Dermatology Flashcards
(72 cards)
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
