Dermatology Flashcards
Acne: Rx
Mild/moderate: 12 week topical course… (AB/TC/BC)
- Adapalene + Benzoyl peroxide
- Tretinoin + Clindamycin
- Benzoyl peroxide + Clindamycin
Moderate-severe: 12 wk course (AB/ABO/TC)
- Adapalene + Benzoyl peroxide
- Adapalene + Benzoyl peroxide + oral antibiotic (Limecycline 408mg od / doxy 100mg od - do not use Abx alone!)
- Tretinoin + Clindamycin
Acne Rx don’ts
2
Do not use Abx alone
Do not combine topical and oral Abx together
Acne conglobata
Rare and severe form
Most commonly found in men
= extensive inflammatory papules, suppurative nodules and cysts
Needs dermatology referral
Eczema herpeticum
= disseminated herpes simplex infection
May present unwell - fever, malaise, LN, etc
Admit as complications such as eye/meningeal involvement
Burns: rule of 9s
In adults…
Head, arm = 9%
Leg, front, back = 18%
Palmar surface = 1%
Tinea incognito
= repeated immunosuppressant use (e.g. too much steroid) leads to extensive spread of fungal infection.
Therefore first management step —> stop steroid
Pityriasis versicolor
Often worse in summer months. Not infective
Rx:
- Ketoconazole 2% shampoo for 5 days
- Selenium sulphide 2.5% shampoo 7 days (off-label, not in pregnancy)
Pityriasis rosea
Common self-limiting
‘Herald patch’ often few days before
If in pregnancy, seek urgent advice re management
Otherwise settles in 2-3 months
No Rx needed (apart from symptomatic itch treatment)
Scabies
- by sarcoptes scabei
Transmitted through prolonged or close skin contact (e.g. handshake won’t cause transmission)
Sx:
- intense itching especially at night
Mx:
- Specialist advice if under 2 months old
- Topical insecticide twice, 1 week apart… Permethrin 5% dermal cream first-line (malathion 0.5% if permethrin inappropriate)
- Treat all household members, wash all linen/clothes, etc
- Itching can take a few weeks to settle
Can lead to secondary bacterial infection and ultimately sepsis
Lyme Disease
= Lyme borreliosis = bacterial infection caused by tick bite (think forests, woodlands, heathlands)
Sx:
- Classic rash of erythema migrants (red, flat, oval, bulls-eye appearance, at site of bite)
- Multisystemic effects if not treated (joints, neurological involvement)
IF Dx doubt - can use ELISA
Abx needed, e.g. doxy, amox, azithro (depends on extent of involvement, age, etc)
Pemphigus & Pemphigoid
Pemphigus:
- Group of AI disorders —> skin blistering
- Blistering is intra-epidermal - superficial and flaccid
- Skin painful (not itchy)
- Can do skin biopsy
- Max —> mainly systemic steroids
Pemphigoid:
- Chronic AI blistering skin disorder
- Blistering sub-epidermal - deep and tense
- Skin can be itchy
- Skin biopsy and direct immunofluorescence usually confirms Dx
- Mx includes strong topical steroids, oral steroids if severe
Erythema nodosum
Tender, red nodules….anterior of shin…mostly self-limiting
Associations include:
- Sarcoidosis, TB
- GI infection, IBD
- Drugs, e.g. sulphonamides, gold, oral contraceptives
Skin nodules
Elevated lesion on skin >5mm diameter (<5mm is papule)
Pyogenic granumola
Rapidly growing benign lesion, often following trauma —> proliferation of blood vessels
Painless, fleshy nodule that can bleed very easily
Mx:
Topical - e.g. imiquimod, timolol
Procedural - e.g. laser, curretage, excision
Actinic keratosis (aka solar keratosis)
UV light -induced dry skin lesions - flat, well demarcated, rough, dry, can bleed easily
Middle-aged/elderly, outdoor, fair skin
Can be pre-malignant (SCC)
Can monitor for change in some cases
Options:
- Cryotherapy, curretage, excision
- Topical Rx, e.g. 5-fu, salicylate
BCC
= rodent ulcer
Rolled edge
Slow local invasion
Routine derm referral - can be 2ww if concern about site/size, e.g. close to eye, nose, etc
SCC
Keratinised / scaly / ulcerated / crusted tumour
Usually head and neck
Consider 2ww
Bowen’s disease
= SCC in situ
Usually asymptomatic red, scaly patch
Rx options include:
- Freezing
- Curettage
- Excision
- Topical 5-fu cream
Melanoma: 7-point checklist
Refer 2ww if suspicious looking, or if score ≥3 on checklist…
MAJOR FEATURES (= 2 pts)
- change in size
- Irregular shape
- irregular colour
MINOR FEATURES (=1 pt)
- Largest diameter 7mm
- Inflammation
- Oozing
- Change in sensation
Melanoma: stages and Mx
Stages (0-4)
- Confined to epidermis
- No more than 2mm thick
- > 2mm thick (no LN)
- Spread to nearby LN
- Spread to other sites
Mx:
Surgery is main treatment (+/- sentinel node biopsy to check for LN spread)
Immunotherapy, radiotherapy, etc
Nail changes
Nail pitting - alopecia areata, psoriasis, eczema
Splinter haemorrhages (red/black long lines) - trauma, endocarditis, vasculitis
Onycholysis (detaches from nail bed) - psoriasis, hyperthyroid, fungal infection
Leuconychia (white nail) - Low albumin, CKD
Koilonychia (spoon-shaped nail) - Fe deficiency
Yellow nails - nicotine staining, fungal infection, psoriasis
Yellow nail syndrome (curved thick yellow nails) - associated with lymphoedema, exudative pleural effusions
Fungal nail infection
= onychomycosis
Can send nail clippings for M&C
Rx:
- Topical… Amorolfine nail lacquer once or twice weekly
- Oral… Terbinafine 250mg od first line (itraconazole/griseofulvin alternatives)
