Dermatology Flashcards
Tx of acute flare of eczema
Emollients
+ Topical corticosteroids
+/- Antihistamine
Antibiotics (topical or oral)
Steroid ladder
Hoon Eats Big Donuts
- Hydrocortisone
- Eumovate
- Betnovate
- Dermovate
Tx of chronic eczema
(1) Emollients + Topical corticosteroids
+/- Topical calcineurin inhibitor (Tacrolimus)
+/- Topical NSAID (crisaborole)
(2) UV light therapy +/- Topical coal tar
(3) Systemic immunosupressant (Ciclosporin, Methotrexate)
Ix for contact dermatitis
Patch testing
Scaly eruption on scalp
Red
Itchy
White flakes
+/- Bleeding
Diagnosis? Treatment?
Seborrhoeic dermatitis
(In infants ==> Cradle cap)
(In adults ==> Dandruff)
(1) Emollient
+/- Topical shampoo (contains ketoconazole, selenium sulphide..etc)
(2) Topical corticosteroids
(3) Oral antifungals
Psoriatic nail changes
POSH
Pitting
Onycholysis
Subungual hyperkeratosis
Salmon pink, silvery scales
On extensor surfaces
Auspitz sign (removal of scales –> bleeding)
Diagnosis?
Plaque psoriasis
Preceding strep throat infection
Tear drop scaly, papule
Diagnosis?
Guttate psoriasis
Conjunctivitis
Urthritis
Arthritis
Hyperkeratotic plaques on soles of feet
Diagnosis?
Keraderma blenorrhagicum
(Reactive arthritis)
Dry, red skin all over body
Fine scales
Recent drug or infection
Diagnosis?
Erythrodermic psoriasis
Tx of Psoriasis
PECS DDD (Topical Steroids + Vitamin D for acute flare)
Phototherapy
Emollients
Coal tar
Topical steroids (hydrocortisone, eumovate, betnovate, dermovate)
Topical Vitamin D
Dithranol (inhibits DNA synthesis)
DMARDs (Methotrexate, Ciclosporin)
Biologics - infliximab (anti-TNFa)
Types of Psoriatic arthritis
MASAP
- Monoarthritis of DIPJ (similar to OA)
- Asymmetrical polyarthritis - most common type
- Symmetrical polyarthrtitis (simmilar to RhA)
- Arthritis mutilans - destructive
- Psoriatic spondylitis (similar to Ank Spond)
Pearly papule
Nodule
Rolled borders
Telangiectasia
Ulcerated centre
Diagnosis?
Basal cell carcinoma
(Nodular BCC is the most common type)
Ix and Tx for BCC
Ix: Skin biopsy
Tx: Moh’s surgery
+/- Curettage
+/- Cryotherapy
+/- Radiotherapy
Rarely metastasise (<1%)
Progression to SCC
Actinic keratosis –> Bowen’s disease –> SCC
Growing tumour
Bleeding
Itchy
Keratin horn
Ulcerated
Diagnosis?
Squamous cell carcinoma
Types of SCC
Keratoacanthoma = keratin filled centre, rarely mets
Verrucous carcinoma = verrucous nodule, rarely mets
Marjolin’s ulcer = agressive ulcerating SCC, 40% mets
Tx of SCC
Surgical excision or Moh’s surgery
+/- Radiotherapy
+/- Chemotherapy
Itchy, red macule
Overlying crust
On sun-exposed area
Diagnosis? Treatment?
Actinic keratosis
May progress to SCC
Medical ==> Topical creams
- Diclofenac gel (3%)
- 5-Fluorouracil cream (5%)
- Imiquimoid cream (5%)
Surgical
- Surgical excision and curettage
- Cryotherapy
Itchy, red macule
Overlying crust
Sun-exposed limb
Biopsy shows full-thickness dysplasia
(i.e. carcinoma in situ)
Diagnosis? Treatment?
