Diagnosis Flashcards
What is dermoscopy?
skin surface microscopy - - only useful in experienced hands, computerised algorithms can also help diagnosis of MM.
What are Blaschko’s lines? Describe some conditions and why they present in this way?
- pathways of epidermal cell migration and proliferation
- often inherited but there are many causes:
- X dominant skin disorders (CHILD syndrome)
- pigment disorders (segmental vitiligo)
- acquired (linear lichen planus)
- V shaped on upper spine, S on abdomen, U from breast area.
What is a way to describe dermatological diagnoses?
- Distribution
- Configuration
- Colour
- Morphology
- Skin surface changes
- Secondary changes
List some terms used to describe the distribution of dermatological conditions.
- Blaschko’s lines
- Sporotrichoid
- innoculation or trauma related
- Dermatomal
- Extensor or flexor
- Flexural (intertriginous)
- follicular
- clustering, coalescing
- contact
- generalised
- herpetiform
- photosensitive
- pressure areas
- seborroeic (oiling and crusting from oversecretion of sebum)
- symmetrical
- truncal
- acral (toes and fingers)
- unilateral
List some ways to describe configuration of lesions, describe each.
- nummular (coin shaped) or discoid
- ring shaped
- e.g. DLE (SLE lupus erythematosus)
- linear lesion (not following dermatoma, Blaschkos)
- target lesion
- e.g. erythema multiforme
- gyrate lesion (coiled or twisted lesions)
- annular (central clearing with circular or ovoid appearacne) - ringed
- e.g. tinea corporis
List some ways to describe the colour of a lesion.
- hyperpigmentation/hypopigmentation
- depigmentation
- carotenaemia (e.g. xanthoderma)
- Jaundice
- erythema
- infarcts
- erythroderma
- telangiectasia
- purpura (petechia or ecchymoses)
List some terms to describe the morphological appearance of lesions.
- Flat, elevated,
- Consistency may be soft, firm, hard, fluctuant, sclerotic (board like)
- Macule - area <1.5cm smooth surface
- Patch large area of colour change with colour change
- Papule - small palpable lesion <0.5cm allow up to 1.5cm
- Pedunculated
- Sessile
- Umbilicated
- Filiform (thread like)
- Dome-shaped
- Verrucous (warty)
- Nodule (solid - enlargement of papule)
- Cyst - nodule or papule with fluid
- Plaque >1cm - elevated and thickened.
- Vesicle <0.5cm
- Pustule purulent vesicle
- Abscess - localised collection of pus
- Bulla - large fluid filled blister
- Weal - swelling in dermis (urticaria)
Describe some terms for skin surface, describe what they mean.
- Scaling or hyperkeratotic (thickening of stratum corneum)
- Psoriasiform (psoriasis looking)
- Pityriasiform (fine branny scales)
- Lichenoid (looks like lichen planus) - papulosquamous
- Keratoid (horn)
- Exfoliation
- Maceration (breakdown from prolonged moisture)
- Verrucous
Some terms to describe secondary changes to the skin
- lichenification
- crusting
- dystrophy
- excoriation
- erosion
- fissure
- fungating
- granulation tissue
- ulcer
- granuloma
- hypertrophy
- atrophy
- alopecia
- scar
- infiltration
Name some clinical signs and what they mean. What are they associated with?
- Darier sign - mastocytosis - wheal formation on rubbing lesions. (compression of mast cells in systemic mastocytosis)
- Auspitz sign - pinpoint haemorrhages under scale suggests psoriasis
- Nikolsky sign - dislodgement of epidermis by lateral finger pressure in acantholytic disorders such as pemphigus (vs pemphigoid)
What are some clinical tests that can be done to assist in dermatology?
- patch testing for allergic contact sensitisation (T4 reaction)
- photopatch testing
- Prick testing for T1 allergies
- acetowhitening to detect penile, vulvar, or anal warts using 5% acetic acid (white vinegar) - HPV identification
