Recent papers on dermatology
Dermatology GPSI Dr Julian Peace reviews five papers that could be useful to everyday general practice.
Is minocycline the best antibiotic for acne?
The paper Don't use minocycline as first-line oral antibiotic in acne. McManus P, Iheanacho I. BMJ 2007;334:154.
Method The authors reviewed the evidence for the use of minocycline as a first-choice antibiotic. They performed a Cochrane review of 27 published trials comparing minocycline with placebo or other active treatment.
Results Although effective, evidence that minocycline could be considered more effective than other treatments was weak and limited to poor-quality trials with questionable results.
Conclusion In the absence of supportive evidence, minocycline should no longer be considered as a first-line antibiotic for moderate to severe acne. Other tetracyclines should be considered in its place.
What I am going to do now Minocycline has been used for many years as a drug of choice. This is despite it being significantly more expensive than the alternative tetracyclines, its potential for causing a lupus-like syndrome, autoimmune hepatitis and, unique among its peers, sometimes a potentially irreversible slate-grey discolouration of the skin. Other tetracyclines are safer, just as easy to take and no more likely to cause antibacterial resistance. Lymecycline and doxycycline have once daily dose regimes, are as effective and cheaper.
How should you treat warts in a cash-strapped NHS?
The paper To freeze or not to freeze: a cost effectiveness analysis of wart treatment. Keogh-Brown MR et al. Br J Dermatol 2007;156:687-92.
Method Warts are common and there is no agreement on the best method to treat them – if they need treating in the first place.
This paper looked at the cost-effectiveness of OTC treatments as well as those administered by GPs and practice nurses.The authors designed a decision-analytic Markov simulation model based on systematic review evidence to estimate the cost-effectiveness of various treatments. The outcomes measured were percentage of patients cured, cost of treatment and incremental cost-effectiveness ratio for each treatment, compared with no treatment, after 18 weeks.
Results In terms of pure cost-effectiveness, the application of duct tape to the wart came out top – although evidence for its efficacy is somewhat sparse. Topical salicylic acid – either as an OTC preparation or a prescribed item – was more cost-effective than cryotherapy. GP-administered cryotherapy came out as most expensive of all.
Conclusion Patients want quick cures. Cryotherapy, when effective, fulfils that criterion but does not score well in terms of cost-effectiveness. When nearly 50% of warts resolve within 18 weeks with no treatment, the cheapest therapies have much to recommend them.
What I am going to do now If treatment is deemed necessary, OTC salicylic acid preparations or duct tape should be recommended. Cryotherapy should not be thought of as a first-line treatment for viral warts.
Does it matter what dressing you use for venous leg ulcers?
The paper Dressings for venous leg ulcers: systematic review and meta-analysis. Palfreyman S et al. BMJ 2007;335:244-8.
Method This extensive study used systematic review and meta-analysis to compare the effectiveness of different dressings applied to venous leg ulcers. A total of 254 studies were examined, of which 42 were included.
Several different types of dressing were considered – simple, non-adherent, hydrocolloid, foam, hydrogel and alginate – both alone and in combination.
Results The results showed no statistically significant difference in terms of ulcers healed between any of the dressing types.
Conclusion The type of dressing applied under compression does not appear to affect ulcer healing.
What I am going to do now Compression, if tolerated, remains the mainstay of treatment for venous ulcers. This study shows that the dressing applied under compression does not really matter and, as a consequence, we should recommend the most cost-effective – a simple, non-adherent dressing.
Can patients with eczema use older, established steroid creams just once a day?
The paper Established corticosteroid creams should be applied only once daily in patients with atopic eczema. Williams HC. BMJ 2007;334:1272.
Method Atopic eczema is common in both adults and children. Health costs are comparable with the treatment of diabetes. Topical steroids are the mainstay of treatment and most are applied at least twice daily.
The author of this paper recommended that established creams can be applied just once daily based on 10 randomised, controlled trials comparing once-daily versus more frequent application of topical steroids within the same potency group. The findings are summarised in a UK Health Technology Assessment report and NICE guidance.
Results Although some statistically significant outcomes favoured twice-daily applications, there was no consistency in which outcome was improved. More importantly, none of the studies found clear evidence that applying topical steroids more than once a day produced better overall clinical outcomes. Clear evidence of a faster response with more frequent use or a better response in subgroups such as children was lacking. No data were given on relapse rates.
Conclusion Reducing the frequency of application of older creams to once daily does not seem to result in loss of efficacy and could lead to fewer local side-effects. Using topical steroids just once a day may be more convenient for patients and may save costs if established preparations are used.
What I am going to do now It seems logical that by halving the frequency of application, that prescribing costs can be driven down by a similar percentage. This only holds true if older (cheaper) steroids are used. By reducing the frequency of application, side-effects can be reduced and compliance may increase.
The biggest obstacle to change is habit. The evidence is good for once-daily application. I, for one, will be giving it a go.
Does dimeticone clear head lice?
The paper Does dimeticone clear head lice? Drug and Therapeutics Bulletin 2007;45:52-5.
Method Hedrin is a novel treatment for head lice. It is a 4% dimeticone lotion applied to the hair and scalp. In this paper it was considered in the context of other options.
Results Although head lice rarely cause disease, they almost invariably cause anxiety in sufferers and carers and social stigmatisation for the carrier. Dimeticone provides a novel, physical treatment that does not expose a child to potentially noxious chemicals. It is well tolerated – in particular, it is not absorbed transdermally – it is suitable for people with asthma, comparable in cost to the alternatives and, as a physical treatment, does not have the potential to cause resistance in the louse. On the basis of one randomised, controlled trial, it is also as effective as phenothrin lotion. This trial involved 214 young people and 39 adults with active infestation.
Conclusion The authors concluded that on current evidence it seems reasonable to regard dimeticone as a first-line alternative to malathion, permethrin or phenothrin, particularly for parents who do not wish to use conventional insecticides.
What I am going to do now Head lice should only be treated if there is evidence of live lice. Dimeticone lotion should be considered an effective, first-line treatment.
Dr Julian Peace is a GPSI in dermatology in Sheffield
Competing interests None declared