Acne Flashcards
What are the type sof Acne?
Acne Vulgaris
Acne Rosacea
Who is most effected by Vulgaris and rosacea?
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?
A disease of the Pilo-sebaceous unit:
1) Keratinocytes at the follicle top become sticky and aggregate instead of shedding forming a comedone (Plug)
2) Sebum becomes more viscous and so harder to clear
Sometimes commensal bacteria cause inflammation
What bacteria is most responsible for inflammation in acne vulgaris?
Propionobacterium acnes
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?
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
Qiuck list of the treatments for 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?
Vit A Derivatives applied topically can unstick comodones
Often combined with BPO
How does Benzoyl Peroxide help acne vulgaris?
Has an anti-inflammatory effect
Hence often combined with Retinoids anti-comodone effect
What anti-biotics are used for Acne Vulgaris?
Topically
- Erythromycin
- Tetracyclines
- Clindamycin
Non-topical:
- Erythromycin
- Tetracyclines
How do you prevent resistance to acne anti-biotics?
Use somewhat sparingly and combine with BPO
What is dianette?
A Combined Oestrogen & Progesterone pill with an anti-androgen added
Used for women with acne Vulgaris
What is isotretinoin?
Trade name Roaccutane
Its an expensive non-topical retinoid (Vit A derivative) prescribable only by specialists.
1mg/kg/day for 16 wks (generally given in smaller doses to reduce dry skin side effects)
Pros and cons of isotretinoin?
- 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?
Chronic inflammation of the PSU (Pilo-sebaceous unit) and cutaneous vasculature.
Unlike Vulgaris, rosacea lacks comodones
What are the subtypes of Rosacea?
- 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?
Rosacea affects the meibomian glands in the eyelids, reducing tear film causing dry gritty eyes. It eventually leads to sight loss if not treated.
How is does rosacea look?
Ace of clubs distribution
Rarely appears off face
Many patients get pronounced flushing on alcohol, hot drinks, emotion and spicy foods
Quick list of rosacea treatments
Topical:
- Anti-biotics
- Azeleic Acid
- Ivermectin
- Brimonidine
Non-topical:
- Anti-biotics
- Isotretinoin
- Light based therapies
what Anti-biotics are used for rosacea and why?
Metronidazole topically
Tetracyclines systemically
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
Used for Acne Rosacea
How does Ivermectin work?
Kills parasitic mites which are believed to be part of the pathogenesis of acne rosacea
