ACNE
FACTS
Most aged 12-25
9 in 10 teenagers affected
3 in 10 need Rx to prevent scarring
Sites – face / back / neck / chest
Severity – mild – severe
Usually lasts 4-5y
HOW ACNE DEVELOPS
Sebaceous glands lie under skin surface
Make oil (sebum)
Sebum keeps skin supple and smooth
Pores allow sebum on to skin surface
Hairs grow through pores also
As a teenager more sebum is made
Hormones stimulate the sebaceous glands
More sebum – greasier skin
WHAT HAPPENS IN MILD TO MODERATE ACNE
Skin at top of pores thickens
Dead skin cells shed into pores
Pores become blocked
Blocking ‘plugs’ called comedones (white / blackheads)
Black colour due to skin pigment
Collection of sebum underneath causes papules (pimples)
WHAT HAPPENS IN MODERATE TO SEVERE ACNE
P. acnes accumulates in the pores
Immune system reacts causing inflammation
Surrounding skin reddens
Spots enlarge and fill with pus (pustules)
Pustules may enlarge forming nodules & cysts
Many heal fine
Some cause post-inflammatory hyperpigmentation lasting months
Small pitted scar sometimes left at site of spot
RARER CAUSES
Polycystic ovaries
Halogenated hydrocarbons
WHAT MAKES ACNE WORSE?
POP
Hormone changes around the period in women
Thick or greasy makeup (Consider non-comedogenic or oil free products)
Do not pick or squeeze
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Sweating heavily
Humid conditions
Tight clothing
Certain drugs – phenytoin, steroids, anabolic steroids
COMMON MYTHS
Not caused by poor hygiene – excessive washing may worsen it
Diet has little or no effect
Stress has no effect
It is not contagious
Cannot be cured by drinking lots of water
No evidence to say sunbathing /sunbeds help
GENERAL SKIN CARE
Wash with normal frequency ie twice daily
Mild soap and lukewarm water
Do not use abrasive soaps, astringents or exfoliating agents
Use soft wash cloth and fingers
Antiseptic washes unlikely to make any difference
Some topical Rxs dry the skin – use fragrance free water based moisturiser
AIMS OF TREATMENT
Clear spots as much as possible
Prevent scarring
TREATMENT OPTIONS
Do nothing
Topical preparations
Antibiotics
Hormone treatments
Isotretinoin
TOPICAL PREPARATIONS
Mild to moderate acne
May be needed for several months
Benzoyl peroxide (Panoxyl wash, aquagel, gel, cream)
Kills bacteria / Reduces inflammation / Unplugs blocked pores
Clears inflamed spots and helps clear blackheads and whiteheads
2.5, 4, 5 and 10% preparations
Wash skin 20-30mins before using
May bleach hair, bedding or clothing
Causes mild skin irritation commonly
Start with lowest strength
Use a water based preparation
Apply OD initially
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Wash off after several hours
Gradually increase length of time left on skin
Aim for BD when used to it
Retinoids
Unplug blocked pores / Some effect on reducing inflammation
Types include :
Adapalene (Differin cream or gel )
Tretanoin (Retin-A gel)
Isotretinoin (Isotrex gel)
Often used early to help unblock pores, treat comedones and mildly inflamed spots
When using may develop skin redness and peeling – settles with time
Spots often get worse before improving
Skin may be more sensitive to sunlight – apply at night and wash off morning
Causes burning, irritation and dryness
Patient should not be pregnant or planning to be so
Azelaic acid (Finacea gel, Skinoren cream)
Unplugs blocked pores & therefore good at clearing comedones
Some effect on reducing inflamed acne but not as good as benzoyl peroxide or
antibiotics
Less skin irritation than benzoyl peroxide
Topical antibiotics (Dalacin-T, Zineryt)
Reduce bacteria / Reduce inflammation
Little effect on unplugging blocked pores
Usually good with inflamed acne but blackheads and whiteheads remain
May cause mild irritation
General less side effects that other topical preparations
Combinations
Benzoyl peroxide + antimicrobial (Duac gel)
Tretinoin + antibacterial (Aknemycin plus)
Isotretinoin + antibacterial (Isotrexin)
ANTIBIOTIC TABLETS
Kill bacteria
Direct effect of reducing inflammation
Clear inflamed acne spots and any surrounding skin inflammation
Little effect on unplugging pores
If there are comedones better to use topical Rxs
If comedones and inflammation consider antibiotics and topical Rxs together
Tetracycline based antibiotics (Lymecycline)
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Do not give to children under 12
Do not take if pregnant, breastfeeding or intending to be so
Food and milk affects the absorption of oxytetracycline and tetracycline
Doxycycline and minocycline can be taken with food
If taking the pill use extra precautions during the 1 st 3 weeks of Rx
Other antibiotics (Erythromycin, Trimethoprim)
HORMONE TREATMENTS
COCP may help is acne partly related to hormone changes
Oestrogen part of pill thought to help
Dianette useful where a sensitivity to androgen hormone thought to occur
ISOTRETINOIN TABLETS
Reduces sebum production
Specialist only due to risk of serious side effects
HOW LONG FOR TREATMENT TO BE USED
4 weeks for any noticeable improvement
Often good response by 6 weeks
Sometimes maximum response in 4 months
After 6 weeks consider adding another Rx or changing to stronger Rx
WHAT TO DO AFTER STOPPING Rx
Often acne flares if Rx stopped
Maintenance Rx often needed for 4-5 years
Usually use benzoyl peroxide or topical retinoid
Long term ABs causes resistance so don’t use
Azelaic acid licensed for 6 months only
REFERENCES
Patient.co.uk
Acne vulgaris, Clinical Knowledge Summaries (June 2009)
Purdy S, de Berker D ; Acne. BMJ. 2006 Nov 4 ; 333(7575) : 949-53
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