• CKS has made recommendations based on UK guidelines on the management of shingles from the British Society for the Study of Infection [BSSI, 1995], recommendations for the management of herpes zoster from an international panel of experts [Dworkin et al, 2007], and reviews of the literature [Mounsey et al, 2005; Wilson, 2007].
• The advice on when to return to school or work is based on guidance on infection control in schools and other childcare settings from the Health Protection Agency [HPA, 2006], and UK guidelines on shingles management [BSSI, 1995].

Simple analgesia

• These recommendations combine guidelines on the management of herpes zoster in the immunocompetent host [International Herpes Management Forum, 2002] and recommendations for the management of herpes zoster from a internationally representative panel [Dworkin et al, 2007]. CKS has also taken into account discussion in several review papers, as there is no evidence from controlled trials for paracetamol, nonsteroidal anti-inflammatory drugs (NSAIDs), codeine, or opioid analgesics for treating the pain of acute shingles [Johnson and Whitton, 2004; Dworkin et al, 2007; Schmader and Dworkin, 2008].
• Opinion differs between reviews on the approach to simple analgesia, with some recommending paracetamol and a weak opioid [Johnson and Whitton, 2004] and others suggesting paracetamol or NSAIDs [Schmader, 2007]. A UK guideline states that oral or topical NSAIDs have not been shown to be effective for post-herpetic neuralgia [BSSI, 1995], but no evidence of ineffectiveness is discussed, and it is unclear what their role is in acute shingles.

Drugs for neuropathic pain

• The recommendation to offer a trial course of amitriptyline or pregabalin (or gabapentin if there is a local decision to prefer gabapentin over pregabalin) is based on guidance issued by the National Institute for Health and Clinical Excellence on drug treatment of neuropathic pain in adults [NICE, 2010]. For further information, see the CKS topic on Neuropathic pain - drug treatment.
• Having reviewed the evidence for a number of neuropathic conditions (including post-herpetic neuralgia), the NICE guidance development group (GDG) treated the term 'neuropathic pain' as a blanket condition regardless of the underlying cause; the GDG considered this to be helpful and practical for non-specialist healthcare professionals and patients. However, condition-specific recommendations were made if robust evidence on clinical efficacy and cost-effectiveness existed (as in the case of painful diabetic neuropathy), or where the evidence was clearly uncertain and insufficient to alter current clinical practice (as in the case of trigeminal neuralgia). The GDG acknowledged that evidence for treating a particular neuropathic pain condition with a particular aetiology is often extrapolated to other neuropathic pain conditions with other aetiologies, although there is little evidence to support the validity of this [NICE, 2010].
• It is reasonable to suppose that drugs used to treat the pain of post-herpetic neuralgia may therefore have an effect in treating the acute pain of herpes zoster [Dworkin et al, 2007].

Strong opioids

• Stronger opioids (e.g. dihydrocodeine, morphine) are thought to be useful for some people [Johnson and Whitton, 2004]. The CKS recommendation to seek specialist advice regarding their use is based on extrapolated guidelines from the International Herpes Management Forum on post-herpetic neuralgia [International Herpes Management Forum, 2002]. These state that stronger opioids (e.g. oxycodone, morphine) may be considered for treatment of post-herpetic neuralgia, but they are usually used in a pain clinic.

Treatments not recommended

• CKS has not recommended the use of corticosteroids to treat acute shingles because although some evidence suggests that prednisolone may increase the rate of skin healing and relief of pain, and improve quality of life [Wood et al, 1994; Whitley et al, 1996], evidence is insufficient to confirm the effectiveness and safety of corticosteroids to prevent post-herpetic neuralgia [He et al, 2008]. There is also concern that corticosteroids may cause dissemination of herpes zoster [Wareham, 2006] and the adverse effect profile limits their use [Mounsey et al, 2005].
• Pregabalin is not recommended. It is licensed for neuropathic pain, but further post-marketing safety data are needed (black triangle) [BNF 55, 2008].

