Dermatology Flashcards
Acne non-pharmacological management
- Avoid heavy cleansing
- Avoid cheap soaps/washes
- Avoid excessive scrubbing/exfoliating
(All cause MORe irrigation to epidermis, blocks sebaceous glands)
- Use non-comdeogenic and non-acnegenic creams, cosmetics and sunscreen instead
- Do not squeeze/pick pimples
- Balanced, healthy diet
- Minimise exposure to hot/humid environments (steam, kitchens, spas)
- Smoking cessation
Acne pathophysiology - 4 steps
- Abnormal increased proliferation of follicular keratinocytes –> follicular plug
- Increased sebum production from sebaceous follicles
- Proliferation of microorganisms within sebum
- Inflammation
Acne mild treatment (3 steps)
- OTC products - benzoyl peroxide 5%
- –> Topical retinoid (e.g adapelene 0.1% gel or cream, tretinoin 0.025% cream)
Apply 2nd nightly for 2/52 then nightly
Review after 6/52
(TERATOGENIC!!!) - –> Topical combination
comedonal - Benzoyl peroxide+adapalene 2.5%+0.1% gel, once daily
inflammatory - benzoyl peroxide+clindamycin 5%+1% gel, once daily
R/v after 6/52
Acne moderate treatment (men, if pregnant, women)
- Doxycycline 50mg-100mg daily 6/52 then r/v
- Minocycline 50mg-100mg daily 6/52 then r/v
If pregnant
1. Erythromycin 250-500mg BD 6/52 then r/v
Women
1. COCP; ethinylestradiol+cyproterone
Acne severe treatment (1) + main risk + side effects (6)
Isotretinoin (refer Derm)
Main risk teratogenicity Cat X - recommend double contraception
A/e’s
- Dry skin
- Epistaxis
- Photosensitivty
- Myalgias
- headaches
- LFT derangement
Features on history to assess for skin cancer risk assessment
- Ethnic background, skin phototype (Fitzpatrick skin type I-II high risk), red hair
- Immunosuppression
- Recent change in lesions
- Symptomatic lesions (bleeding/pruritis?)
- PHx of skin Cancer/removal of suspicious lesion
- Tendency to sunburn
- Occupational risk
- Time spent outside/outdoors
>100 naevi or >10 dysplastic naevi
Tinea cruris management
Topical antifungal (terbinafine 1% gel) once or twice daily for 7-14 days
+/- hydrocortisone cream
Impetigo Rx in endemic settings
Bactrim 160/800mg BD 3 days
(IM Benzathine Benpen also 1st line, 1.2 million units)
Pyoderma gangrenosum associated conditions (3)
- IBD
- Rheumatoid arthritis
- Myeloid blood dyscrasias (e.g leukaemia)
Melasma risk factors
- UV exposure
- Hormones (oestrogen/prog) - e.g during pregnancy/COCP/MHT
- Soaps/cosmetics
- Heat exposure
- Can be a/w thyroid disease
Melasma Rx
- Kligman’s formula (gold standard) - combo of hydroquinone/tretinoin/dexamethasone, BD for 3 weeks
- Azelaic acid 5-20% BD
- Tranexamic acid 2-5% BD
- Hydroquinone cream 2-5 % daily
- High fever 3-5 days (+/- URTI sx, lymphadenopathy) –> rash appears as fever subsides
- Rash starts on trunk then spreads to neck, limbs and face
Roseola infantum (HHV6-7)
When can Hand Foot Mouth disease kids go back to school
Blisters stop being infective once dried (but can continue shedding in stools for a month)
Plaque psoriasis management options - broad (3)
- Tar (6% LPC/3% salicylic acid cream) - generally 4 weeks
- Corticosteroids - generally methylpred for 2-6 weeks
- Calcipotriol - nails/palsm
Psoriatic nail changes (5)
- Oil spots
- Horizontal ridges
- -Onycholysis*
- -Subungal hyperkeratosis*
- -Pitting - last 3 overlap with onychomycosis*
Onychomycosis treatment
Terbinafine 250mg daily 12 weeks toenails, 6 weeks fingernais
2nd-line alts - fluconazole, itraconazole
Vitiligo history (risk factors) (4)
PHx/FHx autoimmune disease - thyroid, coeliac, alopecia areata
-STRONG a/w thyroid disease - consider testing thyroid Ab
FHx vitiligo
Hx melanoma
Emotional stress
Impetigo non-endemic Rx
- Localised
- Multiple sores
- Pen allergy delayed
- Pen allergy immediate
- Mupirocin 2% ointment TDS 5/7
- Fluclo/diclox 500mg QID 7/7
- Cefalexin 500mg QID 7/7
- Bactrim 160/800 BD 3 days
Allergic contact dermatitis Ix options
- Usage test (apply substance to cub. foss BD for 7 days)
- Patch testing - refer Derm
- Skin scrapings for microscopy/fungal culture? tinea manuum?
