Acne Vulgaris Flashcards
Cause of acne?
Obstruction of the pilosebaceous follicle with keratin plugs which results in comedones, inflammation and pustules.
What are the 4 major factors that contribute to the formation of acne lesions?
1) Follicular hyperkeratinisation
2) Increased sebum production
3) Propionibacterium acnes colonisation
4) Inflammation
What is follicular keratonisation?
An abnormal keratinization process within the follicle leads to the formation of a keratinous plug, known as a microcomedone.
This creates an environment conducive to the proliferation of Propionibacterium acnes (P. acnes).
What hormone stimulates sebaceous gland activity, leading to increased sebum?
Androgens
Sebum & P. acnes?
Sebum serves as a nutrient source for P. acnes and contributes to the formation of a favorable anaerobic environment.
What is P. acnes?
commensal bacterium in sebaceous follicles
P. acnes and acne?
P. acnes produces lipases, proteases, and chemotactic factors that contribute to inflammation
What is a comedone?
A blocked sebaceous follice
What are the 2 types of comedones?
1) If the top is closed –> whitehead
2) If the top is open –> blackhead
Inflammatory lesions form when the blocked sebaceous follicle bursts, releasing irritants.
What are 2 inflammatory lesions?
1) papules
2) pustules
An excessive inflammatory response may result in:
1) nodules
2) cysts
What are the 2 types of acne scars typically seen?
1) ice pick scars
2) hypertrophic scars
What is acne fulminans?
Very severe acne associated with systemic upset (e.g. fever). Hospital admission is often required.
Mx of acne fulminans?
oral steroids
1st line mx of mild-mod acne?
12 week course of topical combination therapy:
1) a fixed combination of topical adapalene with topical benzoyl peroxide
2) a fixed combination of topical tretinoin with topical clindamycin
3) a fixed combination of topical benzoyl peroxide with topical clindamycin
N.B. topical benzoyl peroxide may be used as monotherapy if these options are contraindicated or the person wishes to avoid using a topical retinoid or an antibiotic
Which macrolide can be used during pregnancy?
Erythromycin
What should a topical retinoid or benzoyl peroxide always be co-prescribed with?
An oral antibiotic, to reduce the risk of antibiotic resistance developing.
What COCP can be used to help with acne?
Co-cyprindiol (due to anti-androgen effects)
Key side effect of co-cyprindiol?
Increased VTE risk –> only give for 3 months
What is a macule?
A flat mark on the skin
What is a papule?
A raised lump on the skin
What is a pustule?
Small lump containing yellow pus
What is a comodone?
skin coloured papules representing blocked pilosebaceous units
Role of topical benzoyl peroxide in acne?
Topical benzoyl peroxide reduces inflammation, helps unblock the skin and is toxic to the P. acnes bacteria
Role of topic retinoids in acne?
Slow the production of sebum
What vitamin are retinoids related to?
Vitamin A (contraindicated in pregnancy)
Give an example of topical abx used in acne
Clindamycin (prescribed with benzoyl peroxide to reduce bacterial resistance)
What is the last line option for severe acne?
Oral retinoids (i.e. isotretinoin) AKA roaccutane
How long must patients wait to get pregnant after stopping isotretinoin?
at least a month
Side effects of isotretinoin?
1) Dry skin and lips
2) Photosensitivity of the skin to sunlight
3) Depression, anxiety, aggression and suicidal ideation. Patients should be screened for mental health issues prior to starting treatment.
4) Rarely Stevens-Johnson syndrome and toxic epidermal necrolysis
