Dermatology Flashcards
Imiquimod uses?
External genital and perianal warts - 3 times a week, up to 16 weeks until wart clears
Superficial basal cell carcinoma where surgery is considered inappropriate (primary treatment) - 5 times a week (on consecutive days). Treat for 6 weeks.
Actinic keratoses of the face and scalp (sun spots) - 3 times a week . Treat for 4 weeks. If any lesions are still present 4 weeks later, repeat 4‑week course
How quickly after sun exposure does the erythema appear?
2-6 h, max severity after 24h,
Resolution with peeling of the skin occurs over 4-7 days
May be confused with a photosensitive drug eruption
What are the types of skin cancer?
basal cell carcinoma
squamous cell carcinoma
melanoma (the most dangerous form of skin cancer)
What is the presentation of Basal Cell Carcinoma?
Most lesions occur on head & neck (50%)
Metastasis is rare but can cause extensive localised damage
Usually begin as small, shiny, firm, almost clear to pink in colour, raised growths
Over time (months to years) visible blood vessels may appear on surface which can break open and form a scab
Slow growing tumours
Treatment options for Basal Cell Carcinoma?
First line treatment – surgical removal (except superficial BCC)
Superficial BCC treatments: cryotherapy (primary lesions only), PDT and topical imiquimod
Imiquimod cream 5% - apply at night 5 x weekly for 6 weeks. Wash off in morning.
Advanced BCC treatment - vismodegib (Erivedge)
Vismodegib 150 mg capsules once daily ( binds to smoothened (SMO) transmembrane protein, inhibiting the hedgehog signalling pathway which is abnormally activated in some cancers
PBS Authority Required (check requirements on the PBS)
Presentation of Squamous cell carcinoma?
Mainly occur on areas heavily exposed to the sun – head, neck, backs of hands, limbs
Tender lesion that can appear suddenly and grow rapidly OR grow slowly over weeks to months
Characterised by its thick, scaly, irregular appearance and overtime raised and firm (wart-like appearance)
May develop in normal skin but more likely to develop in damaged skin
Grow more rapidly than BCC – therefore treat ASAP
Treatment for Squamous Cell Carcinoma?
First-line surgical treatment with a 3-5mm margin
Radiotherapy if surgery not appropriate
Presentation of Melanoma?
Asymmetry: one half different from the other
Border: usually irregular
Colour: Varies within the lesion.Pigment is largely or completely absent in hypomelanotic melanoma
Diameter: greater than 6mm. Sometimes melanomas are diagnosed when smaller than this – an increasing diameter is more important than size.
Evolution: changing or evolving
How to manage sunburn?
Limited data suggest that nonsteroidal anti-inflammatory drugs, oral and/or topical corticosteroids may reduce the severity of an acute sunburn
Cool compresses may offer symptomatic relief
Apply cool damp cloth to affected areas
Increase water intake: prevent dehydration
Anaesthetic spray (Paxyl®, Solarcaine®) relieves pain
After sun cream or gels (emollients)
Cooling gels - water based (Solosite®, Solugel®)
Aloe vera - clinical evidence limited
Use as pure a gel as possible
How to treat actinic keratosis?
Fluorouracil 5% cream (Efudix®) -
Apply once or twice daily for 2-4 weeks (face) or 3 – weeks (arm & legs)
Imiquimod 5% cream -Aldara®
Apply at night 3 x weekly for 3-4 weeks. Wash off in morning
OR
Apply at night 3 x weekly, continuously for up to 16 weeks
Diclofenac 3% gel - Solaraze®
Apply bd usually for 60-90 days. Pea-sized amount (0.5g) to cover lesion 5cm x 5cm
Methyl aminolevulinate/
5-aminolevulinic acid - Metvix®, Alacare®
1 x session of photodynamic therapy
Patch: Apply for 4hrs then expose to PDT
Cream: Apply a thin layer of cream to affected area using a non-metal applicator or rubber gloves, then (no more than 30 minutes later) expose the lesions to daylight outdoors for 2 hours.
What are the risk factors for cutaneous drug eruptions?
Female
Hx drug reaction
Recurrent drug exposure
HLA type (genetic)
Certain disease states (HIV)
What are the types of cutaneous drug reactions?
