Acne

Question 1

Pathogenesis

Answer 1

1. +Sebum production secondary to excess androgen
2. Hypercornification of pilosebaceous duct forming keratin plugs
3. Overgrowth of P. acnes
4. Inflammation

Question 2

Important advice and considerations

Answer 2

1. Minimise aggrevating factors->steroids/danazol/some COP/phenytoin/lithium. Ensure all topical creams and noncomedogenic
2. If evidence of androgen excess->hirsutism, obesity, menstrual irregularities->investigate
3. Assess emotional and social impact
4. Consider occupation->oils which can exacerbate
5. Do not squeeze acne lesions->+depth, severity and scarring
6. Use a mild skin cleansing->not due to dirt, so excess washing is not helpful. Low irritant, pH balance, soap free BD
7. Eat a healthy diet
8. Avoid over-exposure to the sun

Question 3

Therapeutic groups to treat acne

Answer 3

Comedolytics->salicyclic acid, isotretinoin, tretinoin
Antibacterials->benzyl peroxide, clindamycin, erythromycin
ANti-androgens (females)->cyproterone in COCP, spirinolactone

Question 4

Mechanism of salicyclic acid

Answer 4

Removes keratin plugs

Question 5

Mechanism of retinoids

Answer 5

Decrease plugging, suppresses inflammation

-ve proliferation of keratinocytes

Question 6

Risk factors

Answer 6

Age 12-14
Genetic predisposition
Greasy skin
Medications

Endocrine
Dietary
Female
Obesity/insulin resistance
\+Androgen

Question 7

Investigations

Answer 7

Clinical
Consider if evidence of ++androgen->hormonal profile: elevated total testosterone, dehydroepiandrostenedione sulphate (DHEA-S), luteinising hormone (LH), follicle stimulating hormone (FSH)

Question 8

Management overview

Answer 8

1. Adress social/emotional concerns
2. Consider investigations if necessary
3. Medication

Question 9

Mild, comedonal/papulopustular

Answer 9

1. Adapalene or tretinoin gel (oily skin), cream in dry
2. If not adequate in 6 weeks->add benzoyl peroxide or clindamycin or erythromycin gel in the morning
3. For truncal->salicyclic acid once daily

Question 10

Moderate / truncal/ nodules

Answer 10

1. Use tretinoin (increased dose) or benzoyl peroxide 5%
2. Add doxycyclin daily PO
3. If not adequate in 6 weeks-> +dose or change antibiotic
4. 3-6 month antibiotic course recommended
5. For women: Combined oral contraceptives that are likely to improve acne include those containing cyproterone, desogestrel, drospirenone or gestodene as the progestin

Question 11

Moderate-severe, cystic

Answer 11

1. Tretinoin, benzoyl peroxide, doxicycline->change antibiotic, increase dose (6 week trial)
2. Females: cyproterone acetate, spirinolactone
3. Consult dermatologist to start isotretinoin->usually 6-9 month course

Question 12

Adverse effects of isotretinoin

Answer 12

Teratogenic
early flare of the acne
cheilitis
sun sensitivity
dry skin and dermatitis especially involving the forearms
facial erythema
epistaxis
lethargy
myalgia
joint stiffness

Question 13

When a patient is on isotretinoin, during each visit what should you check

Answer 13

Fasting lipids
Liver function
bHCG