Contact dermatitis management principles (4)
- Avoidance –> Protection –> Substitution –> Treatment
- Protection - PPE, gloves, barrier creams
- Regular emollients after work
- Topical steroids/calcineurin inhibitors
- If severe/acute –> ?PO steroids 25-50mg daily for 1 week, taper over 2 weeks
?Diagnosis
Abrupt onset hair loss, patchy
Age <40 y.o
PHx/FHx autoimmune disease/atopy?
Exclamation mark hairs
Positive hair pull test
Alopecia areata
?Diagnosis
Usually in kids
Gradual or abrupt onset
Localised hair loss
?Contact with animals/travel
Broken hairs, comma hairs
Tinea capitis
(needs oral antifungals - terbinafine or griseofulvin. Start treatment before mCS results back)
?Diagnosis
Abrupt onset
Diffuse hair thinning
2ndary to iron deficiency/thyroid disease/post-partum
Areas of hair regrowth
Positive hair pull test
Telogen effluvium
Trichofolliculoma - rare benign adnexal tumour
DDx
- Epidermal cyst
- Soft fibroma
- Keloid
- Chondroma
- Dilated pore of Winer
Guttate psoriasis Rx options (3)
- Same as for psoriasis of trunk & limbs*
- LPC6% + salicylic acid3% BD for 1 month
- Methylpred 0.1% (Advantan)/mometasone 0.1% daily for 2-6 weeks
- Calcipotriol + betamethasone foam 50+500, daily for 6 weeks
Urticaria triggers (7)
- Allergy (occurs w/ exercise, w/ assoc. abdo pain/SOB, within 1-2 hrs of meal)
- infections
- Meds - e.g penicillins
- Contact allergy to plants/animals
- Foods
- Bites and stings
- Physical (cold, pressure)
Scabies Rx
- Adults/kids >5 y.o
- Crusted scabies
- Permethrin 5% from neck down, nails w/ nialbursh, leave on for 8 hours, repeat in 7 days
- Oral ivermectin 200mcg/kg stat, repeat in 7 days
- Benzyl benzoate 25% topical from neck down, repeat 7 days
–Treat all household contacts
–Hot wash clothes/bedsheets
(apply creams to face and scalp if central/northern Aust, infants/elderly)
Crusted - refer ID/hospital
Biopsy margins for:
- Suspected melanoma
- Lentigo maligna
- SCC/BCC
- excisional biopsy w/ 2mm margin
- shave excision of entire lesion if possible
- SCC/BCC - excisional biopsy with 3-5mm margins
Folliculitis Rx
-Spa bath folliculitis - causative agent & Rx
- Warm compress, mupirocin 2% ointment BD for 5/7
- Pseudomonas aeruginosa, cease contact w/ water supply/irritant
Erythrasma risk factors (7)
Warm climate
Excessive sweating
Diabetes
Obesity
Poor hygiene
Advanced age/immunocompromise
Skin of colour
Normal commensal bacterium, cornyebacterium
Erythramsa Rx (2)
- Fusidate sodium 2% ointment, BD for 14 days
- Clarithromycin 1g oral stat dose
Pityriasis versicolour - causative organism, Rx options (4)
Malassezia yeast
- Econazole 1% overnight for 3 nights
- Ketoconazole 2% shampoo top, daily for 3-5 mins & wash off, for 5 days
- Miconazole 2% shampoo top, daily for 10 mins & wash off, for 10 days
