Acne Vulgaris Flashcards
What is acne vulgaris?
Acne vulgaris is a disorder of the pilosebaceous follicles found in the face and upper trunk. At puberty androgens increase the production of sebum from enlarged sebaceous glands that become blocked.
Propionibacterium acnes is involved in lesion production although its exact role is unclear. It is a skin commensural but in acne it colonises the follicles.
Comedones (follicles impacted and distended by incompletely desquamated keratinocytes and sebum) may be open (blackheads) or closed (whiteheads).
Inflammation leads to papules, pustules and nodules.
Acne can cause severe psychological problems, undermining self-assurance and self-esteem at a vulnerable time in life.
Acne tends to affect boys more than girls.
Pathophysiology of acne vulgaris
There is sebaceous gland hyperplasia and excess sebum production and androgens stimulate sebaceous glands to enlarge and produce more sebum which is more prevalent during puberty.
Abnormal follicular differentiation. In normal follicles, keratinocytes are shed as single cells into the lumen and then excreted. In acne, keratinocytes are retained and accumulate due to their increased cohesiveness.
Cutibacterium (Propionibacterium) acnes colonisation. These gram-positive, non-motile rods are found deep in follicles and stimulate the production of pro-inflammatory mediators and lipases.
Inflammation and immune response. Inflammatory cells and mediators efflux into the disrupted follicle, leading to the development of papules, pustules, nodules, and cysts.
Causes of acne vulgaris
External factors occasionally contribute to acne, including mechanical trauma, cosmetics, topical corticosteroids, and oral medicines (corticosteroids, lithium, iodides, some antiepileptic drugs).
Endocrine disorders resulting in hyperandrogenism may also predispose patients to developing acne. Acne may be associated with PCOS.
Presentation of acne vulgaris
Acne usually presents with a greasy skin with a mixture of comedones, papules and pustules, which present just after puberty and continue for a variable number of years, usually stopping in late teens or early 20s but uncommonly continuing well into adulthood.
The face is affected in 99% of cases, the back in 60% and the chest in 15%.
Acne runs a variable course with marked fluctuations.
What is nodulocystic acne?
Nodulocystic acne: severe acne with cysts. Cysts can be painful. They may occur in isolation or be widespread over the face, neck, scalp, back, chest and shoulders.
Which scale is used to assess the psychosocial impact of acne vulgaris?
The severity of the condition varies enormously between individuals. It is unsightly but the degree of distress is sometimes disproportionate.
The Assessment of the Psychological and Social Effects of Acne (APSEA) scale is an example of a validated tool which allows dermatologists to assess the psychosocial impact
Which scoring system is commonly used to assess the severity of acne vulgaris?
The clinical severity of Acne vulgaris can be graded using several systems.
The Leeds Scoring system counts and categorises lesions into inflammatory and non-inflammatory ranging from 0 for mild acne to 12 for the severest form (nodules, cysts, scars). Other systems simply refer to mild, moderate and severe acne.
Risk factors of acne vulgaris
Age 12-24 years.
Genetic predisposition.
Precipitating drugs.- androgens, corticosteroids, antiepileptics, isoniazid, lithium.
Having a greasy skin type.
Differentials for acne vulgaris
Acne rosacea: usually presents in middle age or later in life.
Folliculitis and boils: may present with pustular lesions similar to those seen in acne.
Milia: Small keratin cysts that may be confused with whiteheads. They tend to be whiter than acne whiteheads and are most commonly seen around the eyes.
Perioral dermatitis.
Pityrosporum folliculitis: predominates on the trunk.
Investigations for acne vulgaris
Usually no investigations are required.
Investigations are occasionally required to explore a possible underlying cause - eg, virilising tumour.
Skin lesion culture may be warranted in patients who do not respond to treatment, to exclude Gram-negative folliculitis.
Why is it important to treat acne vulgaris?
Severe acne is a serious disease in that it is disfiguring, has enormous psychological impact and requires referral to a dermatologist.
Usually acne is a mild and self-limiting condition but teenagers are very sensitive about it and so it is essential to be empathetic as well as providing advice and reassurance.
Patients are traditionally advised to keep the face clean, although there is no convincing evidence linking acne with poor hygiene.
What is the information given to everyone with acne?
To avoid over cleaning the skin (which may cause dryness and irritation) — acne is not caused by poor hygiene.
To use non-comedogenic make-up, cleansers and/or emollients with a pH close to the skin if needed.
To avoid picking and squeezing spots which may increase the risk of scarring.
That acne treatments are effective but take time to work — usually up to 8 weeks.
That acne treatments may irritate the skin, especially at the start of treatment — concentration or application frequency may need to be reduced if skin irritation occurs.
What is the management of mild to moderate acne?
Consider prescribing a single topical treatment such as:
- A topical retinoid (for example adapalene or isotretinoin [if not contraindicated]) alone or in combination with benzoyl peroxide. Retinoids are contraindicated in pregnancy and breastfeeding.
- A topical antibiotic (for example clindamycin 1%) — antibiotics should always be prescribed in combination with benzoyl peroxide to prevent development of bacterial resistance.
- Topical benzoyl peroxide and topical erythromycin are usually considered safe in pregnancy if treatment is felt to be necessary.
- Azelaic acid 20%- may cause hypopigmentation.
Creams or lotions may be preferable for people with dry or sensitive skin and less greasy gels may be preferable for people with oily skin.
Concentration or application frequency of topical treatments may need to be reduced or lowered if skin irritation occurs.
Advise the person that frequency of application can be gradually increased from once or twice a week to daily if tolerated.
Treatment for people with moderate acne not responding to topical treatment
If response to topical preparations alone is inadequate consider adding an oral antibiotic, a tetracycline, such as lymecycline or doxycycline (for a maximum of 3 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.
Macrolide antibiotics (such as erythromycin) should generally be avoided due to high levels of P. acnes resistance but can be used if tetracyclines are contraindicated (for example in pregnancy if treatment is felt to be necessary).
Change to an alternative antibiotic if there is no improvement after 3 months, the person is unable to tolerate side effects or acne worsens while on treatment.
If the person does not respond to two different courses of antibiotics, or if they are starting to scar, refer to a dermatologist for consideration of treatment with isotretinoin.
Which drug treatment can be used as an alternative to systemic antibiotics in women?
Combined oral contraceptives (if not contraindicated) in combination with topical agents can be considered as an alternative to systemic antibiotics in women.
Oral progesterone only contraceptives or progestin implants with androgenic activity may exacerbate acne, third and fourth generation combined oral contraceptives are generally preferred.
Co-cyprindiol (Dianette®) or other ethinylestradiol/cyproterone acetate containing products may be considered in moderate to severe acne where other treatments have failed but require careful discussion of the risks and benefits with the patient.
