomas be managed?
Excision
What is the causative organism in fungal nail infections 90% of the time?
Trichophytum rubrum (dermatophyte)
How can fungal nail infections be investigated?
Nail clipping MC&S
How should fungal nail infections be managed?
Must first confirm infection by MC&S in order to commence treatment
- Can do nothing (if pt not bothered)
- Can do PO terbinafine (2nd line itraconazole)
- finger = 6w-3m
- toe = 3-6m
- If candida infection –> topical antifungals
How does lichen planus appear?
Rash is:
Purple
Pruritic
Papular
Polyglonal
Also can get thin, white lines in the mouth
Where does lichen planus tend to affect?
Flexor surfaces
Recall some causes of lichen planus
Gold
Thiazides
Quinine
How should lichen planus be managed?
Topical steroids
How does lichen sclerosus appear?
Itchy white spots typically on the vulva of elderly womenn
How should lichen sclerosus be managed?
1st: clobetasol proprionate ointment
2nd: tacrolimus and biopsy
Which 2 pathogens are most likely to cause cellulitis?
Strep pyogenes
Staph aureus
What classification system is used for cellulitis?
Eron classification
How should cellulitis be managed?
Mild/mod: flucloxacillin
Severe: co-amox
Describe the 4 severities of cellulitis under the Eron classification
I - no signs of systemic toxicity, person has no uncontrolled comorbidities
II - systemically unwell OR systemically well with an uncontrolled comorbidity
III - significant systemic upset such as acute confusion, tachycardia/tachypnoea, hypotension, unstable comorbidity
IV - sepsis/ necrotising fasciitis
What is the cause of erysipelas?
Strep pyogenes
How should erysipelas be managed?
PO flucloxacillin
What is the cause of erythrasma?
corynebacterium minitissimu
How can erythrasma be investigated?
Wood’s slit lamp –> coral-red fluorescence
How should erythrasma be managed
Topical miconazole
Recall some causes of pyoderma gangrenosum
IBD
Connective tissue disorders
Myeloproliferative disorders
Describe the classical natural history of pyoderma gangrenosum
Small red papule –> later deep, red, necrotic ulcers with a violaceous border
How should pyoderma gangrenosum be managed?
PO steroids
In what patient population is necrobiosus lipoidica diabeticorum seen and how does it appear?
Diabetics
Shiny, painless area of yellow/red skin on shins
What are antibodies directed against in bullous pemphigoid?
Basement membrane (dermo-epidermal junction)
How can bullous pemphigoid be managed?
Oral corticosteroids
How can bullous pemphigoid and pemphigus vulgaris be differentiated?
Bullous pemphigoid = tense blisters with no oral involvement
Pemphigus vulgaris = flaccid blisters with oral involvement
What are antibodies directed against in pemphigus vulgaris?
Desmosomes
What is this?
(Source: Derm Net NZ)
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Guttate psoriasis
What is this?
(source: Derm Net NZ)
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Pityriasis versicolor
What is this?
(source: Derm net NZ)
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Impetigo
What is this?
(source NHS)
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Hidradenitis supparativa
What is this?
(source: Derm Net NZ)
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Vitiligo
What is this?
(source: Derm Net NZ)
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Pityriasis rosea
What is this?
(source: NHS)
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Plaque psoriasis
What is this?
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Guttate psoriasis
What is this?
(Source: Derm Net NZ)
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Pustular psoriasis
What is this?
(Source: Derm Net NZ)
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Flexural psoriasis
What is this?
(Source: Derm Net NZ)
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Tinea corporis
What is this?
(Source: Derm Net NZ)
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Scabies
What is this?
(Source: Derm Net NZ)
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Actinic keratosis
What is this?
(Source: Derm Net NZ)
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Keratocanthoma
What is this?
(Source: Derm Net NZ)
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Lichen planus
What is this?
(Source: Derm Net NZ)
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Erysipelas
What is this?
(Source: Derm Net NZ)
Erysipelas
What is the recommended margin for excision of a malignant melanoma?
