MRCP2 Flashcards
Causes of acanthosis nagricans?
type 2 diabetes mellitus
gastrointestinal cancer
obesity
polycystic ovarian syndrome
acromegaly
Cushing’s disease
hypothyroidism
familial
Prader-Willi syndrome
Drugs that cause acanthosis nagricans?
combined oral contraceptive pill
nicotinic acid
Pathophysiology of acanthosis nagricans?
insulin resistance → hyperinsulinemia → stimulation of keratinocytes and dermal fibroblast proliferation via interaction with insulin-like growth factor receptor-1 (IGFR1)
Comodone + top closed
Whitehead
Comodone + top open
Black head
What lesions form when follicles burst and cause inflammation?
Papules
Pustules
excessive inflammation in acne sees what?
nodules
cysts
Acne vulgaris: what skin lesiosn are seen?
White head + blackheads
Papules + Pustules
Nodules and cysts
How to differeniate between acne and drug induced acne?
Drug induced acne typically is monomorphic
Acne + Fever ?
Acne fulminans
Treatment of acne fulminans ?
Hospital
Steroids
Features of mild acne?
mild: open and closed comedones with or without sparse inflammatory lesions
Features of moderate acne?
moderate acne: widespread non-inflammatory lesions and numerous papules and pustules
Features of severe acne?
severe acne: extensive inflammatory lesions, which may include nodules, pitting, and scarring
Management of acne?
- Single topical treatment (topical retinoids, benzoyl peroxide)
- Topical combination treatment (topical antibiotic, benzoyl peroxide, topical retinoid)
- Oral antibiotics + (Topical treatments)
tetracyclines: lymecycline, oxytetracycline, doxycycline - OCP + (Topical treatments)
- Isotretanoin
Choice of antibitoic in acne + pregnant ?
Erythromycin
Why is minocycline no longer used ?
Irreversible pigmentation
Management of gram negative folliculitis?
high-dose oral trimethoprim is effective if this occurs
How long should antibitoics be prescribed in acne - and why?
3 months
Risk of gram negative folliculitis
Management of actinic keratosis?
fluorouracil cream: typically a 2 to 3 week course.
topical diclofenac: may be used for mild AKs.
topical imiquimod: trials have shown good efficacy
cryotherapy
curettage and cautery
Exclamation mark hairs
Alopecia arreta
Is alopecia arrest reversible
Yes
Treatment of alopecia arreta?
topical or intralesional corticosteroids
topical minoxidil
phototherapy
dithranol
contact immunotherapy
wigs
What is bowens disease?
precursor to squamous cell carcinoma
red, scaly patches
often 10-15 mm in size
slow-growing
often occur on sun-exposed areas
Management of bowens disease?
topical 5-fluorouracil - BD for 4 weeks
Cryotherapy
Excision
Does pemphigoid have mucosal involvement?
No
Skin biopsy in pemphigoid?
immunofluorescence shows IgG and C3 at the dermoepidermal junction
Management of pemphigoid?
oral corticosteroids
oral corticosteroids
What are campbell de morgan spots?
erythematous, papular lesions
typically 1-3 mm in size
non-blanching
not found on the mucous membranes
What is Chondrodermatitis nodularis helicis?
Painful nodule on ear cartilage
Benign
Caused by pressure
Management of chondrodermatitis nodularis helicis?
‘ear protectors’ may be used during sleep
include cryotherapy, steroid injection, collagen injection
Features of chronic plaque psoriasis?
erythematous plaques covered with a silvery-white scale
typically on the extensor surfaces such as the elbows and knees. Also common on the scalp, trunk, buttocks and periumbilical area
clear delineation between normal and affected skin
plaques typically range from 1 to 10 cm in size
if the scale is removed, a red membrane with pinpoint bleeding points may be seen (Auspitz’s sign)
Pathophysiology of dermatitis herpetiformis?
Associated with coeliac disease
IgA deposition into skin
Causes blistering rash
Skin biopsy finding of dermatitis herpetiformis?
deposition of IgA in a granular pattern in the upper dermis
Management of dermatitis hepertiformis?
gluten-free diet
dapsone
What is a dermatofibroma?
