Flashcards in Acneforms eruptions Deck (19)
Describe how acne vulgaris develops
• “Sticky” keratinocytes + increased sebum viscosity – causes them to aggregate and form a plug over follicles, leading to keratinocytes blocked in and cannot be shed when they die
• Blocked follicles = comedones.
• These can be blackheads (open) or whiteheads (closed)
• Change in commensal bacterial behaviour (Propionobacterium acnes) = inflammation
Describe the epidemiology of acne vulgaris
• Peak 15-18 years (90% incidence)
• Delayed onset in some females
• +ve family history
• M=F – but M more severe
• Psychological impact is huge
List the topical treatments available for acne vulgaris
o Retinoids – make keratinocytes “less sticky”, in am
o Benzoyl peroxide (BPO) – antibacterial, in pm
o Antibiotics: clindamycin, tetracycline, erythromycin
List the non-topical treatments available for acne vulgaris
o Antibiotics: tetracyclines or erythromycin (trimethoprim) in pregnant woman (T makes childrens teeth grey)
o Anti-androgens: combined oral contraceptives (Dianette)
o isotretinoin/Roaccutane – best for severe acne
o (Light based treatments)
What drug causes grey teeth in babies if taken while pregnant?
What is the best treatment available for severe acne vulgaris?
What is the recommended dose of isotretinoin/Roaccutane?
1mg/kg/day for 16 weeks – recommend dose to be half of this (to avoid dry skin caused by treatment)
What are the disadvantages of isotretinoin/Roaccutane?
o Highly teratogenic (pregnancy prevention programme) – teratogenic effects last for 1 month post treatment, must have negative pregnancy test before starting treatment
o Many (potential) side-effects
o Very dry skin (especially at muco-cutaneous junctions)
o Hair loss
o Mood swings/depression/suicide
o Abnormal LFT’s
What is acne rosacea?
Chronic inflammation of:
• PSU (pilo-sebaceous unit)
• Cutaneous vasculature
Describe the distribution of acne rosacea
• Ace of clubs distribution – over cheeks, nose and middle of forehead
• Unusual on non-facial sites
Describe the epidemiology of acne rosacea
• Age 30-50 years
• F > M – but M more severe
• Fair skinned/Celts are of higher risk
• Some can experience significant flushing – often in response to alcohol, spices, emotion, hot drinks etc
• “Sensitive” skin – common complaint e.g. irritation by conventional skin products
What are the subtypes of acne rosacea?
• Erythemato-telangiectatic – lots of erythema and spider veins
• Papulo-pustular – many papules and pustules
• Phymatous (M>>>F) – hyperplastic enlargement of sebaceous glands, particularly on the nose
• Ocular – affects the eye, causes dry gritty eyes, can cause keratitis and affect vision
How can you tell between acne vulgaris and acne rosacea?
Presence of comedones
What topical treatments are available for acne rosacea?
o Antibiotics – metronidazole
o Azeleic acid - can cause irritation
o Ivermectin – also used for scabies
o Brimonidine – topical vasoconstrictor, good for Erythemato-telangiectatic rosacea, reduces redness for 8hrs (special circumstances)
What is a good treatment for Erythemato-telangiectatic rosacea?
Light based treatments
What is Brimonidine?
Brimonidine – topical vasoconstrictor, good for Erythemato-telangiectatic rosacea, reduces redness for 8hrs (special circumstances)
Describe some non-topical treatments of acne rosacea
o Antibiotics – tetracyclines, (if not suitable use erythromycin), (or metronidazole)
o Isotretinoin – for severe cases, use lower doses again (0.25-0.5mg/kg), not curative in acne rosacea
o Light based treatments – best treatment for erythemato-telangiectatic rosacea
What dose of isotretinoin used for acne rosacea?
0.25-0.5mg/kg/day for 16 weeks