Exanthematous Drug Eruptions
Fixed Drug Eruptions
Photosensitivity
Toxic Epidermal Necrolysis and Stevens-Johnson syndrome
Describe Exanthematous Drug Eruptions
Also known as morbilliform drug eruption or maculopapular drug eruption
It is the most common of all cutaneous drug eruptions (~90-95%)
Occurs within 7-10 days (may be longer) after starting the offending agent but may occur faster (eg within 1-3 days) if it is a re-exposure.
Usually starts on the trunk and then spreads to the limbs and neck – it is bilateral and symmetrical.
Can be accompanied by itch and mild fever.
In an adult, this type of reaction is usually from a medication.
In a child, this type of reaction may be viral
Antibiotics are often the culprit
Resolves in a few days to a week after the medication is stopped.
The surface skin may peel off
Describe Fixed Drug Eruptions
An adverse reaction that characteristically appears in the same site/s with re-exposure to a drug (this is why it’s called ‘fixed’)
Occurs up to 2 weeks after first exposure or faster onset after subsequent exposure.
Usually a well-defined round or oval patch of redness and swelling, sometimes with a blister.
Common offending medications include paracetamol, NSAIDs, tetracycline, sulfonamides, salicylates, metronidazole, hyoscine butyl bromide and yellow food colouring. This list is NOT exhaustive.
Lesions resolve days to weeks after the drug is stopped
Unbroken lesions can be treated with a potent topical steroid.
Broken lesions can be protected with a dressing until it is healed
Lesions may be painful especially if they are located on the mucosa
Describe Photosensitivity reaction to a drug?
Drug induced photosensitivity is classified as either photo-toxic or photo-allergic
Photo-toxic can look like a sunburn-type redness
Photo-allergic features similar to allergic contact dermatitis with a dry, bumpy or blistering rash
Generally prominent on sun-exposed sites, e.g. face, hands, V of the neck (may be spread to unexposed areas in photoallergy)
The rash may or may not be itchy.
The drugs are also known as photosensitisers
Common offending agents include antibiotics, NSIADs, diuretics, retinoids, sulfonylureas, phenothiazine antipsychotics and others.
Sometimes the photosensitising properties are used clinically (eg prior to photodynamic therapy for the management of some skin cancer
Describe Toxic Epidermal Necrolysis and Stevens-Johnson syndrome
Toxic Epidermal Necrolysis and Stevens-Johnson syndromes are now believed to be variants of the same condition.
They are rare, acute, serious and potentially fatal skin reactions in which there are
sheet-like skin and mucosal loss.
Although very rare and unpredictable, antibiotics are the most common cause but other medications (eg allopurinol, NSAIDs, nevirapine, paracetamol, anticonvulsants) can also be involved.
There may be a prodromal illness for several days that appears like a flu-like illness.
Symptoms may occur before the direct onset of the illness
Flu-like symptoms include fever, sore throat, runny nose, cough, sore eyes, conjunctivitis, general aches and pains.
Then an abrupt onset of a tender, red skin rash or blisters, usually starting on the trunk and spreading to the face and limbs. The spread may occur rapidly over several hours to a few days.
The blisters then merge to form sheets of skin detachment.
Mucosal involvement is prominent and severe.
eyes, lips, mouth, pharynx, genital area, respiratory tract, GI tract.
The patient is usually very ill, very anxious and in considerable pain.
How to treat Exanthematous Drug Eruptions?
identifying the causative agent (establish a drug timeline)
Emollients
Potent topical steroids (refer to GP)
maybe oral antihystamines
How to treat Photosensitivity?
Stop suspected drug (if possible): if can’t be stopped - advise on strict sun protection strategies for the duration of treatment
Consider changing time of drug administration e.g. night, or maybe reduce dose
Moderate-potent topical corticosteroids (referral required) +/– wet compresses
Emollients for symptomatic relief
Analgesia (NSAIDs may reduce severity if given <48 hours for phototoxic reactions)
How to treat TENS / SJS?
Management includes immediate referral to hospital, identification and cessation of the suspected offending agent.
ICU care may be needed.
High mortality 10-30% and possible long term sequelae kin scarring, pigment changes to the skin, joint contractures, lung disease, eye problems which may lead to blindness.