When the breslow thickness is known = 2mm
Recall 3 causes of Koebner’s phenomena
Vitiligo
Psoriasis
Lichen planus
Which type of skin lesion commonly appears in response to traume eg an insect bite?
Dermatofibroma
What type of infection is:
1. Guttate psoriasis
2. Pitryasis rosea
proceeded form
- bacterial
- viral
What is wickhams striae?
rash often polygonal in shape, with a ‘white-lines’ pattern on the surface
a sign of lichen planus
Main signs of lichen planus
planus: purple, pruritic, papular, polygonal rash on flexor surfaces. Wickham’s striae over surface. Oral involvement common
What formula is required to calculate the volume of IV fluid required for resus over the first 24 hrs post burn
parkland formula
How is hyperhidrosis managed?
topical aluminium chloride (roll on) at nighttime - SE skin irritation
Botulinum for axillary
endoscopic transthoracic sympathectomy - compensatory sweating
what is this
bullous pemphigoid
ig3 and c3 at dermoepidermal junction
oral corticosteroids
Adverse affects of psoralen + PUVA therapy
skin ageing, squamous cell cancer
mutagenic affect on keratinocytes
What is this?
SCC of the skin
sunlight, acintic keratoses, bowens, immunosuppression, smoking, marjolins ulcer
surgical excision
MOhs in high risk patients
What is this?
Malignant melanoma
superficial spreading = most common, young
nodular = most aggressive, old, bleeds
What is this?
seborrhoeic keratoses - basal cell papilloma
benign
can remove: curettage, cryosurgery & shave biopsy
What skin condition is associated with inflammatory disease?
pyoderma gangrenosum - insect like bite growing
lower legs
rheum, haem, pbc, granulomatosis with polyangitis
oral steroids, immunosuppression
Management of venous ulceration
compression bandagin
oral pentoxxifylline
Causes of erythema nodosum
infection e.g. strep, tb, brucellosis
systemic disease e.g sarcoid, ibd
malignancy
drugs e.g. penicillins, sulphonamides, cocp
pregnancy
Pigmentation of nail bed affecting proximal nail fold
Acral lentigninous melanoma
hutchinsons sign
arises in areas not associated with sun exposure
What is this?
erythema multiforme
infections
target lesions
HSV can lead to this rash other bacteria and drugs, connective tissue
What are the 4 D’s of pellagra
diarrhoea
dermatitis
dementia
death
think tb izonazid therapy
What is this?
lipoma
smooth, mobile, painless
if more than 5cm uss to rule out liposarcoma
% of body covered in burns required for IV fluids
10% children
15% adults
Benefit of using anti-virals for shingles
within 72 hrs
reduce incidence of post-herpetic neuralgia
What is leukoplakia
premalignant presents as white, hard spots on mucous membranes of mouth - common in smokers
Investigation of choice for allergic contact dermatitis
patch testing
What are side effects of ketoconazole
gynecomastia - supresses androgens
hepatotoxicity
severe papule rosacea treatment
topical ivermectin + oral doxycycline
Eczema herpaticum virus
Hsv type 1
causes of acanthosis nigricans
diabetes
gi cancer
obesity
pcos
acromegaly
cushings
hypothyroid
familial
prader willi
cocp, nicotinic acid
insuline resistance stimulates keratinocytes
urticaria first line
non sedating antihistamines
prednisolone if severe
Associated conditions with seborrhoeic dermatitis
HIV
parkinsons
scalp, periorbital, auricular and nasolabial folds regions
Otitis externa and blepharitis
First line for rosacea
topical brimonidine gel - predominant flushing but limited telangiectasia
sign of zinc deficiency
acrodermatitis red crusted lesions
alopecia
short
hypogonadism
hepatosplenomegaly
geophagia - eating clay
First line for candida infection
oral itraconazole
acne vulgaris in pregnancy
oral erthryomycin
what is livedo reticularis
discolouration of skin resulting from reduced bloodflow through the arterioles supplying cutaneous capillaries - linked to lupus
When should early intubation be considered with burns?
