Dermatology Flashcards
How is UV involved in carcinogenesis?
UVB = causes direct DNA damage UVA = produces oxidative damage
p53 mutation is associated with what (3)
Actinic keratoses
Carcinoma in situ (Bowens)
SCC
SSC is associated with (2)
Precursor lesions
Transplant patients
What virus is SSC associated with?
HPV
What virus is Kaposi’s sarcoma associated with?
HHV 8
Types of BCC
Nodular
Superficial
Infiltrative
Common appearances of BCC
Raised, pearly edge
Telangiectasia
Central ulceration
What is Moh’s surgery?
Excision and examination with pathology then going back in for revision surgery
Often used when margins aren’t clear e.g. nasal lesions
Pathology of actinic keratoses
Dysplastic keratinocytes
Pathology of Bowen’s disease
Common site
Full thickness dysplasia
Lower leg
Types of melanoma (4)
Superficial spreading
Lentigo maligna
Nodular
Acral lentiginous
Presentation of superficial spreading melanoma
Lower limbs
Associated with intermittent high UV
Presentation of lentigo maligna melanoma
Face
Associated with cumulative UV exposure
Presentation of nodular melanoma
Trunk
Associated with intermittent high UV
Presentation of acral lentiginous melanoma
Common on the palms, soles and nails
Growth phase - which type of melanoma STARTS with a vertical growth phase?
Nodular
Breslow thickness =
Measures the deepest tumour cell from the granular dermis
Sturge Weber Syndrome is associated with
Port Wine Stains
= usually seen in the CN V1 distribution, stain associated with ipsilateral vascular malformation
Presentation of Strawberry Naevus
= benign soft tissue tumour
Usually a single lesion presenting in the first month of life, often the head and the neck
Complications: peri-ocular lesions can affect vision, large tumours can cause airway obstruction
What can a strawberry naevus indicate?
Underlying defect e.g. spina bifida
Cafe au lait macules (CALMs) are associated with…
Neurofibromatosis Type I
Skin features in neurofibromatosis type I (3)
CALMs
Neurofibromas
Axillary/inguinal freckling
Ash leaf macules are associated with…
Tuberous sclerosis
Skin and nail features in tuberous sclerosis (4)
CALMs
Facial angiofibromas
Periungal fibromas
Shagreen patch
Histological findings in Psoriasis
Thickened parakeratotic corneal layer
Munro microabscesses
Abscence of granular layer
Auspitz’s sign =
removing scale reveals pin point bleeding
Presentation of guttate psoriasis
Associated with streptococcal sore throat
See multiple small lesions on the trunk
Presentation of erythrodermic psoriasis
Management
> 90% of the skin surface is red, usually occurs in patients with known or deteriorating psoriasis
Mx: need fluid balance, rest, emollients and systemic immunosuppressants
Example of Vitamin D analogue
Calcipotriol e.g. dovobet
Pathogenesis of Acne (4)
Increased sebum production
Poral occlusion
Dermal inflammation
Bacterial colonisation (p. acnes)
Management of Acne Vulgaris
- Topical treatments
- Oral AB e.g. doxycycline or erythromycin
- Isotretinoin
Can try OCP in women
Management of Acne Rosacea
Avoidance of dietary triggers
Topical metronidazole
May consider oral antibiotics
Presentation of atopic eczema
Infants VS Children
Infancy - extensor surfaces, face, nappy region often spared
Children - flexor pattern
Example of a mild steroid
Hydrocortisone 1%
Example of moderate steroid
Clobetasone butyrate 0.5%
Example of potent steroid
Betamethasone valerate 0.1%
Example of very potent steroid
Clobetasol proprionate 0.05%
Other topical steroid sparing agents used in eczema
Calcineurin inhibitor
e.g. Tacrolimus
Management of eczema herpeticum
Oral aciclovir
Urgent referral
Causes of acanthosis nigricans
Diabetes/insulin resistance
Obesity
GI/GU cancer
Mycosis fungoides =
Cutaneous T-cell lymphoma
Starts as a patch, if progresses can become a plaque and then an overt tumour
Associations with erythema nodosum (5)
URTI/streptococcus Oral contraceptive pill Inflammatory bowel disease Sarcoidosis Penicillins
Management of seborrheic dermatitis
Ketoconazole 2% cream
+/- mild topical steroid
Variable pigmentation differential
Vitiligo
Pityriasis versicolour
Management of itch in CKD
UVB can be useful
Presentation of polymorphic light eruption
= itchy spotty rash brought on by the sun
Settles when out of the sun
ABPI indicating vascular disease
<0.8
ABPI indicating calcification
> 1.3
Management of Bowen’s disease
5-FU topical
Investigation of choice for dermatitis herpetiformis
Diagnostic biopsy with immunofluorescence
Presentation of pityriasis rosea
Associated with viral infection
Often starts as a larger ‘herald’ lesion which then fades before smaller more widespread lesions appear on the trunk
Management of lichen planus
Emollient
Strong steroid
Complication of impetigo
Blistering producing bullous impetigo
Can result in staphylococcus scalded skin syndrome
Management of impetigo (1st line)
Topical fusidic acid
Management of neglected/difficult to excise BCC
Radiotherapy
What is a partial thickness loss of skin called?
Erosion
What is a full thickness loss of skin called?
Ulceration
What is a keratoacanthoma?
Appears like an SCC, developing very rapidly, but will almost completely resolve
Association with erythema multiforme (2)
Herpes simplex
Mycoplasma
Skin signs of lymphoma (2)
Erythroderma
Ichthyosis
Findings in bullous pemphigoid
Linear IgG and complement on the basement membrane
Pathogenesis in pemphigus vulgaris
Antibodies formed against desmoglein 3
Management of pemphigus vulgaris
Cyclophosphamide 500mg IV every 4 weeks
High dose dexamethasone
Findings in dermatitis herpetiformis
Granular deposits of dermal papillary IgA
Management of anaphylaxis
IM Adrenaline (1:1000)
High concentration O2
IV Anti-Histamine
200mg IV hydrocortisone
Where are melanocytes found?
Dermo-epidermal junction
Management of lentingo melanoma
Iquimod
Watchful waiting
Difference in location of salmon patches VS port wine stain
Salmon patches are usually central
Presentation of frontal fibrosing alopecia
Affects the front of the forehead, produces a shiny clear cut line
Sometimes get involvement of the eyebrows
What is ‘dress’?
What is it associated with?
Potential complications?
A drug related rash with eosinophilia
Associations = carbamazepine, lamotrigine, co-trimoxazole
Complications = liver necrosis, lymphadenopathy, pericardial effusion
Nikolsky’s Sign
= press on the blister and it will spread laterally
How is erythema multiforme classified?
Differences between?
Major and minor
Major is associated with mucosal involvement
Examples of sedating antihistamines (2)
Use of sedating anti-histamine
Chlorphenamine
Hydroxyzine
Useful for itch (non-sedating won’t have an effect)
Presentation of pyoderma gangrenosum
Seen as an initial red papule which becomes a necrotic ulcer
Can be associated with IBD or connective tissue disease
Pityriasis versicolour
- Cause
- Worsened by…
= fungal
Made worse by the sun
Pyoderma gangrenosum
- Presentation
- Association
= starts as a red papule > open ulceration
Association: rheumatoid arthritis, ulcerative colitis, vasculitis
Management of rosacea
ORAL antibiotics
Management of dermatitis herpetiformis
Dapsone
= antibiotic