Types of dermatitis/eczema (2 exogenous, 5 endogenous)
Exogenous :
Irritant contact dermatitis
Allergic contact dermatitis
Endogenous :
Atopic dermatitis
Seborrheic dermatitis
Discoid dermatitis
Asteatotic dermatitis
Pompholyx / dyshidrotic dermatitis
Treatments for dermatitis? (OTC/S3)
Soap substitutes
Emollients/moisturisers
Antihistamines for the itch
Tar/ ichthammol
Topical CS:
- hydrocortisone 0.5 -1 %
- clobetasone
- mometasone furoate 0.1%
Colloidal oatmeal
Treatments for dermatitis S4?
Compounded coal tar
potent CS
calcineurin inhibitor - pimecrolimus (facial!)
PDE4 inhibitor - crisaborole
biologicals
What questions you ask for dermatology symptoms?
Where and when?
▪ Other symptoms?
▪ Occupation?
▪ Medical Hx?
▪ Travel?
▪ Patient’s thoughts?
▪ Description?
▪ Distribution
▪ Arrangement
▪ Feel of the lesion
▪ Temperature of the lesion
▪ Recent trauma?
Which are mild to moderate CS?
hydrocortisone
betamethasone valerate (0.02 - 0.05%)
clobetasone
desonide
triamcinolone
Which are potent and very potent CS?
betamethasone dipropionate
betamethasone valerate 0.1%
mometasone
clobetaSOL
What do you use for seborrheic dermatitis?
Non-medicated shampoos
Keratolytics
Antifungals
Mild CS
Topical pimecrolimus
What are the treatment lines for dandruff?
- Daily shampoo
- Anti yeast shampoo 2/week
- CS lotion at night for 7 days (betamethasone dipropionate, methylprednisolone aceponate, mometasone furoate)
+/- coal tar emulsion or LPC + salicylic acid
- CS lotion at night for 7 days (betamethasone dipropionate, methylprednisolone aceponate, mometasone furoate)
- CS shampoo
What do you use for seborrheic dermatitis on face and trunk?
- combination topical CS + antifungal
hydrocortisone + clotrimazole/miconazole - separate CS + topical antifungals (2w)
- weak LPC od, 2 w
Crisaborole?
PDE4 inhibitor
Mild to moderate atopic dermatitis
Use in 2y+
Pimecrolimus
Calcineurin inhibitor
Mild to moderate eczema
Second line for facial if CS fail or cannot be used
Applied bd for 3-6 weeks
Use sun protection!
Used also for Psoriasis (not approved in Australia, but used off label and used OS)
What immunosuppressants are used off-label for atopic dermatitis?
- methotrexate - once a week
- ciclosporin
- azathioprine
- mycophenolate
- prednisolone
What are the types of psoriasis?
Plaque
Scalp
Nail
Guttate
Flexural
Describe plaque psoriasis
The most common type of psoriasis
Well demarcated, pink plaques with silvery scale
Common sites include outside of elbows, knees, sacrum and lower back
Lesions may be single or numerous
May be itchy but commonly asymptomatic
Describe scalp psoriasis
Generally thick patches that can cover the entire scalp and may extend slightly beyond the hairline (facial psoriasis)
May cause temporary, mild hair loss in severe cases
May be the first or only site of psoriasis, but may co-exist with other forms of psoriasis.
Describe nail psoriasis
Pitting, yellowing and ridging on nails
Onycholysis may be present (separation of the nail from the nail bed)
Most patients also have chronic plaque psoriasis
Many patients also have psoriatic arthritis
It arises from within the nail matrix
Can affect one or more nails
Usually have some psoriasis in other areas
Course of the condition varies over time
Describe Guttate Psoriasis
‘Gutta’ is Latin for drop
guttate psoriasis looks like shower of red, scaly tear drops on the body.
Usually on trunk, upper arms and thighs
Lesions are pink but scaling may be less noticeable
Occurs at any age but most often in teenagers and young adults
May be triggered by a streptococcal throat infection
Has a good chance of spontaneous resolution
Describe Flexural Psoriasis
Localised to body folds and genitals (eg armpits, groin, under the breasts, navel, natal cleft, penis, vulva)
Appearance may be slightly different because of the moist nature of the skin folds
Sometimes called inverse psoriasis
Smooth, well-defined patches – may be difficult to diagnose as it often has little scale, but may be shiny.