- Selenium sulfide 2.5% shampoo, daily for 10mins/overnight for 7-10 days
Unresponsive = fluconazole 400mg stat dose
Common warts Rx (2)
Plane warts Rx (1)
- Salicylic acid up to 40% w/v, daily until cleared
- Cryotherapy - three freeze-thaw cycles of 10-20 secs every 2-4 weeks
Typically resolve spontaneously 6-12 mths
-Topical retinoid
Imiquimod/fluorouracil doses for SCC
Imiquimod 5% cream nocte up to 5 nights per week for up to 6 weeks
Fluorouracil 5% cream once or twice daily, 2-4 wweeks
Referral thickness for melanoma to MDT
Definitive management (margins)
- Refer all >1mm thickness/uncertainty in histopath dx to multidisciplinary melanoma team
- Definitive Rx of in situ melanoma = wide local excision with 5-10mm margin
- Invasive = margins of 10-20mm
- sentinel lymph node biopsy if thickness >1mm
Follow-up advice aspects post-melanoma treatment (3)
- Peak risk period is within first 3 years
- Educate on self-skin examinations
- 3 monthly skin check if stage 3, 12-monthly skin check if stage 1
Onycomychosis DDx (7)
- Nail psoriasis
- Lichen planus
- Yellow nail syndrome
- Traumatic onychodystrophy
- Alopecia areata
- Age-related nail dystrophies
- Subungal melanoma/SCC
BCC low risk management options (other than biopsy/excision) (4)
-High risk management options (2)
- Other management options only if superficial and low risk area
- Imiquimod 5% 6 weeks
- Curettage and cautery
- Photodynamic therapy
- Cryotherapy
- High risk Rx
- Referral to specialist
- RTx or Moh’s surgery
Follow-up intervals post-SCC treatment
-Every 3-6 months after excision for first 2 years
Then 6-12 monthly
(Recurrence is common in first 2 years)
Follow-up intervals post-SCC treatment
-Every 3-6 months after excision for first 2 years
Then 6-12 monthly
(Recurrence is common in first 2 years)
Oral leukoplakia DDx (6)
- Candidiasis
- Lichen planus
- Nicotine stomatitis
- Habitual cheek/lip biting
- Frictional keratosis
- SLE
Psoriasis RFs/flares (7)
Drugs (b-blockers, ACEIs, NSAIDs)
Infections (strep/HIV)
Skin trauma
Stress
Alcohol
Sunburn
Hormonal factors (pregnancy)
Mild recurrence of oral mucocutaneous herpes - immunocompetent pt Rx options (2)
Episodic therapy
- aciclovir 5% cream topically, 5 times daily for 5 days
- Famciclovir 1500mg oral stat
infrequent, severe recurrence of oral mcuocutaneous herpes - immunocompetent Rx options (3)
- Famciclovir 1500mg stat dose
- valaciclovir 2g oral BD for 1 day
- Aciclovir 200mg, 5 times daily for 5 days
Erythema nodosum treatment
Bed rest
NSAIDs
Elevation/compression
Pred 25mg daily 2/52 then taper, if severe
Wound or ulcer history questions (6)
- Smoking status
- Tetanus immunisation
- Immunosuppressant conditions/meds
- Compliance w/ treatment (e.g diabetes)
- Symptoms of infection (e.g fever)
- Presence of PVD/arterial disease