Growth of dermal dendritic histiocyte cells, often following a precipitating injury
Benign
Features of discoid eczema?
round or oval plaques on the extremities
the lesions are extremely itchy
central clearing may occur giving a similar appearance to tinea corporis
What is the other name for discoid eczema?
Nummular eczema
What is eczema herpeticum?
severe primary infection of the skin by herpes simplex virus 1 or 2.
Appearance of eczema herpeticum?
monomorphic punched-out erosions (circular, depressed, ulcerated lesions) usually 1–3 mm in diameter are typically seen.
Management of eczema herpeticum?
Can be life threatening in children
IV aciclovir
Prognostic markers for severe eczema?
onset at age 3-6 months
severe disease in childhood
associated asthma or hay fever
small family size
high IgE serum levels
Management of eczema?
emollients
topical steroids
UV radiation
immunosuppressants: e.g. ciclosporin, antihistamines and azathioprine
Mild topical steroid?
Hydrocortisone 0.5-2.5%
Moderate topical steroid?
Betamethasone valerate 0.025% (Betnovate RD)
Clobetasone butyrate 0.05% (Eumovate)
Potent topical steroid?
Fluticasone propionate 0.05% (Cutivate)
Betamethasone valerate 0.1% (Betnovate)
Very potent topical steroid?
Clobetasol propionate 0.05% (Dermovate)
What is erythema multiforme?
Hypersenitivity reaction
Divided into:
- Erythema multiforme minor
- Erythema multiforme major
How to differentiate between erythema major and minor?
Major: Mucosal involvement
How to differentiate between seborrheic keratosis and malignant melanoma?
Pseudo-comedones and pale spots help distinguish seborrhoeic lesions from malignant melanomas
presence of dark pigmented pin-prick spots, sometimes described as pseudo-commodones
Management of dermatitis herpetiformis ?
Topical dapsone
What is dermatitis herpetiformsi associated with?
IDA –> coaeliac
Fixed drug erruption vs discoid eczema?
Fixed drug eruptions however tend to occur within 24 hours of starting the drug and disappear after 10 days.
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
What is erythema nodsum?
inflammation of subcutaneous fat
typically causes tender, erythematous, nodular lesions
Causes of erythema nodosum?
infection:
streptococci
tuberculosis
brucellosis
systemic disease:
sarcoidosis
inflammatory bowel disease
Behcet’s
malignancy/lymphoma
drugs:
penicillins
sulphonamides
combined oral contraceptive pill
pregnancy
Cause of erythroderma?
eczema
psoriasis
drugs e.g. gold
lymphomas, leukaemias
idiopathic
Erythroderma psoriasis
What can trigger an erythroderma psoriasis ?
Withdrawl of steroids
Causative organism of fungal nail onychomycosis?
dermatophytes
account for around 90% of cases
mainly Trichophyton rubrum
yeasts
account for around 5-10% of cases
e.g. Candida
Investigation of fungal nail onychomycosis?
nail clippings +/- scrapings of the affected nail
Management of fungal nail onychomycosis?
if limited involvement (≤50% nail affected, ≤ 2 nails affected, more superficial white onychomycosis): topical treatment with amorolfine 5% nail lacquer; 6 months for fingernails and 9 - 12 months for toenails
oral terbinafine is currently recommended first-line; 6 weeks - 3 months therapy is needed for fingernail infections whilst toenails should be treated for 3 - 6 months
Treatment of candida onychomycosis?
Candida infection: oral itraconazole is recommended first-line; ‘pulsed’ weekly therapy is recommended
papular lesions that are often slightly hyperpigmented and depressed centrally + Dorsum of hands / feet?
Grannuloma annular
Associations of granuloma annular?
Diabetes mellitus
What precipitates a guttate psoriasis flare?
streptococcal infection 2-4 weeks prior to the lesions appearing.
Management of guttate psoriasis?
topical agents as per psoriasis
UVB phototherapy
tonsillectomy may be necessary with recurrent episodes
‘Tear drop’, scaly papules on the trunk and limbs
Guttate psoriasis
Herald patch?
Pityriasis rosea
raised oval lesions with a fine scale confined to the outer aspects of the lesions.
oval lesions running parallel to the line of Langer.
Pityriasis rosea
Fir tree
Pityriasis rosea
Inheritance of HHT?
Autosomal dominant