Referral criteria for acne vulgaris are based on Referral advice: A guide to appropriate referral from general to specialist services, published by the National Institute for Health and Clinical Excellence (NICE). For people requiring referral 'immediately' or 'soon', NICE specify that 'Health authorities, trusts, and primary care organizations should work to local definitions of maximum waiting times in each of these categories. The multidisciplinary advisory groups considered a maximum waiting time of 2 weeks to be appropriate for the urgent category' [NICE, 2001].

Treatment options that are available in secondary care include:

Oral isotretinoin

• Oral isotretinoin is an effective option in secondary care [MHRA, 2008]. It must not be initiated in primary care, except under the care of a dermatology specialist. The manufacturer's Summary of Product Characteristics states that isotretinoin 'should only be prescribed by, or under the supervision of, physicians who have expertise in the use of systemic retinoids for the treatment of severe acne, and a full understanding of the risks of isotretinoin therapy and of the monitoring requirements' [ABPI Medicines Compendium, 2008b].
• Oral isotretinoin is an extremely effective treatment for acne. It is used for severe acne conditions such as nodulocystic acne, acne conglobata, scarring, or persistent acne that does not respond adequately to standard treatment or is causing significant psychological problems [Wolf, 2002].
• It is associated with potentially serious adverse effects, including teratogenicity. However, research has shown that concerns about links between isotretinoin and depression or suicide are not established [Chia et al, 2005; Magin et al, 2005b].

Laser treatment

• Laser treatment is sometimes used in the treatment of acne in secondary care. Lasers primarily work by targeting Propionibacterium acnes in the sebaceous glands. However, at present the evidence for laser therapy is limited and more trials are needed to evaluate its effectiveness [Jordan et al, 2000; Bhardwaj et al, 2005; Hamilton et al, 2009].
• Laser treatment may also be indicated for post-acne scarring.
• Lasers are expensive and their availability is limited.

Surgical treatment

• Various surgical and medical techniques may be used for the treatment of very severe acne in secondary care [Brown and Shalita, 1998].
• Purulent nodules can be incised and drained of pus.
• Comedones can be cauterized. Alternatively, comedone extraction is a technique in which entire comedones are removed. Usually this is done following several weeks of topical treatment.
• Large, tender nodules can be treated with an intralesional injection of a corticosteroid such as triamcinolone. This rapidly reduces inflammation and reduces lesion size.
• Surgical treatment of scarring is more problematic. If there is extensive superficial scarring, dermabrasion may be performed by a plastic surgeon to improve the appearance of the skin [Sharpe, 1995], although this procedure is now less common.