Acne Flashcards
What are the types of Acne? [2]
Types classified according to appearance [5]
Acne Vulgaris
Acne Rosacea
Appearance: Neonatal Acne excoriee Papulopustular Nodulocystic Comedonal
Epidemiology
Acne vulgaris [3]
Acne rosacea [3]
- Peak age of onset, gender predisposition, ethnic group
Acne Vulgaris peaks at 15-18yrs although many women have a delayed onset. M=F but M is more severe
Acne Rosacea peaks at 30-40yrs. F>M but M is more severe. Almost always fair skinned caucasians
Explain the pathogenesis of Acne Vulgaris? [3]
Abnormal keratinisation of the infundibulum
- The hair follicle duct becomes blocked as corneocytes of the hair follicle stick together
Increased sebum
-Sebum becomes more viscous and so harder to clear
Infection with P. acne
- Infection with Propionibacterium acne (P.acne). Bacterium leads to an inflammatory reaction and pustule formation
What bacteria is most responsible for inflammation in acne vulgaris? [1]
Propionobacterium acnes - anaerobe
Explain the formation of whiteheads, blackheads and papules/pustules/cysts/scars etc
White heads - Closed Comedones, aka the skin has closed over the comedone
Black head - Open comedone, aka the plug is so big the skin cant close and its visible. (Black because of melanin not dirt)
Papules/pustules/cysts/nodules - due to bacterial inflammation
Scars form after inflammation, especially if the spots are picked or popped
What are the main types of Acne scars? [3]
Atrophic scar- Common, indented, due to loss of collagen during healing
Hypertrophic scar - Uncommon, protruding, due to excess collagen from abnormal healing
Keloid scar - Rare, similar to hypertrophic but extend beyond the margins of the injury
Treatment of Acne Vulgaris
Topical:
Retinoids (Vit A derivatives)
Benzoyl Peroxide (BPO)
Anti-biotics
Non-topical:
- Anti-biotics
- Anti-androgens (OCP Dianette)
- Isotretinoin
- Light based therapies (not on NHS)
How do retinoids help acne vulgaris? [3]
Side effects [7]
Inhibiting sebum excretion (contrast with topical retinoids, which do not reduce sebum excretion).
It does this by causing a temporary atrophy of the sebaceous glands.
Following a 4 month course, generally sebum excretion does not return to pre-treatment levels for several years.
Highly teratogenic (2 methods of contraception
Skin and mucosal dryness
Depression
Hypercholesterolemia, hypertriglyceridemia
Deranged LFTs
Arthralgia, myalgia
How does Benzoyl Peroxide help acne vulgaris? [1]
Has an anti-inflammatory effect
What anti-biotics are used for Acne Vulgaris? [3]
Topically
- Erythromycin
- Tetracyclines, doxycycline
- Clindamycin
Oral
- Erythromycin if pregnant or <12y/o
- Tetracyclines
How do you prevent resistance to acne anti-biotics? [1]
Use somewhat sparingly and combine with BPO
What is dianette? [1]
A Combined Oestrogen & Progesterone pill with an anti-androgen added
Dosage of isoretinoin [2]
1mg/kg/day for 16 wks
Generally given in smaller doses to reduce dry skin side effects
Pros [3] and cons of isotretinoin [3]
- Best treatment available for stubborn/severe acne
- Permanently cures 60-70% of Acne Vulgaris Patients
- Easy to take (swallowed 1/day with a main meal)
Highly teratogenic (+1 month after stopping)
Expensive
Causes severe dry skin
Describe the pathogenesis of Acne Rosacea? [2]
What is the one clinical feature that differentiates it from vulgaris? [1]
Chronic relapsing remitting inflammation [1] of the PSU (Pilo-sebaceous unit) and cutaneous vasculature. [1]
Unlike Vulgaris, rosacea lacks comodones [1]
What are the subtypes of Rosacea? [4]
- Erythemato-telangectasic Rosacea
- Papulo-pustular Rosacea
- Phymatous rosacea (Big red swollen nose, mainly men)
- Ocular rosacea
Generally they overlap & they’re mostly treated the same
How does ocular rosacea occur? [3]
What is pre-rosacea [2]
Rosacea affects the meibomian glands in the eyelids [1], reducing tear film causing dry gritty eyes. [1] It eventually leads to sight loss if not treated. [1]
Pre-rosacea: flushing triggered by stress/blushing, alcohol and spices
Presentation of rosacea - clinical appearance? [2]
Central symmetrical facial rash with erythema, telangiectasia, papule and pustules
Facial lymphedema
Inflammatory nodules
Blepharitis, conjunctivitis
Quick list of rosacea treatments
Topical:
- Antibiotics
- Azeleic Acid
- Ivermectin
- Brimonidine
Non-topical:
- Anti-biotics
- Isotretinoin
- Light based therapies
- Laser therapy
What Anti-biotics are used for rosacea and why?
1st line: Metronidazole topically
2nd line: Tetracyclines systemically eg doxy
They’re used for their anti-inflammatory effect rather than anti-bacterial
How is isotretinoin different for rosacea?
Its used in smaller doses as rosacea patients already suffer from dry skin
It doesn’t cure it so needs to be kept on long-term
What subtypes of rosacea have special treatments?
Erythemato-telangectasic Rosacea is best treated with light therapies
How does azeleic acid work?
It kills acne bacteria and inhibits keratin production
How does Ivermectin work?
Kills parasitic mites which are believed to be part of the pathogenesis of acne rosacea
How does brimonidine work? [2]
Causes vasconstriction thus reducing the redness of rosacea.
Its used when someone has a night out or important event they want to minimise their rosacea for, not an everyday treatment
Describe treatment for ocular acne rosacea [3]
Eyelid hygiene, ocular lubricants +/- CICLOSPORIN
Describe treatment for: (dose, frequency)
Mild rosacea [2]
Moderate to severe [3]
- Mild: METRONIDAZOLE gel or cream BD for 3-4m or topical 15% AZELAIC acid
- Moderate or severe: oral TETRACYCLINE eg DOXYCYCLINE for 4m; ISORETINOIN or lasers rarely rqd
Indications for isoretinoin [2]
Failure to respond to topical treatments and oral antibiotics when given for > 6 months
Scarring acne
Re: antibiotic prescribing, when is it safe to say its not working?
Antibiotic prescribing in treatment of acne is generally long-term and patients can remain on antibiotics for years.
It is not possible to say that a drug is not working for acne unless the patient has been taking it for up to three months. Patients may need to be treated for several years or more.
Most common reason that antibiotics fail in treatment of acne
Antibiotic resistance to P.acne can cause failure of treatment
How do we decrease risk of resistance? [3]
Systemic antibiotic + Topical retinoid + Topical benzoyl peroxide
