Terms
Define atopy
A familial tendency to manifest conditions - asthma, allergic rhinitis, eczema in which type 1 (IgE) hypersensitivity reactions are mediated after exposure to common environmental allergens.
What are the 3 types of skin cancer?
Basal Cell Carcinoma (BCC)
Squamous Cell Carcinoma (SCC)
Melanoma
- ordered from best to worst prognosis
What % of the body is represented by the anterior torso? (in regards to assessing the extent of a burn)
18%
What are 4 ways of assessing a skin lesion?
SCAM: size, size, shape; colour; associated secondary change eg. excoriations, inflammation; margin and morphology
What is the difference between allergy and hypersensitivity?
Allergy: dysregulated immune response to substance in the environment that are harmless to most people. Leads to hypersensitivity.
Hypersensitivity: exaggerated undesirable reaction by a dysregulated, but otherwise normal, immune system. Must have already been exposed to this substance.
What layer(s) of skin are nodules typically found?
Dermis (also often subcutaneous tissue)
What are 5 common categories of allergens?
Food allergens (nuts, dairy, eggs etc.), pollen, animal dander, grass mix, dust mites
What is required in a history when screening for allergy?
1) Personal history of allergy 2) Relation of environmental exposures and symptoms 3) Family history 4) Medications 5) Past medical history 6) Social and work history - include exposures to toxins, smoking etc.
Define a spongiotic inflammatory skin condition
Intercellular oedema - widening of gaps between cells and intercellular prickles
What are considerations you must keep in mind when prescribing corticosteroids to treat atopic dermatitis?
patient education - applying sparingly short term
tolerance
skin thinning (topical)
stunted growth (oral)
What is the dosage for giving lignocaine + adrenaline as local anaesthetic in an adult?
7mg/kg
What is the depth of this burn: dark pink, blistered, capillary refill: 5 seconds, no sensation, scarring
Mid dermal
What type of inflammatory skin condition is lichen planus and what are its characteristic features?
Lichenoid. PPP - purple polygonal papules.
Lymphocytic destructive attack on the epidermal basal layer.
What are the 5 functions of the skin?
1) Temperature regulation 2) Protection from infection 3) Regulation of water 4) Vitamin D synthesis 5) Antigen presentation and immune and innate immunological function
Describe the blood supply of the skin and how this relates to homeostatic thermoregulation
Increased temperature = anastomoses dilate = blood flow through skin in capillary beds and venous plexus = heat transfer/dissipation.
Decreased temperature = anastomoses close off = less blood flow = retain heat.
What is the difference between a macule, nodule and a papule?
Macule: flat, non-palpable circumscribed alteration of skin colour < 1cm. Nodule: circumscribed raised / palpable mass, greater than 1 cm diameter. Papule: circumscribed raised/ palpable elevation, less than 1 cm diameter.