deep burns to face or neck, blisters or oedema of the oropharynxx
How does periorificial dermatitis present and how is it treated?
topical or oral antibiotics
steroids worsen symptoms
what is the most accurate diagram to assess burns area
lund and browder chart
Who should be transferred to a burns center? If respiratory problems?
burns involving the hand perineum, face and burs in 10% adults, 55 children
escharotomy
what is pompholyx
type of eczema that affects hands and feet
sweating
small blisters, pruritic,
cool compresses, emollients and topical steroids
first line treatment for scalp psoriasis
topical betamethasone valerate
keloid scars
dark skin
sternum most common site
intra lesional steroids e.g. triamcinolone
What do extensive burns cause?
secondary infection
ards
risk of ulcers
hypoalbuminiemia - plasma leakage into interstitial space due to loss of capillary integrity
Complications associated with psorialitic arthritis
CVS disease
What is erythema ab igne
caused by infrared radiation and commonly accosied with hot water bottles
can develop into squamous cell carcinoma
What drugs are linked with erythema multiforme?
penicillin, sulphonamides, carbamazepine, allopurinol, nsaids, oral contraceptive, nevirapine
Venous ulceration is typically seen above where
medial malleolus
How is Acne Vulgaris classified?
mild: open and closed comedones with or without sparse inflammatory lesions
moderate acne: widespread non-inflammatory lesions and numerous papules and pustules
severe acne: extensive inflammatory lesions, which may include nodules, pitting, and scarring
How is mild - moderate acne treated?
12 week combination therapy:
* topical adapalene with benzoyl peroxide (can be used mono)
* topical tretinoin with clindamycin
* topical benzoyl peroxide with clindamycin
How is moderate to severe acne treated?
12 week course of:
* mild treatment combos
* mild + either oral lymecycline or oral doxycycline
* topical azelaic acid + oral lyme/doxycycline
What should be considered about ABs when treated moderate to severe acne?
- Avoid tetracyclines: pregnant and under 12 (use erythromycin)
- Stop treatment at 6 months
- Topical retinoid co-prescribed to reduce AB resistance
- no topical + oral AB
Why is Minocycline not used in Acne vulgaris treatment now?
Irreversible pigmentation
What is a complication of long term AB use in Acne Vulgaris? What do you use if this occurs?
Gram-negative folliculitis
Trimethoprim
What is used as a alternative to oral ABs in Acne vulgaris treatment?
COCP (need topical agents with them)
What is the risk of using Dianette? Give its name as well
Co-cyprindiol
anti -androgen properties
increase risk of VTE
only give for 3 months
Which patients with Acne need refering to a dermatologist?
patients with acne conglobate acne: a rare and severe form of acne found mostly in men that presents with extensive inflammatory papules, suppurative nodules (that may coalesce to form sinuses) and cysts on the trunk.
patients with nodulo-cystic acne
Which Acne patients should be considered for referal to a dermatologist?
Not responding to 2 treatments
Not responding to AB
scarring
persistent pigmentary changes
psychological stress
What are the symptoms of Rosacea?
typically affects nose, cheeks and forehead
flushing is often first symptom
telangiectasia are common
later develops into persistent erythema with papules and pustules
rhinophyma (nose enlarge, red and bumpy)
ocular involvement: blepharitis
sunlight may exacerbate symptoms
What is this?
Rosacea
What is this?
Rosacea
What are the simple measures to manage Rosacea?
High factor sunscreen
How is Rosacea with predominant flushing treated?
Topical brimonidine (alpha-adrenergic agonist) gel if limited telangiectasia as well
Use as required, reduces in 30 minutes
How are mild to moderate papules in rosacea treated?
Topical Ivermectin
Alternative topical metronidazole / azelaic acid
When should referral be considered with Rosacea?