Bowen’s disease (= SCC in situ)
Tx same as for Actinic keratosis
Medical ==> Topical creams
- Diclofenac gel (3%)
- 5-Fluorouracil cream (5%)
- Imiquimoid cream (5%)
Surgical
- Surgical excision and curettage
- Cryotherapy
Types of Melanoma
Superficial spreading MM - most common
Nodular MM - most aggressive, lump
Lentigo maligna - usually on face
Acral - usually on palms and soles and nails
Sx of Melanoma
ABCDE + FLAWS
Asymmetry
Borders (irregular)
Colours (multiple)
Diameter > 6mm
Evolving
Staging of melanoma
Breslow thickness
(depth –> affects excision margins)
Define Keratoacanthoma
benign epithelial tumour.
well differentiated SCC that arise from the hair follicle
volcano or crater
centrally-filled with keratin
Define Dermatofibroma
Solitary dermal nodules
Free moving, firm
Dimple forms when pinched
“Stuck on appearance”
Flat or Raised lesion
Variable colour (flesh to light brown)
Diagnosis? Treatment?
Seborrhoeic keratoses
Treatment: None required or Excision
Round soft cutaneous mass
Mobile
Superficial
Painless
Diagnosis? Treatment?
Lipoma
Treatment: Observation (low malignant potential) or Excision
Types of Erythema multiforme
Minor EM = no mucosal involvement AND < 10% body surface area affected
Major EM = mucosal involvement AND < 10% body surface area affected
Causes of EM
Infection (HSV-1) = most common
Drugs (SNAP = sulphonamides, NSAIDs, allopurinolol, penicillin)
Characteristic finding in Erythema multiforme?
Treatment?
Target lesions (3 zones)
Treatment: Observation
+/- Emollient
+/- Corticosteroids
Define
Erythema multiforme
Steven-Johnson syndrome
Toxic epidermal necrolysis
Erythema multiforme = 1 mucosa surface + < 10% BSA
SJS = 2 mucosa surfaces + < 10% BSA
SJS-TEN = 10-30% BSA
TEN = > 30% BSA
BSA = body surface area
Causes of SJS / TENS
Drugs (AEDs = most common, Antibiotics)
Infection (mycoplasma pneumonia - rare)
Pathogenesis and Tx of SJS/TENS
Drug hypersensitivity reaction
Separation of skin at epidermal-dermal junction
(Nikolsky sign +ve)
Treatment
- Stop causative drug
- IV Fluids
- IVIG
Causes of erythema nodosum
Infection
- TB
- Streptococcal infection
Inflammation
- IBD
- Sarcoidosis
- Behcet’s disease
Malignancy
- Lymphoma
Drugs (COCP, Aspirin, Sulphonamides)
Tx of Acne
(1) Gentle facial cleanser
(1) Single topical therapy
- BAR
- Topical Benzoyl peroxide
- or Topical ABx
- or Topical retinoid
(2) Dual topical therapy
(3) Oral Antibiotoics (Doxycycline)
(4) Oral retinoid (isotretinoin / Roaccutane)
Itchy, erythematous papules and vesicles
On elbows, buttocks and lower back
Gluten-free diet
Dermatitis herptiformis
Single salmon pink plaque appears first (Herald patch)
Then, Christmas tree distribution
Diagnosis? Treatment?
Pityriasis rosea
HHV6/7 infection
Tx: Observation (self-limiting)
+/- Anti-virals
N.B. DDx from Psoriasis (which would be silvery)
Bullous pemphigoid
Autoimmune disorder against basement membrane
–> affects dermoepidermal junction
Tense bullae - found Deep (bullous pemphigoiD)
PemphiguS valgaris
Autoimmune IgG against desmosomes –> acantholysis
Acantholysis/Separation between layers of epidermis
Flaccid blisters with red surface underneath
Bullae are Superficial (pemphiguS valgaris)
Nikolsky’s sign +ve (pressure causes separation between epidermis and dermis)
Pemphigus foliaceus
Autoimmune IgG against desmosomes in upper epidermis –> acantholysis
Very thin bullae, no intact bullae
Criteria for hereditary haemorrhagic telangiectasia
inheritance?
Requires 3 out of 4
Epistaxis (nosebleeds)
Teleangiectasia (lips, mouth, fingers)
Visercal AV-malformations
FHx
Autosomal dominant
Scarring alopecia
Kerion (boggy mass)
Green fluoresence under Wood’s lamp
Tinea capitis
Circular, red lesion
Well defined border
Tinea corporis / Ringworm
Itchy, peeling skin between toes
Tinea pedis / Athletes foot
Itchy, hypopigmented patches
Mainly on trunk
Yellow-green fluoresence on Wood lamp
Diagnosis? Cause?
Pityriasis versicolour
Caused by Malassezia furfur
T: Topical anti-fungal
