Dermatology Flashcards
How long do you wait between courses of topical corticosteroids in patients with psoriasis?
4 weeks
What is the first line management of psoriasis?
Corticosteroid once daily plus vitamin D analogue once daily - at separate times. For up to 4 weeks
What is the second line management of psoriasis?
Vitamin D analogue twice daily
What are the features of a keratoacanthoma?
Common in old people. Looks like a crusty volcano, grows to become a crater with keratin in the centre
What are the features of a first degree burn?
superficial epidermal, red and painful, dry, no blisters
What are the features of a second degree burn?
partial thickness (superficial dermal): pale pink, painful, blistered, slow cap refill
partial thickness (deep dermal): typically white but may have non-blanching erythema, reduced sensation, painful to deep pressure
What are the features of a third degree burn?
White waxy/brown leathery/black, no blisters, no pain
How does the body respond to a burn?
release of inflammatory cytokines, sequestration of fluid into third space (fluid loss), immunosupression, bacterial translocation from gut, sepsis
What is the management of a burn?
cover with cling film - layered not wrapped
cleanse wound, Non-adhesive dressing
IV fluids and catheter
What is the first line management of acne?
topical adapalene with topical benzoyl peroxide
topical tretinoin with topical clindamycin
topical benzoyl peroxide with topical clindamycin
When do you give oral abx in acne?
when it is severe. must stop topical abx. given with topical retinoids or benzoyl peroxide
Who can start oral retinoids?
Dermatology - must be referred to start
What are the features of pityriasis rosea?
6-12 weeks, starts with a single pink/red oval patch, the spreads over body in ‘christmas tree’ pattern
What is the management of keratinised warts?
cryotherapy
What is the management of non-keratinised warts?
topical podophyllum
What is the management of scabies?
permethrin 5% cream
avoid close physical contact
all close contacts should be treated at the same time
What are the features of a branchial cyst?
- in children and teenagers
- brAnCHial - Anterior triangle, Cholesterol crystals
- does not transilluminate
What are the features of a pilar cyst?
sebum filled lesion around a hair follicle - may be filled with cheesy material
Which medications exacerbates psoriasis?
beta blockers, ACEi, NSAIDs, lithium
Which bacteria contributes to the formation of acne?
propionibacterium acnes
How is acne categorised into severity?
Mild - blackheads and whiteheads (no scars)
moderate - papules (no scars)
moderate-severe - pustules (scarring)
severe - cysts
What is the management of mild acne?
Topical benzoyl peroxide or salicyclic acid
What is the management of moderate acne?
topical doxycycline
What is the management of severe acne?
Isotretinoin, oral Abx
What is rosacea?
a type of acne that adults get, usually on nose and cheeks
What is the management of rosacea?
suncream. brimonidine gel to help with flushing. topical ivermectin. and if severe give oral doxycycline
How does ivermectin treat rosacea?
It is antiparasitic, so can remove mites that may cause it. It also causes vasoconstriction so reduces flushing
What causes eczema herpeticum
HSV 1 or 2
What is the management of eczema herpeticum?
IV aciclovir
What are the features of eczema herpeticum?
rapidly progressing rash, with punched out erosions, systemically become more unwell
How can you tell the difference between rosacea and SLE?
SLE spares the nasolabial folds
What is the most common malignancy in renal transplant patients?
squamous cell carcinoma of the skin, due to long term immunosuppression
What are the features of lichen planus?
itchy papular, purple rash, with white-lines polygonal pattern. Wickham striae on oral mucosa, thought to be autoimmune
What is the management of lichen planus?
topical steroids. benzydamine mouthwash if in mouth
What is erythema multiforme?
A type 4 hypersensitivity reaction triggered by infections/drugs (T-cells attack basal epithelial cells). Causes a mild/non-itchy rash - target lesions on hands and feet then torso
What is the management of erythema multiforme?
- treat causes - antivirals/stop meds/abx
- oral steroids
- usually self-resolves in a few weeks
What is a keloid scar?
A tumour-like lesion that arises from the connective tissue of a scar and extend beyond the original wound
What is the treatment of a keloid scar?
- if early, intra-lesional steroids
- excision - but careful not to create another keloid
Where do keloid scars typically form?
sternum, then shoulders/upper arms/earlobes
What causes seborrhoeic dermatitis?
Inflammatory reaction due to proliferation of a fungus called Malassezia furfur
What are the features of seborrhoeic dermatitis?
eczematous, scaly lesions on scalp, forehead, ears, nasolabial folds. Can have otitis externa and blepharitis
What is the management of seborrhoeic dermatitis?
topical ketoconazole, topical steroids for short periods
Which combination therapies should be used for mild-moderate acne?
for 12 weeks
topical adaptalene (retinol) with benzoyl peroxide
topical tretinoin with topical clindamycin
topical benzoyl peroxide with topical clindamycin
Which topical medications should be given with oral abx in acne?
retinoid or benzoyl peroxide. Do not give oral and topical Abx together
When are topical retinoids contraindicated?
in pregnancy
Why does polycythaemia cause itching?
There is more histamine release - this is worsened by exposure to water
What causes the delayed itching in scabies?
type 4 hypersensitivity reaction to the mites/eggs
What is the management of scabies?
1st line: permethrin 5%
2nd line: malathion 0.5%
When would you do a skin prick vs a skin patch test?
prick - if it goes in you, type 1 hypersensitivity (immediate)
patch - if it goes on you, type 4 hypersensitivity (delayed)
What are the features of squamous cell carcinoma of the skin?
a non-healing painless ulcer/nodule, fast growing, can be associated with a chronic scar or sun damage
What is the management of lichen sclerosis?
topical emollients and steroids
What are the features of guttate psoriasis?
white, scaly, erythematous patches on the trunk and limbs, usually triggered by a strep infection
What are the features of pityriasis rosea?
A self-limiting rash that presents with a herald patch on the torso, tree like distribution, can be after resp infection
What is the management of guttate psoriasis?
Most cases resolve spontaneously within 2-3 months
Topical agents as per psoriasis
UVB phototherapy
What is acanthosis nigrans?
hyperpigmentation and hyperkeratosis of the axilla, groin/neck. caused by diabetes, cancer, PCOS, cushings, obesity
What is the difference in appearance between a venous and an arterial ulcer?
venous - shallow ulcer, irregular edges, oedema and brown staining due to blood pooling, exudate, dull pain when leg down
arterial - deeper, with well-defined punched out edges, can be pale or have black areas of necrotic tissue, dry, sharp pain when leg up
what is the management of a venous ulcer?
Compression bandages, can give oral pentoxyphylline to improve blood flow
What is the first-line management of plaque psoriasis?
Topical potent corticosteroids, plus vitamin D analogue (OD at separate times)
What is the second-line management of plaque psoriasis?
Vitamin D analogue twice daily
How do you treat scabies household contacts?
permethrin, cover body in it, two treatments, 7 days apart
What is the management of hives?
non-sedating antihistamine (cetirizine/loratidine) for 6 weeks,
oral prednisolone 5 days, if severe or recurrent
When would you ultrasound a lipoma?
When it is bigger than 5 cm
What is the best treatment for telangiectasia in acne rosacea?
laser therapy
How long should you wait between periods of steroid treatments in patients with psoriasis?
4 weeks
What is the most important prognostic indicator for a superficial spreading melanoma?
Breslow Depth