Symptoms not improve with management or has Rhinophyma
Laser therapy - telangiectasia
What are the main features of Seborrhoeic dermatitis?
Eczematous lesions on sebum rich areas:
1. scalp
2. periorbital
3. auricular
4. nasolabial folds
Otitis externa and blepharitis linked
What is this?
Seborrhoeic dermatitis
What is Seborrhoeic dermaittis associated with?
HIV
Parkinsons disease
What treatments are used for face and body management in Seborrhoeic dermatitis?
Topical fungal
Topical steroids - short period
What is Eczema Herpeticum?
HSV1 / 2
children with atopic eczema
rapid progressing rask
monomorphic punched out erosions (circular, depressed, ulcerated lesions)
IV aciclovir
What is this?
Eczema herpeticum
Monomorphic punched-out erosions
What is Erythema nodosum?
Inflammation of subcutaneous fat
tender, erythematous, nodular lesions
shins
6 weeks then resolves
heal with no scar
What are the causes of Erythema Nodosum?
Infection - Strep, TB, brucellosis
Systemic - sarcoid, IBD, behcets
Malignancy - lymphoma
Drugs - penicillin, sulphonamide, COCP
Pregnancy
What is this?
Erythema Nodosum
Tender, erythematous, nodular lesions
How is Chonic Plaque Psoriasis managed?
Emollients
1. Potent CS + Vit D analogue
* One in morning and one evening
2. 4 weeks, then 4 week break - Vit D twice daily
3. 8-12 weeks - CS twice daily or coal tar prep
4. Short acting dithranol
5. Phototherapy - psoralen + PUVA - ageing + SCC
6. Systemic therapy - methotrexate, ciclosporin, infliximab, ustekinumab
How is Scalp psoriasis managed?
Potent topical CS once daily 4 weeks
if not work, different forumulation
How is facial psorasis treated?
Mild CS once / twice 2 weeks
Risks of potent CS therapy
Skin atrophy
Striae
What is Dithranol?
Inhibtis DNA synthesis
wash off after 30 mins
burning and staining effects
Indications to refer burns to secondary care
all deep dermal and full-thickness burns.
superficial dermal burns of more than 3% TBSA in adults, or more than 2% TBSA in children
superficial dermal burns involving the face, hands, feet, perineum, genitalia, or any flexure, or circumferential burns of the limbs, torso, or neck
any inhalation injury
any electrical or chemical burn injury
suspicion of non-accidental injury
What are the features of Lichen Planus?
itchy, papular rash most common on the palms, soles, genitalia and flexor surfaces of arms
rash often polygonal in shape, with a ‘white-lines’ pattern on the surface (Wickham’s striae)
Koebner phenomenon may be seen (new skin lesions appearing at the site of trauma)
oral involvement in around 50% of patients: typically a white-lace pattern on the buccal mucosa
nails: thinning of nail plate, longitudinal ridging
Mainstay of treating Lichen Planus
Topical Steroids
Lichen Planus
Pyoderma gangrenosum first line
oral steroids
What is the commenst skin disorder found in pregnancy?
Atopic eruption
eczematous, itchy red rash
What is this?
Pruritic last trimester
abdominal striae
emollient etc
polymorphic eruption of pregnancy
Severe complication of Acne
Acme fulminans
Signs of hereditary haemorrhagic telangiectasia
pulmonary, hepatic, cerebral and spinal AVMs
What is the most common malignancy of the lower lip?
SCC
What type of surgery is least invasive?
Mohs micrographic surgery
Oral AB of choice to treat Erythrasma
Erythromycin
Main treatments for Actinic keratosis
Diclofenac / 5-fluorouracil
Raised white pearly edges
Basal cell carcinoma
what skin tumour has a rapid growth phase
keratoacanthoma
What is a common precipitant for pyogenic granuloma
trauma - bleeding
Treatment for athletes foot
Topical miconazole
What uncommonly causes eczema herpeticum
Coxsackie virus
What is Erysipelas?
Strep pyogenes
raised well defined border