History
A 25-year-old woman presents to the dermatology clinic with a long history of a facial eruption that has been getting worse progressively over the past few years. Some of the lesions on her face are painful at times and sometimes heal with scarring. The rest of her skin is unaffected. Her GP had prescribed several prolonged courses of tetracycline antibiotics with little benefit, and she was unable to tolerate erythromycin due to its gastrointestinal side effects. She took Dianette (oral contraceptive pill) for several months but this had to be stopped as it was significantly lowering her mood.
Examination
There are numerous comedomes, particularly on her forehead, pustules, papules, inflam-matory lesions, cysts and atrophic scars (Fig. 67.1). There is sparing of the periorbital skin.
Questions
• What is the likely diagnosis?
• What is the underlying pathophysiology?
• What treatment would you suggest?
Medicine
This patient had been suffering from acne vulgaris on her face for many years. This is a common condition, which usually starts around puberty but can persist into the third or fourth decades. Acne lesions develop from sebaceous glands that produce lipid material called sebum. Blockage of the sebaceous glands results in comedomes, which appear as small monomorphic papules, often on the forehead and cheeks. Comedomes can be closed (whiteheads) or open (blackheads) and are usually the primary acne lesions. In addition, there is increased sebum production and numbers of Proprionibacterium acnes bacteria within the ducts, which leads to inflammation around the glands. Painful cysts can then form which may heal with scarring.
Various factors are known to play a role in the development of acne including androgens, testosterone, oestrogens, sweating, occlusive oils and steroids. Women may develop acne as part of the polycystic ovarian syndrome. The impact of acne on a patient’s well-being should not be underestimated. Many acne patients lose self-confidence and feel depressed as a consequence of their highly visible skin disease. Patients should therefore be treated early and effectively.
Most patients start on the acne treatment ladder with topical therapies (antibiotics, retin-oids, benzoyl peroxide), and then progress to systemic treatment with antibiotics (tetra-cyclines, erythromycin), hormone preparations (females) and finally isotretinoin.
Isotretinoin is a vitamin A-derived medication, which is highly effective at treating and usually ‘curing’ acne through its action of shrinking-down the sebaceous glands by 90 per cent. Despite its high efficacy it is usually reserved for treating resistant or severe acne owing to its unfavourable side-effect profile.
Isotretinoin is teratogenic (90 per cent risk of birth defects). Therefore, women of child-bearing age who are sexually active need a reliable form of contraception. The reduction in sebum production means patients taking the medication may suffer from severely dry lips and skin. Other side effects include a temporary rise in liver enzymes and lipids.
Mood change and depression are potential side effects and therefore care should be taken
when prescribing the medication to those with a history of depression or mental illness.
Patients usually take a cumulative target dose of isotretinoin between 120 and 150 mg/kg body weight over six to nine months. Most patients benefit from long-term elimination of their acne.
Residual scarring may be treated with topical retinoids, chemical peels, laser resurfacing and tiny pinch-grafts.
KEY POINTS
• Acne is a common condition affecting up to 80 per cent of Western populations.
• Acne lesions include comedomes, papules, pustules, cysts and eventually scarring.
• Isotretinoin is a highly effective treatment for acne but needs careful prescribing and monitoring.
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