Acne

Question 1

Draw and label a simple pilosebaceous unit?

Answer 1

Note: the oil sebum is secreted by the sebaceous ducts and acts an emollient for the skin

Question 2

Describe the 4 step pathogenesis of acne?

Answer 2

Increase sebum excretion rate from the sebaceous glands.

Hypercornification of the follicular lining leading to obstruction of the pilosebaceous ducts. This forms a microcomedo.

Colonisation of Propionbacterium acnes. This is normal a commensal microbe, but which proliferates in a sebum rich environment.

Inflammation.

Question 3

Which hormones are sebum associated with?

Answer 3

Androgens: reason for increased incidence of acne at puberty in line with increased levels of androgens.

Question 4

What is seborrhoea?

Answer 4

Oily skin due to excess sebum production

Question 5

What does the following picture show.

Answer 5

Open Comodone aka blackhead

Distended pilosebaceous unit which is impacted with keratin and lipids.

Question 6

Describe and name the following image and state the key features?

Answer 6

Closed comones (whiteheads)

Pale slightly evelvated small papules.

More likely to become imflamed as the follicles can burst more easily.

Question 7

1. When do pustules and papules form in acne and how long do they last for?

Answer 7

Superficial inflammatory lesions.

They form when a closed comodone bursts releasing irritant FFA in to the surrounding dermis.

Last 1-2 weeks.

Question 8

Describe the features of nodules in acne, symptoms, time span?

Answer 8

Nodules occur when there is an excessive inflammatory response in the surrounding dermis.

They are painful and last a few weeks to months.

Question 9

When would you see cysts and abcesses in acne?

Answer 9

True cysts are very rare in acne.

Abcesses are unique to acne conglobata an acne which tends to start in adult life.

Question 10

What is the potential acne sequale in those who do not have scarring?

Answer 10

After the inflammatory lesions of acne settle patients may have:

Erythematous macules.

Hyper/hypo pigmeneted macules.

Question 11

What are the different scars which can form in acne?

Answer 11

Ice pick

Atrophic

Hypertrophic/ keloid

Usually occur after the larger inflammatory lesions settled, aka deep pustules, papules or cysts.

Question 12

Which factors may aggravate acne?

Answer 12

Greasy cosmetics and hair products

Heat and humidity

Excessive washing

Manipulation of lesions

Exogenous medications

Question 13

What is the 1st line treatment in mild to moderate acne?

Answer 13

Topical treatments:

Retinoids

Antibiotics

Antibacterials

Should be applied twice a day

Question 14

Describe the key features of topical retinoids, what they are, how they help acne, side effects?

Answer 14

Vitamin A derivatives

Comedolytic (remove surface keratin, unblocking the pores and allowing the drainage of microcomodomes.

Should be used in comodomal acne.

Side effects:

Teratogenic

Erythema and irrittaion

Photosensitivity

Question 15

Name and describe the key features of topical antibacterials, what they are, how they help acne, side effects?

Answer 15

Benzoyl Peroxide and Azelaic Acid

Work by reducing the number of P. acne bacteria.

Side effects incluide dryness and irritaition

Indicated for mild-moderately severe papulopustular acne

Question 16

Describe the key features of topical antibiotics, what they are, how they help acne, side effects?

Answer 16

Anti microbial and anti inflammatory effect

Erythromycin or Clindamycin

Can be combined withe Benzoyl Peroxide: Benzomycin or Duac

Problems: Antibiotic resistance, don’t use for more than 6 months

Indicated for mild - moderately severe papulopustular acne

Question 17

What are the inidications for starting systemic antibiotics in acne?

Answer 17

Moderate to severe acne

Failure of topical treatments

Involvement of the chest or back

Presence of scarring or marked post inlfammtory hyperpigmentation.

Question 18

What are the different systemic antiobiotics used to treat acne?

Answer 18

1st Line:

Tetracylines: Lymecyclin or Doxycycline

Not for children <12 or to women trying to conceive

2nd Line:

Macrolides

3rd Line: Trimethoprim

Note biggest issue is resistance: paticularly seen with erythromycin and staph

Question 19

What are the hormanal treatments used for acne, and who are they indicated for?

Answer 19

Dianette a Oral contraceptive contains an oestrogen and anti androgen.

It is indiated for females patients with moderate to severe patinets who have failed to respond to systemic antibiotics.

Contraindicated in those at risk of DVT and pregnant ladies or those breast feeeding.

Question 20

What are the systemic retinoids which are used, and what is the indication?

Answer 20

Isotretinonin

Severe acne

Active acne with scarring

Resistant disease

Acne which rapidly reoccurs on the cessation of antibiotics

Acne causing psychological distress

Question 21

What are the important point when prescribing isotretinoin, what are the main side effects and what are the baseline investogations you should do?

Answer 21

Highly teratogenic, women of child bearing age should be on 2 forms of contraception.

Increased lipids

Deranged LFTs

Arthralgia/myalgia

Dry mucosa and skin

Epistaxis

Ix:

Pregnancy test

LFTs

U/E’s

Lipids

FBC

Question 22

Name some treatments for scarring?

Answer 22

Microdermabarsion

Demabrasion

Laser resurfacing (risk of hyperpigmentation)

Intralesional steroids for keloid scars

Question 23

Name 3 types of acne including the most common form?

Answer 23

Acne vulgaris (most common)

Acne conglobata (abcsesses)

Acen fulminans