Acne

Question 1

Explain the aetiology of acne

Answer 1

First there is accumulation of keratin and thick sebum which blocks the sebaceous gland. Androgenic activity can increase sebum production and viscosity. Propionibacterum acnes proliferates around sebum and causes mild inflammation. Then there is marked inflammation and subsequent scarring.

Question 2

What are the clinical features of acne?

Answer 2

• 3 main features for diagnosis are: Papules, pustules and comedones. Other features which may be present are erythema, nodules, cysts and scarring. In darker skin this may present as hyperpigmentation.
  Distribution is usually face, chest, back and occasionally legs/scalp.

Question 3

What are the subtypes of acne?

Answer 3

• Papulopustular,
• Nodulocystic,
• Comdeonal,
• Steroid induced,
• Acne fulminans (severe, presents suddenly with haemorrhage and ulceration)
• Acne rosacea
• Hidradenitis (affects apocrine glands of axilla/groin)

Question 4

What does the following image show?

Answer 4

Acne fulminans

Question 5

What does the following image show?

Answer 5

Hidradenitis

Question 6

What are the treatment options for acne?

Answer 6

• Reduce plugging via topical retinoids or benzyl peroxide.
• Reduce the bacteria via topical antibiotics (erythromycin/clarithromycin), oral abx (erythromycin or tetracyclines) along with benzyl peroxide to reduce resistance.
• Reduce sebum production via dianette/OCP
• Think about dietary modifications

Question 7

What are some of the potential side effects of acne treatments?

Answer 7

Topical agents can cause irritation, burning, peeling or bleaching. Oral abx can cause gastrointestinal upset. The OCP can increase DVT risk.

Question 8

Describe features of oral isotretinoin

Answer 8

• Concentrated form of vitamin A which reduces sebum, plugging and bacteria.
• Standard course is 16 weeks of 1mg/kg.
• Has several side effects eg, dry lips, nose bleeds, dry skin, myalgia, deranged liver function, raised lipids, mood disturbance and teratogenic. So women require 2 methods of contraception and monthly negative pregnancy tests.