May be colonised by Candida species
List the therapies used for psoriasis
Emollients
Keratolytics
Coal Tar Preparations
Topical CS
Dithranol
Vit D analogues (calcipotriol)
calcineurin inhibitor (pimecrolimus)
phototherapy
systemic therapy
Give examples of keratolytics
Salicylic acid (2-6%)
apply 2-3 times a day, can be used under occlusive dressing
can be used to allow other medications to penetrate
Give examples for Coal Tar preparations
Crude Coal Tar
LPC (liquid coal tar)
1% crude = 5% LPC
Reduce epidermal thickness, reduce itch, mildly antiseptic
Most common therapy for psoriasis?
Topical corticosteroid
What is Dithranol? What is it used for?
Aka anthralin
Acts as an antimitotic used in thick plaque psoriasis
Washed off after 30 mins
Specialist use
Keep in dark place
Once it turns brown/purple it is no longer effective
Use gloves as it stains
Can be used on the scalp but not for blonde hair
What is calcipotriol used for and what does it come in combination with?
Vit D analogue, comes in combo with betamethasone; used for psoriasis
Avoid use on face and skin folds
Protect area from sunlight
What kind of therapy can be used for psoriasis?
Phototherapy
-narrow band UVB - inhibits immune and inflammatory pathways
-photochemotherapy - methoxsalen +UVA
- do not apply sunscreen!
What immunosuppressants are used in psoriasis?
Methotrexate - once a week!
Ciclosporin
What systemic therapies can be used in psoriasis?
-Immunosuppressants (methotrexate, ciclosporin)
-Retinoids (acitretin - oral) -> take with foods
-PDE-4 inhibitor (apremilast - oral) - works as immune suppressant
-Biologicals - mAbs eg. ustekinumab, infliximab, adalimumab
What are some aggravating factors for psoriasis?
Skin trauma (injuries such as cuts, abrasions, sunburn)
Smoking - encourage smoking cessation as it also leads to cardiovascular disease
Excessive alcohol
Stress, stressful event
Streptococcal throat infection - more likely to associated with acute guttate psoriasis in young adults
Obesity
Sun exposure in ~10% (more often, sun exposure is beneficial)
Medications (eg lithium, beta blockers, antimalarials, NSAIDs and others). As per eTG, severe flares, (including pustular psoriasis) can be triggered by lithium, chloroquine, hydroxychloroquine, and interferon alfa. Severe flares can also be triggered by withdrawing systemic or potent topical corticosteroids.
Name some dermatophyte infections
Tinea pedis
Tinea corporis
Tinea unguium
Tinea capitis
Tinea cruris
Tinea manuum
Name some yeast infections
Pityriasis versicolour
Oral candidiasis
Vaginal candidiasis
Napkin candidiasis
Treatments for tinea unguium?
amorolfine nail lacquer - 9 to 12 months
bifonazole and urea
Systemic treatments for tinea?
Oral terbinafine
Fluconazole
Itraconazole (if terbinafine is not tolerated)
Griseofulvin (less effective but cheap) - take with food
What treatments are for pityriasis versicolour?
Topical antifungals - econazole, ketoconazole, miconazole
Anti-infective- selenium sulfide shampoo
oral antifungals - fluconazole, itraconazole
What treatments are for oral candidiasis?
Miconazole gel S3
Nystatin drops S3
Amphotericin lozenges S4
What treatments are for vulvovaginal candidiasis?
Intravaginal clotrimazole, miconazole, nystatin
Oral fluconazole S3
Boric acid for candida glabrata
What treatments are for napkin candidiasis
Topical CS - hydrocortisone or if severe methylprednisolone aceponate or triamcinolone acetonide
Topical antifungal +/- zinc - miconazole, clotrimazole, nystatin
Treatment options for impetigo (school sores)?
Topical mupirocin
Oral di/flucloxacillin
alternative - cephalexin, trimethoprim+sulfamethoxazole
Remote areas- S pyogenes - Benzathine penicillin or trimethoprim+sulfamethoxazole
Risk factors for acne
Stress -> more skin oil, blocking pores and causing breakouts, increase in hormones
High GI foods can worsen, low GI can improve
Exercise reduces insulin output which contributes to acne, and reduces stress, but sweat can worsen it, so wash face
Medications: CS, progesterones, testosterone, anabolic steroids, antiepileptics, lithium, azathioprine
Hormones - make sebaceous glands produce more sebum; can be aggravated in PCOS
What are the key processes that lead to acne formation?
