Dermatology Flashcards
How does rosacea present?
Flushing of the forehead, nose and cheeks
Telangiectasia
May be papules and pustules
Can progress to rhinophyma
What is mild rosacea?
Erythema or telangiectasia only
How is mild rosacea managed?
Lifestyle changes eg avoid sun, wear sunscreen, avoid exercise, avoid alcohol
If erythema only and no telangiectasia - topical Brimonidine gel
What is moderate rosacea?
Limited papules and pastules
How is moderate rosacea managed?
Topical metronidazole
Also topical azelaic acid
What is severe rosacea?
Extensive papules and pustules
How is severe rosacea managed?
Oral antibiotics e.g. oxytetracycline
How can telangiectasia be managed in rosacea?
Laser therapy
What is the stepwise approach to managing acne?
1) topical treatment e.g. benzoyl peroxide/retinoid/salicylic acid/azelaic acid
2) combination topical treatment
3) topical antibiotic - usually a tetracycline/erythromycin
4) oral antibiotics - usually a tetracycline (e.g. doxycycline) unless pregnant/breastfeeding/under 12
5) oral COCP in women
6) oral isotretinoin
What needs to be co-prescribed with an oral antibiotic in acne?
A topical benzoyl peroxide/retinoid to reduce chance of antibiotic resistance
Which antibiotic is most commonly used in acne?
A tetracycline e.g. doxycycline, oxytetracycline
Where does eczema most commonly affect?
In infants - cheeks
In older children and adults - flexures SYMMETRICAL!!
What is the first line management for eczema?
Emollients
Mild eczema/eczema on face - mild topical steroid
Moderate to severe eczema - moderately potent or potent topical steroid
What is an example of a mild topical steroid?
0.1% Hydrocortisone
What are examples of moderate potency topical corticosteroids?
Betamethasone 0.025% or Clobetsone 0.05%
What are examples of potent topical steroids?
Fluticasone 0.05%
Betamethasone 0.1%
What is an example of a very potent topical steroid?
Clobetasol 0.05%
What type of hypersensitivity reaction is allergic contact dermatitis?
Type IV
How does psoriasis present?
Well defined red scaly patches on the skin
Elevated plaques
Overlaying white/silver scale
Symmetrical distribution
What are nail changes seen in psoriasis?
Pitting
Oncholysis (lifting)
What is the stepwise management of psoriasis in primary care?
1) topical potent corticosteroid + vitamin D analogue (both once daily)
2) vitamin D analogue twice a day
3) topical potent corticosteroid twice a day or coal tar preparation twice a day
How can psoriasis be managed in secondary care?
Ultraviolet B phototherapy
Immunosuppressants
What is the first line immunosuppressant in psoriasis?
Methotrexate
How is scalp psoriasis managed?
Potent topical corticosteroid once daily for 4 weeks
How is psoriasis on the face/flexures/genitals managed?
Mild to moderate potency corticosteroid
What are non dermatological causes of pruritus?
Liver disease Iron deficiency anaemia Chronic kidney disease Polycythaemia Lymphoma
What is dermatitis hepatiformis?
Itchy vesicular lesions on extensor surfaces - knees, elbows, buttocks
Associated w/ coeliac
Which dermatological condition is associated with coeliac disease?
Dermatitis herpetiformis
What is the treatment for dermatitis herpetiformis?
Gluten free diet
Dapsone
Which medications exacerbate psoriasis?
Beta blockers
Lithium
Antimalarials
NSAIDs
ACE inhibitors
Alcohol
What is eczema herpeticum and how does it present?
Viral infection that usually presents in children with atopic eczema
Rapidly worsening, painful eczema with clustered blisters.
May be assocated fever and systemic illness
Which virus causes eczema herpeticum?
HSV1/HSV2
How is eczema herpeticum treated?
Aciclovir - oral or IV
What is erythema multiforme?
A hypersensitivity reaction usually triggered by infection (usually HSV or Mycoplasma)
Which infections most commonly trigger erythema multiforme?
HSV
Mycoplasma pneumoniae
How does erythema multiforme present?
Target lesions
Sharply demarcated lesions
Initially on back of hands and feet, then also on torso
Hypersensitivity reaction most commonly caused by HSV
How is erythema multiforme treated?
No treatment needed - self limiting
What is erythema nodosum?
An inflammatory disorder of the subcutaneous fat
How does erythema nodosum present?
Bilateral tender erythematous modular lesions usually on the shins
What are causes of erythema nodosum?
Associated with IBD, TB, sarcoidosis, pregnancy
How is erythema nodosum treated?
Self-limiting
Can give NSAIDs
What is erythroderma?
