Dermatology Flashcards
ACNE VULGARIS
What is the pathophysiology of acne vulgaris?
- Obstruction of the pilosebaceous follicles with keratin plugs with colonisation by anaerobic bacterium Propionibacterium acnes
ACNE VULGARIS
How is acne categorised based on clinical presentation?
- Mild = open (blackheads) + closed (whiteheads) comedones ± sparse inflammatory lesions
- Mod = widespread non-inflammatory lesions, numerous papules + pustules
- Severe = extensive inflammatory lesions, may include nodules, pitting + scarring
ACNE VULGARIS
What is the first line management of acne vulgaris?
- Single topical (non-Abx) therapy e.g., topical retinoid adapalene, benzoyl peroxide
ACNE VULGARIS
What is the second line management of acne vulgaris?
- Topical combination therapy = benzoyl peroxide and clindamycin
ACNE VULGARIS
What is the third line management of acne vulgaris?
What are the exceptions to this?
How long can you do this treatment for?
- PO tetracyclines (lyme/doxycycline) WITH topical combination therapy of retinoid + benzoyl peroxide to reduce Abx
- Avoid tetracyclines in pregnancy (use erythromycin), breastfeeding + children <12m
- Single PO Abx used for maximum of 3m
ACNE VULGARIS
Other than PO Abx, what else may be considered?
What is the secondary care management of acne vulgaris, an important contraindication and some side effects?
- COCP with topical combination therapy
- PO isotretinoin > C/I in pregnancy
- SE = dry skin, depression, teratogenic, increased triglycerides.
ATOPIC DERMATITIS (ECZEMA) What is the pathophysiology of atopic dermatitis?
- Defects in the skin barrier allows entrance to irritants, microbes + allergens which create an immune response + so inflammation
ATOPIC DERMATITIS (ECZEMA) What is the clinical presentation of atopic dermatitis?
- Erythematous, dry, itchy patches over the flexor surfaces, face + neck
- May be on extensor surfaces in younger children
- May have PMHx/FHx of atophy (asthma, hayfever)
ATOPIC DERMATITIS (ECZEMA) What are two key complications of atopic dermatitis?
- Opportunistic bacterial infection
- Eczema herpeticum
ATOPIC DERMATITIS (ECZEMA) How do opportunistic bacterial infections present? What is the management?
- Staph. aureus = increased erythema, yellow crust, pustules
- PO flucloxacillin or admit for IV if severe
ATOPIC DERMATITIS (ECZEMA) How does eczema herpeticum present? What is the management?
- Widespread vesicular lesions with pus + generally unwell secondary to HSV/VZV
- Same day derm, PO or IV aciclovir
ATOPIC DERMATITIS (ECZEMA) What is the maintenance management for atopic dermatitis?
- Avoid irritants
- Simple emollients (E45)
- Soap substitutes
ATOPIC DERMATITIS (ECZEMA) What is the flare management fo atopic dermatitis?
- Thicket emollients
- Topical steroids (weakest for shortest period) Help Every Budding Dermatologist = Hydrocortisone > Eumovate > Betnovate > Dermovate.
- Wet wraps with thick emollient to keep moisture overnight
- PO ciclosporin if very severe
ATOPIC DERMATITIS (ECZEMA)
What are some side effects of topical steroids?
What should you tell patients about applying emollients and topical steroids?
- Thinning of skin, telangiectasia, bruising
- Apply emollients first, wait 30m, then topical steroids
PSORIASIS
What can trigger psoriasis?
- Stress
- Trauma
- Steroid withdrawal
- Alcohol
- BALI drugs = Beta-blockers, Anti-malarials, Lithium, Indomethacin (NSAIDs)
PSORIASIS
What are the 5 types of psoriasis?
- Chronic plaque #1
- Flexural
- Guttate
- Pustular
- Erythrodermic
PSORIASIS
Explain the presentation of…
i) chronic plaque psoriasis?
ii) flexural psoarisis?
i) Well-demarcated, red scaly patches on extensor surfaces, sacrum + scalp
ii) Smooth, erythematous plaques without scale in flexures + skin folds
PSORIASIS
Explain the presentation of…
i) guttate psoriasis?
ii) pustular psoriasis?
ii) erythrodermic psoariasis?
i) Transient, multiple tear drop lesions 2w post-group A strep infection
ii) Multiple petechiae + pustules on palms + soles
iii) Extensive erythema + systemically unwell > emergency admit
PSORIASIS
What are some signs seen in psoriasis?
