Derm Flashcards
What is this?
Acne vulgaris
How would you manage acne?
(Mild/Moderate/Severe/Pregnancy)
Mild - Moderate
- Comedonal acne = Topical Retinoid monotherapy (tretinoin, etc)
- Inflammatory acne = topical retinoid + antibiotic (clindamycin, erythromycin etc)
- Benzoyl peroxide adjunct
- Azelaic acid adjunct (reduces post-inflammatory hyperpigmentation)
Severe
-
Oral isotretinoin 5-6 months
- SE = headaches, decreased night vision, psychiatric events, teratogenic (do bhcg before)
- Oral corticosteroids (prednisolone) adjunct
Pregnancy
- Topical clindamycin or erythromycin or azelaic acid are safe
What is this? What is the usual presentation?
Basal Cell Carcinoma
- neoplasm related to sunlight exposure
- UV damage causes DNA damage in keratonicytes (damages P53 which leads to resistance of DNA-damaged cells to apoptosis)
Typically presents as papules/nodules with telangiectasias. Rolled borders, small crusts and non-healing wounds, pearly papules and plaques, mets in lungs/bones (uncommon)
How would you investigate a BCC?
Biopsy for dermatohistopathology
- shave biopsy for cosmetically challenging areas eg. face
- punch biopsy for cosmetically non-challenging areas
In vivo multiphoton microscopy
How would you manage a BCC?
Cosmetically challenging areas eg. face
- Mohs surgery
Non-Cosmetically challenging areas
- conventional surgery OR curettage followed by cautery
- Non surgical = cryosurgery, topical imiquimod for small superficial lesions, topical fluorouracil, Phototherapy for superficial low risk
Metastatic
Vismodegib
Patient comes in with a rash after buying a new ring. What do you think it is?
Contact dermatitis
- allergic or irritant skin reaction caused by an external agent
- typically
- There is allergic contact dermatitis and irritant contact dermatitis
- Urticaria common to both
What are some symptoms specific to Irritant Contact Dermatitis and Allergic Contact Dermatitis?
Allergic contact dermatitis is a delayed hypersensitivity reaction that requires prior sensitisation
- pruritus
- erythema
- vesicles and bullae
- Lichenoid lesions with metals and tattoo pigments
Irritant contact Dermatitis results from exposure to an agent that causes skin toxicity (no previous sensitisation required)
- typically on hands and face
- burning
- corrosion or ulceration
- pustules and acneiform lesions
How would you investigate contact dermatitis?
- patch testing to identify allergen
- Repeated Open Application Test (ROAT) or Provocative Use Test (PUT)
- Skin Biopsy
How would you treat contact dermatitis?
ACD
- avoid allergen
- 1st line = topical corticosteroids (hydrocortisone)
- 2nd line = topical calcineurin inhibitors (tacrolimus)
- emollient forms of topical corticosteroids eg. creams/ointments in chronic ACD if skin is dry
- gel/foam formulas in acute ACD when there is weeping and vesicles
ICD
- avoid future exposure
- moisturisers
- topical corticosteroids
- Dimethicone containing barrier cream to prevent future ICD
- soft white parrafin on affected areas
- cotton glove liners if irritant is gloves
a kid comes in with dry, pruritic skin on the extensure surfaces and flexures (antecubital/popliteal fossa, wrists).
He has a FHx of eczema, a MHx of asthma and allergic rhinitis.
What do you think it is?
Eczema
How would you manage eczema?
Symptom control
- emolients (improve barrier function of skin, reduce itching)
-
topical corticosteroids (reduce inflammation and pruritus)
- start low potency eg. hydrocortisone then titrate up if not working
- topical calcineurin inhibitors eg. pimecrolimus, tacrolimus
If previously mentioned medications don’t handle the symptoms…
- Coal tar
- UV light therapy
- Systemic immunosuppressants eg. oral ciclosporin, oral azathioprine, oral/subcut methotrexate, subcut dupilumab
- Antibiotic therapy if evidence of cutaneous infection
What is this? Why do you think that and what are the most common organisms?
Impetigo
- a superficial contagious blistering infection caused by Staph Aureus or Strep Pyogenes
- Can be bullous (usually s. aureus) or non-bullous
- presents as a yellowish to golden crusting (strep = darker and thicker crusts)
- erythema, pruritus, pain, fever if large scale
- risk factors = humidity, malnutrition, overcrowding
How would you manage impetigo?
Antibiotics + Skin Hygiene
- bullous = parenteral antibiotics, non-bullous = oral
- neonates = clindamycin
- superficial infection = topical mupirocin
- cutaneous infection = oral flucloxacillin
- Deep tissue spread = parenteral clindamycin
- MRSA = parenteral vancomycin
*
What is this? What is the typical patient presentation?
Melanoma
- a malignant tumour arising from melanocytes
- FHx of melanoma, MHx of sunburns, melanoma or atypical naevi
- sun exposure, excessive UV radiation exposure eg. sun bed use
- light eye colour or hair colour
How do you identify a melanoma?
A = asymetrical lesion
B = border irregularity
C = colour variability D = diameter \>6mm
E = Evolution
- atypical naevi
- persistent single nail melanonychia stria
- fixed lymphadenopathy
- Hutchinson’s sign
What is this? What is the typical presentation?
Psoriasis
- A hyperproliferative chronic inflammatory skin disorder
- (cells migrate from basal skin layer to stratum corneum in only a few days. silver scalaes are dead cells)
- erythematous, circumscribed scaly papules and plaques
- commonly on elbows, knees, extensor surfaces, scalp
What is this? How does it usually present?
Rosacea
- flushing, erythema, papules, pustules, telangiectases (superficial capillaries), sometimes roughened skin
- acne vulgaris can co-exist
- dry, burning or stinging sometimes
- ocular manifestations = chalazion, hordeolum, keratitis, etc.
- primarily affects central face but can extend to other parts of hte body
What is this? How would it typically present?
a Squamous Cell Carcinoma
- proliferation of atypical, transformed keratinocytes with malignant behaviour.
- precursor lesions are actinic keratosis
- Keratonicytes undergo uncontrolled proliferation due to malignant transformation of cells due to exposure to the UV-B region of UV light
- Risk factors = UV exposure, old age
- Patients usually have evidence of sun damage (wrinkles), tender or itchy non-healing wound, erythematous papules or plaques, dome-shaped nodule
What is this? What is the typical patient history/presentation?
Urticaria
- erythematous, blanching, oedematous, painless pruritic lesions
- typically last about 24 hours and leave no residual marks
- often IgE mediated (eg. food trigger)
- typically have associated angioedema (swelling of face, tongue, lips)
- sometimes stridor if patient has laryngeal angio-oedema
- Hx = exposure to drug trigger, food trigger, viral infection, insect bite
