Acne Flashcards
(22 cards)
Acne Vulgaris: Definition
Acne vulgaris, also known as simply acne or “spots” is an extremely common condition most often affecting people around puberty and during the teenage years.
Most people are affected at some point during their lives, and symptoms can range from mild to severe.
Acne Vulgaris: Pathophysiology
It is caused by chronic inflammation (± localised infection) in pockets within the skin known as the pilosebaceous unit.
These are the tiny dimples in the skin that contain the hair follicles and sebaceous glands (that produce the natural skin oils and wax known as sebum).
Acne results from the increased production of sebum (typically in response to increased androgenic hormones such as during puberty) and trapping of keratin (dead skin cells) which causes blocking of the pilosebaceous unit leading to swelling and inflammation.
Swollen and inflamed units are called comedones.
Propionibacterium acnes bacteria
The Propionibacterium acnes bacteria is also felt to play a role. It is a bacteria that colonises the skin and it is thought that excessive growth of the bacteria can exacerbate acne
Acne Vulgaris: Management
In a stepwise fashion based on severity and response to treatment:
- No treatment may be acceptable if mild
- Topical benzoyl peroxide reduces inflammation, helps unblock the units and is toxic to the P. acnes bacteria
- Topical retinoids (chemicals to vitamin A) slow the production of sebum
- Topical or oral antibiotics can be used in moderate – severe acne to acute management and maintenance
- Oral contraceptive pill can help female patients to stabilise their hormones and slow the production of sebum
- Oral retinoids for severe acne (i.e. Isotretinoin) is an effective last line option, although it needs careful monitoring (see below)
Isotretinoin: Overview
Oral isotretinoin is very effective at clearing skin. It is a retinoid and works by reducing production of sebum, reducing inflammation and reducing bacterial growth.
It can only be prescribed under expert supervision (i.e. a dermatologist).
Isotretinoin: Side effects
- Dry skin and lips
- Photosensitivity of skin to sunlight
- Strongly teratogenic (harmful to the fetus during pregnancy) and patients should be careful to use contraception and must stop isotretinoin for at least a month before becoming pregnant.
- Depression, anxiety, aggression and suicidal ideation.
Patients should be screened for mental health issues prior to starting treatment. - Rarely Stevens-Johnson syndrome and Toxic Epidermal Necrolysis
Acne: Features (overview)
Acne is a disease of the pilosebaceous unit. Several different types of acne lesions are usually seen in each patient
- Comedones
- Inflammatory lesions
- Excessive inflammatory response
- Scarring
In contrast, drug-induced acne is often monomorphic (e.g. pustules are characteristically seen in steroid use)
Acne: Features - COMEDOMES
Comedones are due to a dilated sebaceous follicle
- if the top is closed a whitehead is seen
- if the top opens a blackhead forms
Acne: Features - INFLAMMATORY LESIONS
Inflammatory lesions form when the follicle bursts - releasing irritants:
- papules
- pustules
Acne: Features - EXCESSIVE INFLAMMATORY response
An excessive inflammatory response may result in:
- nodules
- cysts
Acne: Features - SCARRING
This sequence of events can ultimately cause scarring
- ice-pick scars
- hypertrophic scars
Acne fulminans: Definition
Acne fulminans is very severe acne associated with systemic upset (e.g. fever). Hospital admission is often required and the condition usually responds to oral steroids
Acne: Classification
Acne may be classified into mild, moderate or severe:
MILD: open and closed comedones with or without sparse inflammatory lesions
MODERATE acne: widespread non-inflammatory lesions and numerous papules and pustules
SEVERE acne: extensive inflammatory lesions, which may include nodules, pitting, and scarring
Acne: STEP-UP management
A simple step-up management scheme often used in the treatment of acne is as follows:
- Single topical therapy
- Combined topical therapy
- Oral antibiotics
- COCP are an alternative to oral antibiotics in women
- Oral isotretinoin
Acne treatment: ORAL antibiotics
- tetracyclines: lymecycline, oxytetracycline, doxycycline
- tetracyclines should be avoided in pregnant or breastfeeding women and in children younger than 12 years of age
- erythromycin may be used in pregnancy
- minocycline is now considered less appropriate due to the possibility of irreversible pigmentation
- a single oral antibiotic for acne vulgaris should be used for a maximum of three months
- a topical retinoid (if not contraindicated) or benzoyl peroxide should always be co-prescribed with oral antibiotics to reduce the risk of antibiotic resistance developing
- Gram-negative folliculitis may occur as a complication of long-term antibiotic use - high-dose oral trimethoprim is effective if this occurs
Acne treatment: COPC
- As with antibiotics, they should be used in combination with topical agents.
- Dianette (co-cyrindiol) is sometimes used as it has anti-androgen properties.
- However, it has an increased risk of venous thromboembolism compared to other COCPs, therefore it should generally be used second-line, only be given for 3 months and women should be appropriately counselled about the risks.
Acne treatment: Single topical therapy
- Topical retinoids
- Benzoyl peroxide
Acne treatment: Topical combination therapy
- Topical antibiotic
- Benzoyl peroxide
- Topical retinoid
Acne vulgaris: Epidemiology
- Affects around 80-90% of teenagers, 60% of whom seek medical advice.
- Acne may also persist beyond adolescence, with 10-15% of females and 5% of males over 25 years old being affected.
Acne vulgaris: Pathophysiology
Pathophysiology is multifactorial
- Follicular epidermal hyperproliferation resulting in the formation of a keratin plug.
- This in turn causes obstruction of the pilosebaceous follicle.
- Activity of sebaceous glands may be controlled by androgen, although levels are often normal in patients with acne
- Colonisation by the anaerobic bacterium Propionibacterium acnes
- Inflammation
Acne rosacea: Definition + features
Acne rosacea is a chronic skin disease of unknown aetiology.
Features
- typically affects nose, cheeks and forehead
- flushing is often first symptom
- telangiectasia are common
- later develops into persistent erythema with papules and pustules
- rhinophyma
- ocular involvement: blepharitis
- sunlight may exacerbate symptoms/
Acne rosacea: Management
- Topical metronidazole may be used for mild symptoms (i.e. Limited number of papules and pustules, no plaques)
- More severe disease is treated with systemic antibiotics e.g. Oxytetracycline
- Recommend daily application of a high-factor sunscreen
camouflage creams may help conceal redness - Laser therapy may be appropriate for patients with prominent telangiectasia