Increased sebum production
Follicular hyperkeratinisation
Microbial colonisation
Inflammatory processes
What are OTC treatments for acne?
Benzoyl peroxide
Salicylic acid
azelaic acid
niacinamide
What is benzoyl peroxide used for and why?
Treatment of comedonal and mild acne
Antibacterial activity.
Mildly comedolytic.
Can be used with oral agents EXCEPT with oral retinoids.
Begin at lower strength.
Can bleach clothes, towels ect.
What is azelaic acid and used for?
Mild acne
Alternative to benzoyl peroxide
Less irritation than benzoyl peroxide
May cause hypopigmentation or photosensitisation
What is salicylic acid used for
Mild acne and psoriasis.
In acne:
Antibacterial activity
Mildly comedolytic.
Anti-inflammatory properties
What topical S4 medications can be used for acne?
Antibiotics:
clindamycin and erythromycin
*clindamycin also comes in combo with benzoyl peroxide and tretinoin
Retinoids:
Tretinoin
Adapalene
Apply for 6 weeks then review.
Can combine with other topical/oral treatments.
Teratogenic risk.
What systemic S4 treatments can be used for acne?
- antibiotics
Doxycycline, minocycline, erythromycin - Can take 3-6 months for response - hormonal treatments
COC or progesterone only - cyproterone, drospirenone, desogestrel
Spironolactone - option for women, diuretic, anti-androgen if COC not suitable, not to be used in pregnancy - systemic retinoid - isotretinoin
Course is 6 to 9 months and causes prolonged remission in most patients.
Potent teratogen, it must be managed by specialists.
MOA: Modulate cell proliferation and differentiation and decrease inflammation.
Avoid topical treatments (increases local irritation).
Effective contraception essential in females during treatment and for 1 month after stopping.
What are the contributing factors for rosacea?
Genetic
Compromised skin barrier that allows microorganisms to penetrate and stimulate an inflammatory response
Altered immune response including changes in skin and gut microbiome
Vascular hyper-reactivity to extremes - temperature, spices etc.
Features of rosacea?
Recurrent flushing of the skin
Broken capillaries under the skin (telangiectasia)
Pustules and papules
Thickening of skin on the nose - mostly in men
Persistent swelling of face and eyelids
What are the types of rosacea?
ETR - redness due to prominent blood vessels
Papulopustular - inflammatory papules and pustules
Phymatous rosacea - Enlarged unshapely nose with prominent pores
Ocular rosacea - Eye irritation and blepharitis, Red, sore or gritty eyelid margins including papules and styes
What treatments can be used for rosacea?
Papulopustular:
Metronidazole gel or cream - antimicrobial and anti-inflammatory (long term treatment and maintenance; improvements after 2-4 weeks)
Azelaic acid - less effective, but work for papulopustular as it inhibits growth of cutibacterium acnes
Ivermectin - anti-inflammatory
Oral antibiotic - doxycycline, erythromycin
Ocular:
antimicrobials- as above,
ocular lubricants,
good hygiene, referral
Erythematotelangiectatic:
brimonidine gel - temporary effect (12h), can cause rebound erythema
laser treatment
What are the available treatments for warts?
Salicylic acid (alone or in combination up to 40%)
Podophyllum Resin prepared as paint, wash off after 6h
Podophyllotoxin is more effective than podophyllum resin for anogenital warts. , no need to wash off
Imiquimod -three times a week until all warts are cleared (to a maximum of 16 weeks)
Cryotherapy
Ablative therapy
Referral points for warts
No response to treatment
Multiple or widespread
Bleeding, changing colour, itch
Px over 50, 1st time warts
All px with anogenital - women will need cervical exam
Facial warts in delicate areas- eyelids
Px with diabetes as treatment can damage skin
List some treatments for head lice
Malathion
Pyrethrins - all ages
Isopropyl myristate
Benzyl alcohol
Herbal or essential oils\
Wet combing
off label ivermectin if resistant
With all repeat after 7 days
List treatments for scabies
permethrin cream - wash after 8 h, repeat after 7 days
benzyl benzoate lotion- apply diluted for kids, was after 24h, repeat after 7 days
topical crotamiton cream - apply for 2-5 days
resistant scabies- oral ivermectin
- sedating antihistamines for itch
