ACNE VULGARIS
DEFINTION:
A chronic cutaneous disorder characterized by inflammation of the
pilosebaceous follicles.
EPIDEMIOLOGY:
- incidence: common
- age of onset:
- risk factors:
- stress, hormonal changes, drugs, external agents
- see below
PATHOGENESIS:
- androgenic stimulation of the sebaceous glands -> abnormal
keratinization -> retention hyperkeratosis -> obstructed pilo-sebaceous
follicle -> increased production of sebum -> prolif-eration of
Propionibacterium acnes (P. acnes) -> follicular wall rupture ->
inflammation -> closed comedo (whitehead) -> inflammed papule ->
pustule
- P. acnes provides a source of lipases responsible for the
break-down of sebum to the irritative free fatty acids
responsible for the inflammatory response upon rupture of the
follicular wall
2. Types of Comedones
- widely-dilated orifice with blackened tip (? melanin)
- usually not accompanied by inflammation
- easily treated
2. Closed (Whiteheads)
- microscopic orifice with a white tip
- follicular wall of the pilosebaceous follicle ruptures ->
sebum into the surrounding dermis -> inflammation -> lesion
- lesion - papule or pustule if inflammation close to
surface
- lesion - papule or nodule if inflammation deep to surface
3. Triggering Factors
- anticonvulsants (dilantin), antidepressants (lithium),
antituberculants (isoniazid), steroids
2. Stress
3. Hormonal Changes
- tend to increase the rate of sebum formation
4. External Agents
- greasy or oily suntan or sunscreen preparations
- heavy make-up bases
- grooming agents
- acnegenic agents - oils, greases, waxes from petroleum and
animal and vegetable oils
CLINICAL FEATURES:
- whiteheads and blackheads
2. Moderate to Severe Cases
- papules, pustules, nodules, cysts
3. Sites of Involvement
- face (forehead, cheeks, chin) - back
- chest - shoulders
4. Complications
- scarring - deep or shallow pits
INVESTIGATIONS:
MANAGEMENT:
- a chronic condition with initial treatment phase (6-12
weeks) followed by long-term therapy
- dietary restrictions appear to play no role except
psychological
2. Medications
- pure comedonal acne (white- and blackheads) - Grade I
acne
2. Preparations
- Retin-A, Retisol-A, Stieva-A, Vitamin A Acid
- topical creams (0.025-0.1%), gels (0.01-0.025%), and
liquid (0.05%)
- apply cream every other day then increase frequency and
strength (liquid) over a period of weeks to avoid irritation
and peeling
3. Side Effects
- increased susceptibility to sunburn
2. Benzoyl Peroxide (Topical)
- keratolysis (fine desquamation)
- decreases level of free fatty acids
- bacteriostatic for P. acnes
- decrease inflammation of acne lesions
2. Indications
- mild papular acne (Grade II acne)
3. Preparations
- Benoxyl, Benzac AC 5, Benzagel, Oxy 5 Vanishing Formula
- gels (2.5-10%) applied as a thin film every other day
then every day
4. Side Effects
- irritant or allergic contact dermatitis (in <1%)
3. Combination Therapy
- papulopustular and cystic acne (Grade III acne)
2. Combinations
- benzoyl peroxide + tretinoin +/- topical antibiotics
(tetracycline, erythromycin, clindamycin bid)
- use benzoyl peroxide in the am and tretinoin in pm
4. Systemic Antibiotics
- 500-1000 mg/day po tid for 6-8 weeks then reduce to 250
mg/day until clinical improvement
- use with topical anti-acne agents (tretinoin, benzoyl
peroxide)
- indications: severe or persistent pustulocystic acne
(Grades III & IV)
- contraindications: children <10 years; pregnancy
2. Alternatives
- erythromycin, clindamycin, doxycycline, minocycline
5. Isotretinoin (Retinoic Acid)
- recalcitrant severe cystic acne
2. Preparations
- 13-cis retinoic acid
- give orally for 4-5 months by a Dermatologist
- 1 mg/kg/day for 20-24 weeks
3. Side Effects
- many and contraindicated in pregnancy
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