- Nails = pitting, onycholysis, subungual hyperkeratosis
- Koebner phenomenon = new plaques of psoriasis at sites of skin trauma
- Auspitz sign = small points of bleeding when plaques scraped off
PSORIASIS
What are some complications of psoriasis?
- Psoriatic arthritis
- Metabolic syndrome
- CVD
- VTE
- Psychological distress
PSORIASIS
What is the general management of psoriasis?
- All patients use an emollient to reduce scale + itch
- Avoid triggers
PSORIASIS
What is the first line management of psoriasis?
What is the second line management of psoriasis?
What is the third line management of psoriasis?
- Potent corticosteroid TOP OD plus vitamin D TOP OD (calcipotriol)
- Vitamin D TOP BD
- Potent corticosteroid BD or coal tar preparation BD
PSORIASIS
What is the secondary care management of psoriasis?
- UVB phototherapy
- Systemic = methotrexate > ciclosporin
- Biologics like infliximab, adalimumab
PSORIASIS
What is the mechanism of action of vitamin D analogues?
What effect does this have?
What patient safety information is crucial?
- Reduce cell division + differentiation > reduced epidermal proliferation
- Reduce scale + thickness of plaques but NOT erythema
- Can be used long-term unlike steroids but AVOID in pregnancy
CONTACT DERMATITIS
What are the two types of contact dermatitis and what classically causes them?
- Irritant (common) = non-allergic reaction typically detergents
- Allergic = T4 hypersensitivity reaction typically head following hair dyes
CONTACT DERMATITIS
How does irritant contact dermatitis present?
How is it managed?
- Erythema, usually in the hands
- Emollients, topical corticosteroids
CONTACT DERMATITIS
How does allergic contact dermatitis present?
How is it managed?
- Acute weeping eczema affecting margin of hairline
- Topical potent corticosteroid
BASAL CELL CARCINOMA
What is a basal cell carcinoma (BCC)?
What is the epidemiology and most common type?
What are some risk factors?
- Locally invasive, slow growing tumour of epidermal keratinocytes (mets rare)
- # 1 cancer in Western world, nodular BCC most common
- Sun burn, increasing age, fair skin, immunosuppression, FHx
BASAL CELL CARCINOMA
What is the clinical presentation of BCC?
- Classically sun-exposed sites = head + neck
- Pearly, flesh-coloured papule with surface telangiectasia
- Rolled edges
- Older lesions = centre necrotic/ulcerated (Rodent ulcer)
BASAL CELL CARCINOMA
What is the management of a BCC?
- Routine derm referral
- Surgical excision, curettage, cryotherapy, topical imiquimod, radiotherapy
SQUAMOUS CELL CARCINOMA
What is a squamous cell carcinoma (SCC)?
What is the spectrum of conditions that can result in SCC?
- Locally invasive malignant tumour of epidermal keratinocytes
- Actinic keratosis > Bowen’s disease (in situ SCC) > SCC
SQUAMOUS CELL CARCINOMA
What are some risk factors for SCC?
- Excessive UV light exposure + sun burn
- Actinic keratoses + Bowen’s disease
- Immunosuppression (renal transplant, HIV)
- Smoking
- Long-standing leg ulcers
SQUAMOUS CELL CARCINOMA
What is the clinical presentation of SCC?
- Irregular, ill-defined red nodules (scaly, keratotic + ulcerated)
- Sun-exposed areas = face, scalp, hands
SQUAMOUS CELL CARCINOMA
What is the management of SCC?
- <20mm diameter = surgical excision with 4mm margins
- > 20mm diameter = surgical excision with 6mm margins
- Mohs micrographic surgery = high-risk patients + cosmetically important sites
MALIGNANT MELANOMA
What is a malignant melanoma?
Where do they commonly metastasise to?
- Neoplastic transformation of melanocytes
- Lungs + brain
MALIGNANT MELANOMA
What are the 4 types of malignant melanoma?
- Superficial spreading #1
- Nodular
- Lentigo maligna
- Acral lentiginous
MALIGNANT MELANOMA
What are the unique features of…
i) superficial spreading melanoma?
ii) nodular melanoma?
iii) lentigo maligna melanoma?
iv) acral lentiginous melanoma?
i) Pre-existing naevus which grows horizontal > vertical
ii) New lesion, aggressive, bleeds + ulcerates
iii) Sun damaged skin in elderly
iv) Subungual pigmentation (Hutchinson’s sign), non-whites
MALIGNANT MELANOMA
What are some risk factors for malignant melanoma?
