Dermatology: Skin Infections Flashcards
What are the 3 layers of the skin from top to bottom
epidermis
dermis
hypodermis
What is the function of the skin?
Provides an anatomical barrier
Main method of Heat Regulation
Sensory input from the body
Storage for lipids and water
Drug absorption
waste excretion
What is commensal flora
- normal colonisation that inhabits pathogens in healthy hosts
- mainly bacteria and fungi (staphylocci and candida)
What is oily skin?
- more secretion from sebaceous glands (sebum)
- more bacterial colonisation
- skin becomes heavier and thicker
- more risk of pore blockage = more spots and pimples
- less likely to wrinkle and age
What are comedones?
- blackheads
- feature of acne vulgaris
- build up of keratin and sebum
- block pores and oxidise giving ‘black’ appearance
give 4 examples of bacterial infections of the skin
- furuncles and carbuncles
- acne
- erysipelas
- impetigo
What is furuncles
infection of the skin- pockets with pus
- caused by staphylococcus aureus
- red, painful and swollen
- drain pus- antibiotics not always necessary
what are carbuncles
furuncles grouped together
what is folliculitis
furuncle in a hair follicle
Acne is a term used for lesions arising from…
- comedones
- papules
- pustules
- nodules
- inflammatory cysts
What age does acne usually affect ?
13-18
- 80% of teenagers
25-40
- 5% women and 1% men continue to be troubled
What are some causes of acne?
- follicular sensitivity to testosterone (increase during puberty)
- propionibacterium acnes overgrows and leads to infection and cysts
- scars can form if cysts rupture
What can acne be made worse by?
- some contraceptive pills (progestogen)
- greasy skin cleansers
- systemic steroid treatment
- some anticonvulsant drugs
SQUEEZING the spots
How can acne be managed locally?
- reduce excess skin oil (cleaners- gentle soap)
- antibacterial agents
benzoyl peroxide
retinoids
antibiotic lotions
How can acne be treated if local treatments fail?
- antibiotics (tetracycline based) minocyclin
- retinoids - isotretinoin
- hormone manipulation (anti-androgens) cyproterone
What causes erysipelas?
streptoccus pyogenes
Describe how erysipelas may present?
defined sharp raised border
may blister and peel
usually systemic symptoms (fever and rigors)
How is erysipelas managed?
systemic antibiotics
- oral or sometimes IV
What can erysipelas sometimes progress to>
necrotising fasciitis
septic shock
What is impetigo? (causes, appearance, treatment ?)
- highly infectious skin disease
- staphylococcal or streptococcal
- crusty red blister appearance (often associated with eczema)
- treatment with topical antibiotics