More than 95% of the skin is involved in a rash
What are complications of erythroderma?
Hypothermia
Dehydration (fluid loss)
How does pityriasis rosea present?
- Starts with a ‘Herald patch’ on trunk
2. Then scaly patches all over body
How is pityriasis rosea treated?
Self limiting - resolves in 6 weeks
Which rash starts with a herald patch and then goes on to a fir tree rash?
Pityriasis rosea
What is guttate psoriasis?
A rash precipitated by a streptococcal infection (usually 2-4 weeks before)
How does guttate psoriasis present?
Scaly tear drop papules on the trunk
How is guttate psoriasis managed?
Usually resolves spontaneously within 2-3 months
Can use topical psoriasis agents
What is pityriasis versicolour?
Cutaneous fungal infection
Which fungus causes pityriasis versicolour?
Melassezia furfur
How does pityriasis versicolour present?
Hypopigmentation patches on the skin
Scaly
May be itchy
How is pityriasis versicolour treated?
Ketoconazole shampoo
What is a pyogenic granuloma?
A red/brown spot which rapidly progresses to a raised lesion
May bleed
Often caused by trauma
How can a strawberry naevus be treated?
Topical timolol (beta blocker)
What is pyoderma gangreosum?
Rapidly enlarging painful ulcer
What is pyoderma gangreosum associated with?
IND
RA
SLE
Myeloproliferative disorders
How is pyoderma gangrenosum managed?
Oral steroids
What causes seborrhoeic dermatitis?
Melassezia furfur
Which areas does seborrhoiec dermatitis affect?
Scalp
Auricular folds
Nasolabial folds
What conditions is seborrhoeic dermatitis associated with?
Parkinson’s
HIV
How is seborrhoeic dermatitis on the scalp treated?
- OTC head and shoulders/t gel
2. Ketoconazole shampoo
How is seborrhoeic dermatitis on the face/body managed?
Topical Ketoconazole
What is actinic keratosis/solar keratosis?
Crusty scaly lesions which occur due to sun exposure
Which type of skin cancer can actinic keratosis progress to?
Squamous cell carcinoma
How is actinic keratosis managed?
Fluorouracil cream or or Imiquimod
What is seborrhoeic keratosis?
Melanocytic lesion usually in older people
No treatment needed
Which sign is seen in alopecia areata?
Exclamation mark hair
How to distinguish bulbous pemphigoid and pemphigus vulgaris?
Bullous pemphigoid = itchy bullae which do not affect the mucosa
Pemphigus vulgaris = non itchy, painful blisters which can affect the mucosa
Which condition is associated with bullous pemphigoid?
Parkinson’s
How are bullous pemphigoid and pemphigus vulgaris treated?
Oral steroids
What are stevens johnson syndrome and toxic epidermal necrolysis?
Systemic reactions almost always due to drug reactions
Which drugs cause SJS/TEN?
Never Press Skin As It Can Peel (NIkovsky’s Sign)
NSAIDs Phenytoin Sulphonamides Allopurinol/Anti-epileptics IV Ig COCP Penicillin
How does stevens johnson syndrome present?
Well demarcated maculopapular rash
Target lesions
Systemic features
How does TEN present?
Scalded appearance
How is TEN treated?
Supportive care
IV Immunoglobulins
What are the two main causative organisms for cellulitis?
Strep pyogenes
Staph aureus
What is first line treatment for mild to moderate cellulitis?
Flucloxacillin (clarithromycin if penicillin allergic)
How is severe cellulitis treated?
co-amoxiclav/cefuroxime/Ceftriaxone
When should you admit someone with cellulitis?
If they are:
Under 1 year
Frail
Significant systemic upset - tachycardia/tachypnoea/hypotension
Sepsis
Necrotising fasciitis
Immunocompromised
Facial cellulitis
What is the difference between cellulitis and necrotising fasciitis?
Necrotising fasciitis = pain out of keeping with physical features
Necrosis
Purple rash
Most common = Fournier’s gangrene (perineum)
What is the main risk factor for necrotising fasciitis?
Diabetes
Especially those treated with -gliflozin drugs
Which organism causes staphylococcal scalded skin syndrome?
Staph aureus
How is staphylococcal scalded skin syndrome managed?
IV flucloxacillin
Which conditions cause Acanthosis nigricans?
T2DM GI cancer Obesity PCOS Acromegaly Cushing’s
What are the four levels of burn and how do they present?
- Superficial epidermal - red and painful
- Superficial dermal - may be blistered
- Deep dermal - white
- Full thickness - white/necrosis, no pain
When do you admit for burns?
