Seborrhoeic dermatitis is a chronic inflammatory skin condition found throughout the world, with rashes with varying degrees of redness, scaling and itching. It affects people of both sexes but is more common among men. The disease usually starts after puberty and can lead to personal discomfort and cosmetic concerns when rashes occur at prominent skin sites. Drugs that act against moulds, also called antifungal agents, have been commonly used on their own or in combination.
Do antifungal treatments applied to the skin clear up the rashes and itching of seborrhoeic dermatitis?
We included 51 studies with 9052 participants. Trials typically were four weeks long, and very few trials were longer. In all, 24 studies had some involvement of pharmaceutical companies such as funding or employment of the researchers.
Particpants taking ketoconazole were 31% less likely than those given placebo to have symptoms that persisted at four weeks of follow-up. This was seen in eight studies with 2520 participants, but wide variation was noted between studies. Ketoconazole was as effective as steroids but had 44% fewer side effects. Without causing more side effects, ciclopirox was 21% more effective than placebo in achieving clinical clearance of rashes. Treatment effect on redness, itching or scaling symptoms of the skin was less clear. Evidence was insufficient to conclude that that one antifungal was superior to other antifungals, but this observation was based on few studies. Ketoconazole and ciclopirox are the most heavily investigated antifungals and are more effective than placebo. Other antifungals might have similar effects, but data are insufficient to underpin this.
Common side effects were increased skin redness or itching, burning sensation and hair loss.
No studies measured quality of life. Only one study reported on percentage of compliance in different treatment groups. Other studies used surrogates such as acceptability to represent compliance. We therefore could not assess the effect of compliance on treatment outcomes. One study on patients with HIV reported no clear effects of treatments.
Quality of the evidence
Evidence for the effects of ketoconazole compared with placebo or a steroid was assessed to be of low quality. Evidence derived from comparison of ciclopirox versus placebo was assessed to be of moderate quality. Better quality studies with longer follow-up and better reporting are needed to enlarge the evidence base for antifungals.
Ketoconazole and ciclopirox are more effective than placebo, but limited evidence suggests that either of these agents is more effective than any other agent within the same class. Very few studies have assessed symptom clearance for longer periods than four weeks. Ketoconazole produced findings similar to those of steroids, but side effects were fewer. Treatment effect on overall quality of life remains unknown. Better outcome measures, studies of better quality and better reporting are all needed to improve the evidence base for antifungals for seborrhoeic dermatitis.
Seborrhoeic dermatitis is a chronic inflammatory skin condition that is distributed worldwide. It commonly affects the scalp, face and flexures of the body. Treatment options include antifungal drugs, steroids, calcineurin inhibitors, keratolytic agents and phototherapy.
To assess the effects of antifungal agents for seborrhoeic dermatitis of the face and scalp in adolescents and adults.
A secondary objective is to assess whether the same interventions are effective in the management of seborrhoeic dermatitis in patients with HIV/AIDS.
We searched the following databases up to December 2014: the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 11), MEDLINE (from 1946), EMBASE (from 1974) and Latin American Caribbean Health Sciences Literature (LILACS) (from 1982). We also searched trials registries and checked the bibliographies of published studies for further trials.
Randomised controlled trials of topical antifungals used for treatment of seborrhoeic dermatitis in adolescents and adults, with primary outcome measures of complete clearance of symptoms and improved quality of life.
Review author pairs independently assessed eligibility for inclusion, extracted study data and assessed risk of bias of included studies. We performed fixed-effect meta-analysis for studies with low statistical heterogeneity and used a random-effects model when heterogeneity was high.
We included 51 studies with 9052 participants. Of these, 45 trials assessed treatment outcomes at five weeks or less after commencement of treatment, and six trials assessed outcomes over a longer time frame. We believe that 24 trials had some form of conflict of interest, such as funding by pharmaceutical companies.
Among the included studies were 12 ketoconazole trials (N = 3253), 11 ciclopirox trials (N = 3029), two lithium trials (N = 141), two bifonazole trials (N = 136) and one clotrimazole trial (N = 126) that compared the effectiveness of these treatments versus placebo or vehicle. Nine ketoconazole trials (N = 632) and one miconazole trial (N = 47) compared these treatments versus steroids. Fourteen studies (N = 1541) compared one antifungal versus another or compared different doses or schedules of administration of the same agent versus one another.
Topical ketoconazole 2% treatment showed a 31% lower risk of failed clearance of rashes compared with placebo (risk ratio (RR) 0.69, 95% confidence interval (CI) 0.59 to 0.81, eight studies, low-quality evidence) at four weeks of follow-up, but the effect on side effects was uncertain because evidence was of very low quality (RR 0.97, 95% CI 0.58 to 1.64, six studies); heterogeneity between studies was substantial (I² = 74%). The median proportion of those who did not have clearance in the placebo groups was 69%.
Ketoconazole treatment resulted in a remission rate similar to that of steroids (RR 1.17, 95% CI 0.95 to 1.44, six studies, low-quality evidence), but occurrence of side effects was 44% lower in the ketoconazole group than in the steroid group (RR 0.56, 95% CI 0.32 to 0.96, eight studies, moderate-quality evidence).
Ketoconozale yielded a similar remission failure rate as ciclopirox (RR 1.09, 95% CI 0.95 to 1.26, three studies, low-quality evidence). Most comparisons between ketoconazole and other antifungals were based on single studies that showed comparability of treatment effects.
Ciclopirox 1% led to a lower failed remission rate than placebo at four weeks of follow-up (RR 0.79, 95% CI 0.67 to 0.94, eight studies, moderate-quality evidence) with similar rates of side effects (RR 0.9, 95% CI 0.72 to 1.11, four studies, moderate-quality evidence).
Clotrimazole and miconazole efficacies were comparable with those of steroids on short-term assessment in single studies.
Treatment effects on individual symptoms were less clear and were inconsistent, possibly because of difficulties encountered in measuring these symptoms.
Evidence was insufficient to conclude that dose or mode of delivery influenced treatment outcome. Only one study reported on treatment compliance. No study assessed quality of life. One study assessed the maximum rash-free period but provided insufficient data for analysis. One small study in patients with HIV compared the effect of lithium versus placebo on seborrhoeic dermatitis of the face, but treatment outcomes were similar.