Dermatology Flashcards
What age does acne vulgaris often affect?
People during puberty and adolescence.
Most people are affected at some point during their lives.
What is the cause of acne vulgaris?
- caused by chronic inflammation, with or without infection, in the pilosebaceous unit (pockets in the skin)
- pilosebaceous units are tiny dimples in the skin that contain hair follicles and sebaceous glands
- sebaceous glands produce sebum (natural skin oil, waxy)
- acne results from increased sebum production, trapping of keratin (dead skin cells) and blockage of the pilosebaceous unit.
What increases the production of sebum and what can be used to improve this?
Androgen hormones increase production of sebum so acne is exacerbated by puberty.
Anti-androgenic hormonal contraception improves this.
What are swollen and inflamed pilosebaceous units called?
Comedeones.
What bacteria is felt to play an important role in acne?
Propionibacterium acnes.
Thought that excessive growth of this bacteria can exacerbate acne.
Many acne treatments aim to reduce these bacteria.
How does acne vulgaris present?
- significant variation in severity
- red, inflamed and sore ‘spots’ on the skin
- typical distribution across the face, upper chest and upper back
What are comedones?
Skin coloured papules representing blocked pilosebaceous units.
What are blackheads?
Open comedones with black pigmentation in the centre.
What are ‘ice pick scars’?
Small indentations in the skin that remain after acne lesions heal.
What are hypertrophic scars?
Small lumps in the skin that remain after acne lesions heal.
What is the aim of treatment?
- reduce symptoms of acne
- reduce risk of scarring
- minimise psychosocial impact of the condition
What else must be explored alongside the acne symptoms?
- psychosocial burden
- potential anxiety and depression associated with condition
What is the management for acne vulgaris?
- no treatment if mild
- topical benzoyl peroxide
- topical retinoids
- topical abx e.g. clindamycin
- oral abx e.g. lymecycline
- OCP
How does topical benzoyl peroxide work?
- reduces inflammation
- unblocks skin
- toxic to P.acnes bacteria
How do topical retinoids work?
- chemicals related to vitamin A
- slow sebum production
What is the risk of retinoids?
- Highly teratogenic
- females of childbearing age require effective contraception
What must be prescribed alongside topical abx to reduce bacterial resistance?
Benzoyl peroxide
What is an effective last-line option?
- oral retinoids for severe acne e.g. isotretinoin (roaccutane)
- careful follow-up, monitoring, reliable contraception
How does oral isotretinoin work?
- reduces sebum production
- reduces inflammation
- reduces bacterial growth
- prescribed under expert supervision by dermatologist
How long before becoming pregnant must patients stop isotretinoin?
At least 1 month before becoming pregnant.
What are the side effects of isotretinoin?
- dry skin/lips
- photosensitivity of skin to sunlight
- depression, anxiety, aggression, suicidal ideation
- rarely Stevens-Johnson syndrome, toxic epidermal necrolysis
What must patients be screened for prior to starting isotretinoin?
- mental health issues
What is impetigo?
A superficial bacterial skin infection.
It occurs when bacteria enter via a break in the skin = may be in otherwise healthy skin or related to eczema or dermatitis.
What bacteria most commonly causes impetigo?
Staphylococcus aureus
What is characteristic of a Staphylococcus skin infection?
‘golden crust’
What bacteria less commonly causes impetigo?
Streptococcus pyogenes.
Is impetigo contagious?
Yes - children should be kept off school during the infection.
What can impetigo be classified as?
1) Non-bullous
2) Bullous
Where does non-bullous impetigo typically occur?
Around the nose or mouth.
What happens to the exudate in non-bullous impetigo?
Exudate from the lesions dries to form a ‘golden crust’.
They are often unsightly but do not usually cause systemic symptoms or make the person unwell.
What is the first-line treatment for localised non-bullous impetigo?
Hydrogen peroxide 1% antiseptic cream
What else can be used for non-bullous localised impetigo?
Topical abx:
- fusidic acid 2%
- mupirocin 2% (if fucidin acid resistant)
What can be used to treat more widespread or severe non-bullous impetigo?
Oral flucloxacillin
What general advice should be given about non-bullous impetigo?
- advice to avoid spreading the impetigo
- avoid touching or scratching the lesions
- hand hygiene
- avoid sharing face towels and cutlery
- children must be off school until all lesions have healed or have been treated with abx for at least 48 hours