All deep dermal/full thickness burns
Superficial deems if they are more than 3% TSBA (2% in children)
Which patients with burns need IV fluids?
Adults - deep dermal/full thickness more than 15%
Children - any burn more than 10%
What does antivirals in shingles prevent?
Post herpetic neuralgia
Which is the most common skin cancer?
Basal cell carcinoma
How does basal cell carcinoma present ?
Pearly, flesh coloured papule
Telangiectasia
May ulcerate
What are risk factors for squamous cell carcinoma?
Actinic keratosis
Bowen’s disease
Immunosuppressed
Smoking
How does squamous cell carcinoma present?
Usually a small module which enlarged then ulcerates
Usually presents as a non healing ulcer
How is a squamous cell carcinoma diagnosed?
Incisional (punch) biopsy
How is squamous cell carcinoma managed?
Excisional biopsy
If less than 20mm - 4mm margins
If more than 20mm - 6mm margins
How does bowens disease present ?
Slow growing Red scaly patches in sun exposed areas
How is bowens disease managed?
Topical 5-fluorouracil
2 times a day for 4 weeks
Cryotherapy
What is the most common type of malignant melanoma?
Superficial spreading
Which is the most aggressive type of malignant melanoma?
Nodular
What is the major criteria for malignant melanoma?
Change in shape
Change in size
Change in colour
Which type of malignant melanoma is most likely to bleed/ooze?
Nodular
What is the minor criteria for malignant melanoma?
Diameter > 7mm
Inflammation
Oozing/bleeding
Altered sensation
How is a suspicious malignant melanoma managed?
Full thickness excisional biopsy
What is the most important prognostic factor for malignant melanoma?
Thickness (depth) of lesion (Breslow thickness)
What margins are needed for squamous cell carcinoma?
If lesion is less than 20mm – 4mm margins
If lesion is more than 20mm – 6mm margins
How does Lichen plans present?
Itchy, papular rash on palms/soles/genitalia - purple in colour
Wickham’s striae (white line pattern)
Koebner phenomenon (new lesions at the site of trauma)
Oral involvement
How is lichen plansus managed?
Potent topical corticosteroids
How does tinea present?
Erythematous, scaly, well demarcated lesion with a pale centre
How is ringworm treated?
Clotrimazole/miconazole/fluconazole (topical)
How is a fungal nail infection treated?
If singular nail can use Amorolfine nail lacquer
Otherwise - oral terbinafine
How does molloscum contagiousum present?
Flesh coloured papule with a central dimple
How is molluscum contagiousum managed?
No treatment required
What is Athlete’s foot and how does it present?
Tina infection (tinea pedis)
Scaling/flaking/itchy between toes
How is Athlete’s foot treated?
Topical antifungal
What is the first line for hyperhidrosis?
Aluminium chloride
Which type of melanoma can affect areas not exposed to the sun?
Acral lentiginous melanoma
What is Nikolsky’s sign?
Seen in SJS/TEN
Skin peels when it is touched
Spider naevi vs. telangiectasia?
Spider naevi fill from the centre
Telangiectasia fill from the edge
What are causes of spider naevi?
Liver disease
Pregnancy
COCP
Rosacea vs. malar rash in SLE?
SLE – spares nose
What are the 4 types of psoriasis?
Plaque psoriasis
Flexural psoriasis
Guttate psoriasis
Pustular psoriasis
Where are keloid scars most common?
Sternum
In which conditions is the Koebner phenomenon seen in?
Koebner phenomenon = new lesions at site of trauma
- psoriasis
- vitiligo
- warts
- lichen planus
- lichen sclerosus
- molluscum contagiosum
Which drugs cause gynaecomastia?
Spironolactone Ketoconazole Isoniazid Methyldopa Verapamil
How can you tell the difference between pyogenic granuloma and amelanocytic melanoma?
Pyogenic granuloma = Trauma
How does scabies present?
Widespread pruritus
Linear burrows on sides of fingers/between fngers
Track marks between finger webs
How is scabies managed?
Permethrin cream
If crusted/difficult to treat = oral ivermectin
What can help with itching in scabies?
Crotamiton cream
When can children with impetigo return to school?
48 hours after commencing treatment or once all lesions have crusted
What is hereditary haemorrhagic telangiectasia?
Autosomal dominant condition
1) Epistaxis
2) Telangiectasia- esp over mucuous membranes
3) Visceral lesions
4) Family history
Which pregnancy rash spares the umbilicus?
Polymorphic eruption of pregnancy
Which pregnancy rash has fluid filled blisters around the umbilicus?
Pemphigoid gestationitis
