Derm Flashcards
How many Fitzpatrick skin types?
1-6
Pattern of sun exposure for squamous cell carcinoma?
Chronic sun exposure
Precursors: Bowens/Actinic keratosis (Full/partial thickness keratotic dysplasia)
Pattern of sun exposure for basal cell carcinoma?
Intermittent damage ?
Treatment options for actinic keratosis?
Solase: topical diclofenac first line
Also, more potent: efudix (5-fluoracil) and imiquimod cream
Variant of SCC?
Keratoacanthoma - treat as such
What is a dermatofibroma?
Hard lump, typically history of trauma, typically insect bite
Types of bullae?
Unilocular or multilocular
Common cause of pustules?
Unilocular/multilocular
Keloid scar?
Grows outwith original scar area
Alopecia in kids?
Often an easily treated fungal hair infection
Severe bacterial infection secondary to fungal?
Often fungal infection from animals
Function of mast cells?
Histamine release
Function of fibroblasts?
Collagen production
Langerhans cell
Antigen presentation
Melanocyte
Protection from UV radiation
Keratinocyte
Vitamin D synthesis
Typical description of lichen planus?
Flat topped, violaceous papules
Symmetrical - flexor surfaces of wrists and ankles
Wickhams striae: fine white networks, also in buccal mucosa
Itchy
Scalp involvement: skin atrophy and scarring alopecia.
Is lichen Plans associated with atopy?
No
What is the Koebner phenomenon?
Linear eruption of lesions form itching/scratching.
Treatment of lichen planus?
Topical steroids, PUVA, UVB and post-inflammatory hyperpigmentation.
Layers of epidermis?
Keratin Granular Prickle cell Basal Dermo-epidermal junction
What is necrobiosis lipoidica
Associated with diabetes mellitus
Recognised manifestations of endogenous dermatitis?
Nodular prurigo
Discoid eczema
Pompholyx
Mycosis fungoides?
Form of cutaneous T cell lymphoma
Where is adrenaline contra-indicated?
Fingers, toes and penis
Areas supplied by end arteries
Where is keloid scarring most common?
Shoulders, upper back and sternal area
Management of Basal Cell Papilloma
Cryotherapy
If unresponsive -> C+C
Management of autoimmune skin conditions? EG bullous disease
Immunofluoresence
Recurrent BCC or BCC in difficult anatomical sites?
Mohs Surgery
Management of Bowen’s on shin?
Diagnostic biopsy
Widespread, flaccid blisters?
Shear off and leave painful erosions
Intra-epidermal blistering
Pemphigus vulgaris
Pyogenic granuloma - what is it?
In response to trauma - typically on extremities.
Remove surgically to exclude amelanotic melanoma
Where is Bowen’s disease commonly seen?
Legs of older ladies
What kind of alopecia is alopecia areata?
Localised non-scarring with spontaneous regrowth of initially fine white downy hair by 9 months in majority of patients.
How to diagnose alopecia areata?
Exclamation mark hairs: short broken hairs seen at edge of enlarging bald areas
What is alopecia areata associated with?
Autoimmune thyroid disease, vitiligo and atopy.
Suspect fungal infection with alopecia areata? Management
Treat with Wood’s lamp
What might isotretinoin affect?
Liver function and lipid levels.
Does not affect glucose tolerance or thyroid function
Side effects of isotretinoin?
Dry skin, eyes and lips. Dry fingers.
Nosebleeds, muscle aches and increased sensitivity to sunlight.
Where is the bullous pemphigoid blistering?
sub-epidermal
Treatment for bullous pemphigoid?
Systemic steroids/immunosuppression
Natural history of bulls pemphigoid?
Spontaneously resolves in around 50% of patients
Conditions where oncholysis might be present?
Psoriasis, thyrotoxicosis, infection, trauma, raynauds.
Hypo/hyperthyroidism, reactive arthritis, porphyria cutanea tarda
Nail changes in psoriasis?
Pitting, oncholysis and subungual hyperkeratosis (symmetrical)
Common differential for oncholysis?
onychomycosis
Cause of cold sores?
Herpes simplex
Cold sores precipitants?
UV exposure (immunosuppressive), URTI, menstruation, stress etc
Chronic urticaria - hallmark from history?
‘Moves around’
Individual lesions resolve within 24 hours
Cut off for acute vs chronic urticaria?
6 weeks
Normal PUVA administration?
Psoralen taken 2 hours before (orally) or applied immediately (topically)
Twice weekly treatments
Wear photo protective glasses for 2 hours after psoralen due to cataract risk
Contraindications to PUVA?
Methotrexate/cyclosporin -> increased carcinogen risk
Common side effect of psoralens?
Nausea
Is compression bandaging safe if ABPI is more than 1.4
No
May indicate calcification.
Do retinoids require LFTs etc done before treatment?
Yes
Typical response time to systemic antibiotics in acne?
6-8 weeks
Roacutane and scarring
Not great
Mechanism of action re: dianette in acne?
Reduces sebum production via anti-androgen effects
Commonest skin tumour
Basal cell carcinoma
Variants of BCC?
Nodular, pigmented, morphealike and superficial
‘stuck-on’ well defined border and warty?
Sebborheic wart
Manifestations of endogenous dermatitis?
Nodular prurigo
Pompholyx
Discoid eczema
What is mycosis fungoides?
Form of cutaneous T cell lymphoma
Most common drug eruption?
exanthematous or morbiliform eruption
Impetigo causative organism?
Staph aureus/beta-haemolytic strep
Typical precipitant of guttate psoriasis?
Strep throat infection
Differential of guttate psoriasis?
Pityriasis rosacea
IMF of cutaneous discoid lupus erythematosus?
Immunofluorescene: presence of autoantibodies
ABPI for full compression
0.8 or above
Non-sedating antihistamines only useful for itch in which conditions?
Insect bite
Urticaria
Herald patch?
Single patch preceding pityriasis rosea
Allergy to thiuram?
Rubber accelerator products
Most appropriate initial treatment of plaque psoriasis?
Vit D analogue
Do atypical naevi have more malignant potential?
Yes and extends to normal skin
Max isotretinoin dose with PUVA?
Around 20mg
