Extra Derm Flashcards
What is a pyogenic granuloma?
overgrowth of blood vessels, red nodules, usually follows trauma
What is a keratoacanthoma?
common rapidly growing locally destructive skin tumour, can regress spontaneously with scarring or grow to be virtually indistinguishable from a SCC
Where are keloid scars most common?
the sternum
What is a keloid scar?
tumour like lesions that arise from the connective tissue of a scar and extend beyond the dimensions of the original wounds more common in areas of high skin tension eg. sternum
Treatment of keloid scar?
can be treated with intralesional steroids
What area tends to be more affected in vitligo?
peripheries
Presentation of scabies?
itch worse at night
characteristic irregular tracks in between digits of hands
nodules
neck and face tend to spared
Hirsutism vs hypertrichosis?
Hirsutism - hair growth in a male pattern
Trichosis - excess hairgrowth in any pattern
Risk of cryotherapy in darker skins?
can cause hypopigmentation
What is the oil drop sign?
it is indicative of nail psoriasis (doesnt occur in fungal infection)
it is an area of discolouration in the right fifth digit
Differential for psoriatic nail disease?
fungal nail infection
What is acanthosis nigrans? Links?
symmetrical brown, velvety plaques often found on neck, axilla and groin
predominantly linked to states of insulin resistance e.g. t2dm
Is pregnancy a contraindication to retinoids?
yes both topical and oral
AK vs Bowen disease?
Ak - varying forms of squamous dysplasia
bowens - squamous cell carcinoma in situ (some will say that bowen is only SCC on a sunexposed site some use it for all SCC)
Management of AK?
Sun protection
emollients
vigilance for skin cancers
cryotherapy
5-fluoruracil cream (efudex)
imiquimob (aldara)
for mild can sometimes use diclofenac
Explain what exclamation mark hairs are?
short fragile hair that is thinner at the base where it attaches to the body than the other end
occurs in alopecia areata
Prognosis of alopecia areata?
hair will regrow in 50% of patients by 1 year and 80-90% eventually
Give an example of a sedating antihistamine?
chlorphenamine
Give an example of 3 non-sedating antihistamines? Normal doses?
fexofenadine (120mg once daily), loratidine (10mg once daily), cetirizine (10mg once daily)
Features of a nodular BCC?
pearly nodule
telangiectasia
central ulceration
rolled edges
“rodent ulcer”
What is auspitz sign?
if scale removed on psoriasis there is pinpoint bleeding
What is erythema multiforme? What causes it?
this is a immune mediated, self limiting mucocutaneous condition
common precipitant is herpes simplex virus
other precipitants include: other viruses, medications and vaccinations
Presentation of erythema multiforme?
widespread, itchy, erythematous rash with classic target lesions, can get oral mucosa features
Management of erythema multiforme?
often not needed, can give symptom control e.g. antihistamine, local anaesthetic, steroid cream
Causes of erythema nodosum?
pregnancy
drugs - sulphonamides, cocp, penicillins
infections - strep, tb, brucellosis
malignancy - mainly leukaemias and lymphomas
systemic conditions - behcets, sarcoidosis, IBD
Presentation of fungal toenail infection?
presents similarly to psoriatic nails
toenails more likely to be infected than fingernails
Management of fungal nail infections?
do not need any treatment if patient is asymptomatic and not bothered by it
if < 50% nail affected and < 2 nails can use topical treatments however most will need oral terbinafine (which can cause liver damage)
Who is guttate psoriasis more common in?
more common in children and adolescents
often strep throat 2-3 weeks before
Prognosis and treatment of guttate psoriasis?
most resolve in 2-3 months
use topical psoriasis treatments
Guttate psoriasis vs pityriasis rosea presentation?
Guttate is classically following strep throat, pityriasis may be following URTI
Guttate is tear drop scaly papules, pityriasis is herald patch 1-2 weeks later followed by lesions which are more oval and red with scale refined to the outer aspect of the lesions
Guttate psoriasis can be on trunk and arms, pityriasis is classically a fir tree/ christmas tree distribution
guttate psoriasis lasts 2-3 months, treat with psoriasis treatment. Pityriasis last about 6 weeks and is self resolving.
Koebner phenomenon?
skin lesions seen at site of injury
clasically in psoriasis but can occur in other skin conditions too e.g. lichen planus
Presentation of lichen planus rash?
itchy, papular rash most common on the palms, soles, genitalia and flexor surfaces of the arms
polygonal in shape with white lines (wickhams striae)
koebner phenomenon
mucosal involvement - white lace pattern on buccal mucosa
Treatment of lichen planus?
potent steroids
Presentation of pityriasis rosea?
majority no prodrome but potentially recent viral infection
herald patch
1-2 weeks later, erythematous oval lesions with scale on outside
fir tree/ christmas tree distribution
Management of pityriasis rosea?
self limiting - 6 weeks
help with symptoms: topical steroids and oral antihistamines to reduce itch
What is seborrhoeic dermatitis?
chronic dermatitis - inflammatory reaction related to proliferation of normal skin inhabitant - fungus Malassezia Furfur (pityrosporium ovale)
Presentation of seborrhoeic dermatitis?
eczematous lesions on sebum rich areas e.g. scalp, periorbital, auricular and nasolabial folds
Management of seborrhoeic dermatitis?
scalp: OTC shampoos with zinc pyrithione e.g. head and shoulders, 2nd ketoconazole
face and body: topical antifungals e.g. ketoconazole
Explain what steven johnson syndrome and TENS is?
variants of same condition but SJS usually affects less of the skin
disproportional immune response to a trigger, there is then sheet like mucosal and skin loss
Triggers of SJS/ TENS?
Medications e.g. antiepileptics, NSAIDs, allopurinol, antibiotics
infections: CMV, HSV, HIV, Mycoplasma pneumonia
Presentation of SJS/ TENS?
prodrome of fever, sore throat, difficulty swallowing, sore red eyes, general aches and pains
then get sheet like mucosal and skin loss
medical emergency and can be fatal
When should antivirals be used in shingles?
in the majority of patients within 72 hours
Chronic plaque psoriasis guidelines?
NICE recommend a step-wise approach for chronic plaque psoriasis
regular emollients may help to reduce scale loss and reduce pruritus
first-line: NICE recommend:
a potent corticosteroid applied once daily plus vitamin D analogue applied once daily
should be applied separately, one in the morning and the other in the evening)
for up to 4 weeks as initial treatment
second-line: if no improvement after 8 weeks then offer:
a vitamin D analogue twice daily
third-line: if no improvement after 8-12 weeks then offer either:
a potent corticosteroid applied twice daily for up to 4 weeks, or
a coal tar preparation applied once or twice daily
short-acting dithranol can also be used
Scalp psoriasis guidelines?
NICE recommend the use of potent topical corticosteroids used once daily for 4 weeks
if no improvement after 4 weeks then either use a different formulation of the potent corticosteroid (for example, a shampoo or mousse) and/or a topical agents to remove adherent scale (for example, agents containing salicylic acid, emollients and oils) before application of the potent corticosteroid
What could SSSS be secondary to?
an initial impetigo
Presentation of SSSS?
widespread erythematous rash with tense bullae, nikolsky sign positive, usually children < 6 years old, spares the oral mucosa
Management of SSSS?
IV flucloxacillin and topic fusidic acid
What malignancy are renal transplant patients at risk of?
skin cancers such as SCC
Main advantage of antivirals in shingles?
reduces the risk of post herpetic neuralgia