- UV light exposure + tanning beds
- Fair skin + red hair
- Large number of moles
- FHx + increasing age
MALIGNANT MELANOMA
What is the clinical presentation of malignant melanoma?
ABCDE
- Asymmetrical
- Border irregular
- Colour irregular
- Diameter >6mm
- Evolving in nature
MALIGNANT MELANOMA
What would you do in suspected melanoma?
What is the single most important prognostic marker?
- Urgent 2ww derm referral
- Breslow thickness > thicker = worse prognosis
MALIGNANT MELANOMA
What is the management of confirmed melanoma?
- Excision biopsy > stage 0 = 0.5cm, stage 1 = 1cm, stage 2 = 2cm
- Stage III + IV metastatic = adjuvant immunotherapy, chemotherapy
BURNS
What are the various gradings of burns?
- Superficial epidermal (1º) = red, painful
- Superficial dermal (2º) = red, painful, blistered
- Deep dermal (2º) = decreased sensation, white
- Full thickness (3º) = white, no pain/blisters, may have muscle or bone involvement
BURNS
How can you assess the extend of the burn on the total body surface area?
What is the most accurate method?
- Wallace’s rule of nines
- Lung and broder chart
BURNS
What is Wallace’s rule of nines?
- Head + neck = 9%
- Each arm = 9%
- Anterior leg = 9% each
- Posterior leg = 9% each
- Anterior/posterior chest = 9% each
- Anterior/posterior abdomen = 9% each
- Groin = 1%
BURNS
What are some potential complications following burns?
- Hypovolaemic shock due to excess fluid loss in skin
- Infection due to loss of skin barrier
- Metabolic disturbance = high K+, high myoglobin (AKI)
BURNS
What are some indications to refer burns to secondary care?
- Any burn affecting face, neck, hands, feet or genitals
- Deep dermal + full-thickness burns
- Superficial dermal burns >3% TBSA adults, >2% paeds
- Any smoking inhalation injury, chemical or electrical burns or NAI
BURNS
What is your immediate management of burns?
What are you particularly looking out for?
- ABCDE (soot + stridor)
- IV fluids as per Parkland formula
- Analgesia
- Catheter
BURNS
What is the Parkland formula?
When is it indicated?
How is it applied?
- 24h fluid requirement (ml) = TBSA % x kg x 4
- Adults >15% TBSA or paeds >10% TBSA
- HALF given in FIRST 8H, remainder over 16h
BURNS
What is the management of burns post-ABCDE assessment?
- Stop burning via irrigation with water (>10m)
- Layered clingfilm NOT wrapped due to swelling + compartment syndrome
- Cover in sterile, non-adherent dressing
- Circumferential = escharotomy
- Full thickness = skin grafting
ULCERS
What is the cause of…
i) venous ulcers?
ii) arterial ulcers?
iii) neuropathic ulcers?
i) Venous insufficiency
ii) CVD risk factors (smoking, cholesterol, DM, HTN)
iii) Peripheral neuropathy #1 diabetes, unable to feel pressure to skin > ulcer
ULCERS
What is the location of…
i) venous ulcers?
ii) arterial ulcers?
iii) neuropathic ulcers?
i) Medial malleolus
ii) Forefoot + toes, incl. pressure sites
iii) Pressure points (e.g., plantar surface)
ULCERS
What are unique features of…
i) venous ulcers?
ii) arterial ulcers?
iii) neuropathic ulcers?
i) Varicose veins, haemosiderin deposits (pigmentation), lipodermatosclerosis (hard, tight skin), venous eczema)
ii) Punched out ulcers
iii) Reduced sensation in foot
ULCERS
Venous ulcers: comment on the following features…
i) regularity
ii) depth
iii) temperature
iv) pulses
v) sensation
i) Irregular
ii) Shallow
iii) Normal
iv) Present
v) Painless
ULCERS
Arterial ulcers: comment on the following features…
i) regularity
ii) depth
iii) temperature
iv) pulses
v) sensation
i) Regular
ii) Deep
iii) Cold
iv) Absent
v) Painful
ULCERS
Neuropathic ulcers: comment on the following features…
i) regularity
ii) depth
iii) temperature
iv) pulses
v) sensation
i) Regular
ii) Deep
iii) Normal
iv) Present
v) Painless + reduced sensation overall