• This recommendation is based on guidelines for the management of shingles from the British Society for the Study of Infection [BSSI, 1995], guidelines on the management of herpes zoster in the immunocompetent host from the International Herpes Management Forum [International Herpes Management Forum, 2002], recommendations for the management of herpes zoster from an internationally representative panel [Dworkin et al, 2007], and the following evidence.
• Benefits and harms of antiviral drugs
• Evidence indicates that antiviral drugs reduce the severity and duration of shingles and are generally well tolerated. Some evidence also indicates that the use of antivirals can help prevent post-herpetic neuralgia, but this is less conclusive [BSSI, 1995; Volpi et al, 2005; Tyring, 2007].
• For people who are at low risk of complications (e.g. young people, and those with mild pain and rash, or truncal involvement), the potential benefits of antiviral treatment are unknown, but it may reduce the risk of post-herpetic neuralgia. The safety of the antivirals also provides a favourable benefit-to-risk ratio [Dworkin et al, 2007].
• A systematic review of the primary care management of acute herpes zoster [Lancaster et al, 1995] found that the most common adverse events with aciclovir were headache and nausea (no major adverse events were reported). In the control groups, the incidence of adverse effects was similar.
• Aciclovir resistance is very rare in immunocompetent people [Ahmed et al, 2007].
• Timing of treatment
• Evidence suggests little difference in resolution of zoster-associated pain when antiviral therapy is initiated before 48 hours compared with 48–72 hours after rash onset [Wood et al, 1998].
• Evidence is lacking for the benefit of delayed initiation of antiviral treatment, but observational data from two uncontrolled studies found no significant difference in the persistence of pain between people starting treatment within 72 hours and those starting treatment after 72 hours. The authors of review articles discussing this concluded that, although evidence is not conclusive, there may be a benefit from starting antiviral treatment 72 hours or more after rash onset [Christo et al, 2007; Dworkin et al, 2007; Tyring, 2007]. Recommendations from an international panel of experts advise consideration of prescribing after 72 hours if the person is older or has severe pain, as these are strong risk factors for post-herpetic neuralgia [Dworkin et al, 2007]. CKS has based its recommendations on this evidence and feedback from expert reviewers.
• Pregnant women
• Herpes zoster is not a risk to the fetus [Pass et al, 1999]. Expert feedback suggests this is because of pre-existing varicella antibodies. CKS recommends seeking specialist advice for pregnant women with shingles because the safety of antiviral treatment in pregnancy has not been firmly established; therefore, pregnant women should only be treated if the potential benefits of treatment outweigh the risk to the fetus. Most pregnant women are thought to be at lower risk of post-herpetic neuralgia because of their relatively younger age [Dworkin et al, 2007].
• Immunocompromised people
• CKS recommends treating immunocompromised people with oral antivirals only if the rash is localized and not severe, as immunocompromised people are more at risk of complications (e.g. cutaneous dissemination, visceral dissemination, and multidermatomal involvement with deep-tissue destruction) [BSSI, 1995; International Herpes Management Forum, 2002; Tyring, 2007].
• CKS recommends seeking specialist advice for if the person is systemically unwell, has severe shingles, or is severely immunocompromised, because in this group, there is a higher risk of disseminated disease and complications [Dworkin et al, 2007]. Resistance to antiviral treatment can also be a problem [Ahmed et al, 2007].
• Children
• CKS has not recommended antiviral treatment for otherwise healthy children, because in this group shingles is usually mild and post-herpetic neuralgia is rare [Feder and Hoss, 2004]. In addition, aciclovir, valaciclovir, and famciclovir are not licensed for this purpose in children [BNF for Children, 2007; BNF 55, 2008].

• Immunocompetent adults
• Evidence from clinical trials suggests that famciclovir and valaciclovir have similar or superior efficacy and safety/tolerability compared with aciclovir for the treatment of herpes zoster [Tyring, 2007]. In view of this, CKS suggests that the decision on which antiviral to use should be made by the clinician, taking into account cost and compliance issues for each individual.
• Immunocompromised adults
• There is only very limited evidence from clinical trials on the efficacy of oral antiviral regimens in immunocompromised adults.
• The recommendation that standard doses of oral antivirals should be used (in individuals who do not need referral) until all lesions have healed is based on expert consensus [Dworkin et al, 2007], and expert opinion from a narrative review [Ahmed et al, 2007].
• Pregnant women
• CKS has recommended seeking specialist advice for pregnant women with shingles because the safety of antiviral treatment in pregnancy has not been firmly established. Pregnant women should only be treated if the potential benefits of treatment outweigh the risk to the fetus. Most pregnant women are thought to be at lower risk of post-herpetic neuralgia because of their relatively younger age [Dworkin et al, 2007].
• Topical antivirals
• CKS has not recommended the use of topical antiviral treatment because a systematic review (search date: December 2006) found insufficient evidence to determine whether its use during an acute episode of shingles reduces the risk of post-herpetic neuralgia [Wareham, 2006].

• CKS could find no specific UK guidelines on the referral of people with shingles and therefore has made general recommendations on the basis of the opinion of an international panel [Dworkin et al, 2007] and a US expert [Weinberg, 2007].
• In cases of ophthalmic shingles, the recommendations are based on those in a US article [Gnann, 2006] and a review on managing ophthalmic shingles in primary care [Opstelen and Zaal, 2005].
• In pregnancy, the safety of antiviral treatment is not firmly established [Dworkin et al, 2007].
• CKS has recommended seeking specialist advice for severely immunocompromised people, or immunocompromised people with a widespread rash or who are systemically unwell, regarding choice, route, and duration of antiviral drug therapy. These people are at higher risk of disseminated disease and complications, and may need intravenous antiviral treatment [BSSI, 1995; Ahmed et al, 2007; Dworkin et al, 2007]. Resistance to antiviral treatment can also be a major problem in immunocompromised people [Ahmed et al, 2007].
• CKS has recommended referral of a person with a reactivation of shingles, as it is atypical to see reactivations in younger people with no history of malignancy and no immune deficit [Rashid et al, 2007], and therefore underlying immunocompromise may need to be excluded.
• CKS recommends seeking specialist advice for recurrent shingles in immunocompromised people. Shingles typically recurs once prophylaxis is stopped in immunocompromised people, and recurrences are more likely to be associated with aciclovir-resistant strains [Ahmed et al, 2007]. There is indirect evidence from randomized placebo-controlled trials that long-term aciclovir substantially reduces the risk of herpes zoster in people receiving a bone marrow transplant [Prentice and Hann, 1983; Lundgren et al, 1985; Perren et al, 1988], and from an observational study that treatment with aciclovir, valaciclovir, or famciclovir prevents herpes zoster in people given immunosuppressive therapy for multiple myeloma [Vickrey et al, 2009].