Background Flashcards
history
occupation important
HPC: duration, location, initial appearance, evolution, associated symptoms (itch, pain, bleeding), treatments tried
RF: age, sunburn, occupation, smoking, travel
impact/ICE: psychosocial important
examination
DCM: rashes/eruptions
ABCDE; 5S: site, size/shape, symmetry, surface. surrounding
‘SCAM’: size/shape, colour, associated change, morphology/margin
palpate: surface, consistency, mobility, tenderness, temp , illumination, LN
check hair, nails, oral mucosa
skin anatomy
epidermis:
- corneum: horny cells; keratin
- lucidum: thick skin only; pale compact keratin
- granulosum: keratohyaline granules and lipids; looser
- spinosum: ‘prickle cells’; differentiation
- basale: dividing cells
dermis: papillary and reticular; appendages, nerves, elastin/collagen, BV
subcutis: fatty CT
keratinocytes, Langerhan’s (APC), melanocytes, Merkel’s (nerve endings)
skin function
protection (Barrier) temperature sensation vitamin D synthesis immunosurveillance appearance/cosmesis
hair
modified keratin; shaft, bulb, and melanocytes
lanugo: fine; fetus/AN
vellus: fine short hair; all surfaces
terminal hair: course, long; scalp, eyebrows, eyelashes, pubic, pits, legs, face
anagen (grow), catagen (Regress), telogen (shed/rest)
nails
nail plate (keratin)
matrix
proximal nail fold
nail bed (Capillaries)
glands
sweat: SANS, temp reg; eccrine and apocrine (smelly, EAM, areola)
sebaceous: sebum from hair follicles; lubricate + waterproof; androgens
wound healing
haemostasis: constriction, platelets, fibrin clot
inflammation: dilatation, NP/MP migration, phagocytosis
proliferation: granulation (fibroblast), angiogenesis, re-epithelialisation (migration)
remodelling: collagen reorganisation, scar maturation
rash description
DCM
pigmented lesion
ABCDE + compare to other lesions
asymmetry border: smooth, reg, reg irreg, irreg colour: uniform, gradient/change, random diameter evolution and elevation
individual lesion
5S: site, size/shape, symmetry, surface, surroundings
SCAM: size/shape, colour, associated change, morphology/margin
erythema DDx
psoriasis: extensors, scaly, plaques drugs incl. EM/SJS/TEN eczema: excoriation, flexures mycosis: annular, scaly rim, central clearing pityriasis rosea: herald patch, scaly lymphoma: LN palpable idiopathic infection: erythrasma, candidiasis, cellulitis
purpura DDx
thrombocytopenic:
- meno septicaemia: acute, Sx, petechiae, bruise, hge, necrosis
- DIC: trauma/Ca/obstetric/liver, bleeding, pet/ecc, hge, necrosis
- ITP: ?HSM, well, preceding viral
nonTP:
- drugs
- vasculitis/CTD: systemic upset, dependent areas, palpable painful purpura
- aged skin: sun-damaged, non-palpable purpura, systemicall well
pruritus DDx
derm:
- coeliac: dermititis herpetiformis (pap/ves)
- eczema: dry, erythema, vesicles, exudate
- scabies: burrows and rubbery nodules
- lichen planus (purple + lacy white), lichen sclerosis (white thinning)
- urticaria: pink wheals; round/annular/polycyclic, triggers
- chicken pox: vesicles
non-derm:
- cholestatic jaundice
- drugs: aspirin, alcohol, morphine, codeine
- pregnancy
- uraemia
- DM/thyroid
- malignancy (e.g. blood Ca)
- iron deficiency, PRV
- xerosis
- psych
depigmentation DDx
vitiligo inflammatory depigmentaion DLE (lupus) pityriasis abla piebaldism Addison's (hyperpigment contrast) pityriasis versicolour
Koebner’s
psoriasis lichen planus viral warts molluscum contagiosum sarcoidosis
blisters DDx
impetigo insect bites HSV/HZV acute contact dermatitis pompholyx: tiny blisters burns bullous pemphigoid: hge tense blisters; IgG in hemidesmo/BM pemphigus vulgaris: superfical 'shedded' blisters; IgG desmosome (epidermis), Nikolsky sign (shedding)
red swollen leg DDx
cellulitis: painful, trauma/ulcer, diffuse edge, systemic upset
erysipelas: painful, spreading, trauma/ulcer, defined, systemic upset
DVT: painful, RFs, may be cyanotic, systemically well, tender
chronic venous insufficiency: heavy/ache, better with move; blue/purple, oedema, varicose veins, LDS, eczema, venoux ulcer
necrotising fasciitis: extremely painful, systemic upset, rapid spread
anaphylaxis
lip/tongue swelling bronchospasm hypotension angioedema urticaria: itchy wheals
Rx: adrenaline (0.5ml 1:1000), antiH (10-20mg), CST (100mg)
acne DDx
Rosacea: no comedones peri-oral dermatitis: no comedones folliculitis: no comedones DLE drug eruption endocrine: sudden, severe, hyperandro, menstrual
erythema multiforme DDx
infection: strep (Ag hypersensitivity
HZV (65% of cases)
drugs: penicillin, sulphonamides, phenytoin, allopurinol
urticaria: 2 colours (annular wheal),
