Acne Flashcards
(21 cards)
What are the two types of acneiform eruptions?
Acne Vulgaris
Acne Rosacea
Describe the pathophysiology of acne vulgaris
Disease of the pilo-sebaceous unit (PSU)
Combination of increased stickiness of keratinocytes and increased sebum viscosity measns that keratinocytes aren’t shed properly and form a plug which blocks the hair follicle.
The change in keratinocytes and sebum cause a change in commensal bacterial behaviour which causes inflammation.
What types of skin lesions may be present in acne vulgaris? What determines the type of lesion(s) that form?
Depends on inflammation
Papules, pustules, nodules, cysts
Can eventually form scars
Which bacteria is involved in acne vulgaris?
Propionobacterium acnes
- anaerobic, gram-positive rod
Which keratinocytes are mitotically active?
Basal keratinocytes
What is a comedo?
Blocked hair follicle - formed by unshed keratinocytes
What is the pilo-sebaceous unit? Where are they most prevalent?
Units made up of the hair follicle, sebaceous gland and erector piniae muscle
Most prevalent on the face, chest and back
Describe the two types of commodone
Open; keratinocyte plug is visible. Appears black (“blackhead”) due to the melanin present in the dead keratinocytes.
Closed; skin closes over the top of the comedo
Describe the topical treatment options for acne vulgaris
Retinoids (vitamin A derivatives) - e.g. Isotretinoin
- anticomodonal; reduces stickiness of keratinocytes
Benzoyl peroxide (BPO)
- oxidising agent; anti-inflammatory and antibacterial
Topical antibiotics
- clindamycin
- tetracycline
- erythromycin
——-> should not be used on their own, due to risk of resistance (use with BPO at least)
Describe the non-topical treatment options for acne vulgaris
Oral antibiotics
- tetracyclines (NOT children or pregnant women)
- erythromycin
- (trimethoprim)
Anti-androgens
- oral contraceptives
- Dianette
Oral isotretinoin
- stubborn acne only, very effective
Describe the disadvantages of isotretinoin
Highly teratogenic when taken orally
- centrofacial malformations, cardiac and large vessel malformations
- must have a negative pregnancy test before starting
Many potential side effects
- Hair loss, mood swings, depression, abnormal LFTs, hypertriglyceridaemia
Commonly causes dry skin
Very expensive
What type of drug is isotretinoin?
Retinoid; vitamin A derivative
Can be administered topically and/or orally
What is acne rosacea?
Chronic inflammation of the PSU and cutaneous vasculature
Describe the classic distribution of acne rosacea
“Ace of clubs” distrubution; nose, cheeks and forehead but spares the periorbital areas
Rarely occurs on non-facial areas of skin
Which skin types are more prone to acne rosacea?
Fair skin types (i.e. 1 and 2)
List the four subtypes of acne rosacea
Erythemato-telangiectatic
Papulo-pustular
Phymatous - soft tissue hyperplasia, esp. nose
Ocular - altered tear film, causes dry gritty eyes
Which type of acne has a much much higher incidence in males than females?
Phymatous acne rosacea
Describe the topical treatment options for acne rosacea
Topical antibiotics - metronidazole
Azelic acid
Ivermectin
Brimonidine (vasoconstrictor)
Describe the non-topical treatment options for acne rosacea
Oral antibiotics - tetracycines, erythromycin, metronidazole
Isotretinoin (used less often than in acne though)
Light-based treatments (used more often than for acne)
Describe the role of light-based treatments in the management of acne rosacea
Light treats background telangectasia and erythema
Long-term benefits (effects can last 5-10 years)
List five less common types of acne
Infantile acne Acne conglobata Acne fulminans Pyoderma faciale Acne inversa
