Leukotriene receptor antagonists for eczema

BACKGROUND

Eczema is a common, chronic, inflammatory skin condition that is frequently associated with atopic conditions, including asthma. Leukotriene receptor antagonists (LTRAs) have a corticosteroid-sparing role in asthma, but their role in eczema remains controversial. Currently available topical therapies for eczema are often poorly tolerated, and use of systemic agents is restricted by their adverse effect profile. A review of alternative treatments was therefore warranted.

OBJECTIVES

To assess the possible benefits and harms of leukotriene receptor antagonists for eczema.

SEARCH METHODS

We searched the following databases to September 2017: the Cochrane Skin Specialised Register, CENTRAL, MEDLINE, Embase, and the GREAT database. We also searched five trial registries, and handsearched the bibliographies of all extracted studies for further relevant trials.

SELECTION CRITERIA

Randomised controlled trials of LTRAs alone or in combination with other (topical or systemic) treatments compared with other treatments alone such as topical corticosteroids or placebo for eczema in the acute or chronic (maintenance) phase of eczema in adults and children.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. The primary outcome measures were change in disease severity, long-term symptom control, and adverse effects of treatment. Secondary outcomes were change in corticosteroid requirement, reduction of pruritis, quality of life, and emollient requirement. We used GRADE to assess the quality of the evidence for each outcome.

MAIN RESULTS

Only five studies (including a total of 202 participants) met the inclusion criteria, all of which assessed oral montelukast; hence, we found no studies assessing other LTRAs. Treatment ranged from four to eight weeks, and outcomes were assessed at the end of treatment; therefore, we could only report short-term measurements (defined as less than three months follow-up from baseline). Montelukast dosing was 10 mg for adults (age 14 years and above) and 5 mg for children (age 6 years to 14 years). One study included children (aged 6 years and above) among their participants, while the remaining studies only included adults (participant age ranged from 16 to 70 years). The participants were diagnosed with moderate-to-severe eczema in four studies and moderate eczema in one study. The study setting was unclear in two studies, multicentre in two studies, and single centre in one study; the studies were conducted in Europe and Bangladesh. Two studies were industry funded. The comparator was placebo in three studies and conventional treatment in two studies. The conventional treatment comparator was a combination of antihistamines and topical corticosteroids (plus oral antibiotics in one study).Four of the studies did not adequately describe their randomisation or allocation concealment method and were considered as at unclear risk of selection bias. Only one study was at low risk of performance and detection bias. However, we judged all studies to be at low risk of attrition and reporting bias.We found no evidence of a difference in disease severity of moderate-to-severe eczema after short-term use of montelukast (10 mg) when compared with placebo. The outcome was assessed using the modified EASI (Eczema Area and Severity Index) score and SASSAD (Six Area, Six Sign Atopic Dermatitis) severity score (standardised mean difference 0.29, with a positive score showing montelukast is favoured, 95% confidence interval (CI) -0.23 to 0.81; 3 studies; n = 131; low-quality evidence).When short-term montelukast (10 mg) treatment was compared with conventional treatment in one study, the mean improvement in severity of moderate-to-severe eczema was greater in the intervention group (measured using SCORAD (SCORing of Atopic Dermatitis) severity index) (mean difference 10.57, 95% CI 4.58 to 16.56; n = 31); however, another study of 32 participants found no significant difference between groups using the same measure (mean improvement was 25.2 points with montelukast versus 23.9 points with conventional treatment; no further numerical data provided). We judged the quality of the evidence as very low for this outcome, meaning the results are uncertain.All studies reported their adverse event rate during treatment. Four studies (136 participants) reported no adverse events. In one study of 58 participants with moderate eczema who received montelukast 10 mg (compared with placebo), there was one case of septicaemia and one case of dizziness reported in the intervention group, both resulting in study withdrawal, although whether these effects were related to the medication is unclear. Mild side effects (e.g. headache and mild gastrointestinal disturbances) were also noted, but these were fairly evenly distributed between the montelukast and placebo groups. The quality of evidence for this outcome was low.No studies specifically evaluated emollient requirement or quality of life. One study that administered treatment for eight weeks specifically evaluated pruritus improvement at the end treatment and topical corticosteroid use during treatment. We found no evidence of a difference between montelukast (10 mg) and placebo for both outcomes (low-quality evidence, n = 58). No other study assessed these outcomes.

AUTHORS' CONCLUSIONS

The findings of this review are limited to montelukast. There was a lack of evidence addressing the review question, and the quality of the available evidence for most of the measured outcomes was low. Some primary and secondary outcomes were not addressed at all, including long-term control.We found no evidence of a difference between montelukast (10 mg) and placebo on disease severity, pruritus improvement, and topical corticosteroid use. Very low-quality evidence means we are uncertain of the effect of montelukast (10 mg) compared with conventional treatment on disease severity. Participants in only one study reported adverse events, which were mainly mild (low-quality evidence).There is no evidence that LTRA is an effective treatment for eczema. Serious limitations were that all studies focused on montelukast and only included people with moderate-to-severe eczema, who were mainly adults; and that each outcome was evaluated with a small sample size, if at all.Further large randomised controlled trials, with a longer treatment duration, of adults and children who have eczema of all severities may help to evaluate the effect of all types of LTRA, especially on eczema maintenance.

Emollients and moisturisers for eczema

BACKGROUND

Eczema is a chronic skin disease characterised by dry skin, intense itching, inflammatory skin lesions, and a considerable impact on quality of life. Moisturisation is an integral part of treatment, but it is unclear if moisturisers are effective.

OBJECTIVES

To assess the effects of moisturisers for eczema.

SEARCH METHODS

We searched the following databases to December 2015: Cochrane Skin Specialised Register, CENTRAL, MEDLINE, Embase, LILACS, the GREAT database. We searched five trials registers and checked references of included and excluded studies for further relevant trials.

SELECTION CRITERIA

Randomised controlled trials in people with eczema.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures.

MAIN RESULTS

We included 77 studies (6603 participants, mean age: 18.6 years, mean duration: 6.7 weeks). We assessed 36 studies as at a high risk of bias, 34 at unclear risk, and seven at low risk. Twenty-four studies assessed our primary outcome 'participant-assessed disease severity', 13 assessed 'satisfaction', and 41 assessed 'adverse events'. Secondary outcomes included investigator-assessed disease severity (addressed in 65 studies), skin barrier function (29), flare prevention (16), quality of life (10), and corticosteroid use (eight). Adverse events reporting was limited (smarting, stinging, pruritus, erythema, folliculitis).Six studies evaluated moisturiser versus no moisturiser. 'Participant-assessed disease severity' and 'satisfaction' were not assessed. Moisturiser use yielded lower SCORAD than no moisturiser (three studies, 276 participants, mean difference (MD) -2.42, 95% confidence interval (CI) -4.55 to -0.28), but the minimal important difference (MID) (8.7) was unmet. There were fewer flares with moisturisers (two studies, 87 participants, RR 0.40, 95% CI 0.23 to 0.70), time to flare was prolonged (median: 180 versus 30 days), and less topical corticosteroids were needed (two studies, 222 participants, MD -9.30 g, 95% CI -15.3 to -3.27). There was no statistically significant difference in adverse events (one study, 173 participants, risk ratio (RR) 15.34, 95% CI 0.90 to 261.64). Evidence for these outcomes was low quality.With Atopiclair (three studies), 174/232 participants experienced improvement in participant-assessed disease severity versus 27/158 allocated to vehicle (RR 4.51, 95% CI 2.19 to 9.29). Atopiclair decreased itching (four studies, 396 participants, MD -2.65, 95% CI -4.21 to -1.09) and achieved more frequent satisfaction (two studies, 248 participants, RR 2.14, 95% CI 1.58 to 2.89), fewer flares (three studies, 397 participants, RR 0.18, 95% CI 0.11 to 0.31), and lower EASI (four studies, 426 participants, MD -4.0, 95% CI -5.42 to -2.57), but MID (6.6) was unmet. The number of participants reporting adverse events was not statistically different (four studies, 430 participants, RR 1.03, 95% CI 0.79 to 1.33). Evidence for these outcomes was moderate quality.Participants reported skin improvement more frequently with urea-containing cream than placebo (one study, 129 participants, RR 1.28, 95% CI 1.06 to 1.53; low-quality evidence), with equal satisfaction between the two groups (one study, 38 participants, low-quality evidence). Urea-containing cream improved dryness (investigator-assessed) more frequently (one study, 128 participants, RR 1.40, 95% CI 1.14 to 1.71; moderate-quality evidence) with fewer flares (one study, 44 participants, RR 0.47, 95% CI 0.24 to 0.92; low-quality evidence), but more participants in this group reported adverse events (one study, 129 participants, RR 1.65, 95% CI 1.16 to 2.34; moderate-quality evidence).Three studies assessed glycerol-containing moisturiser versus vehicle or placebo. More participants in the glycerol group noticed skin improvement (one study, 134 participants, RR 1.22, 95% CI 1.01 to 1.48; moderate-quality evidence), and this group saw improved investigator-assessed SCORAD (one study, 249 participants, MD -2.20, 95% CI -3.44 to -0.96; high-quality evidence), but MID was unmet. Participant satisfaction was not addressed. The number of participants reporting adverse events was not statistically significant (two studies, 385 participants, RR 0.90, 95% CI 0.68 to 1.19; moderate-quality evidence).Four studies investigated oat-containing moisturisers versus no treatment or vehicle. No significant differences between groups were reported for participant-assessed disease severity (one study, 50 participants, RR 1.11, 95% CI 0.84 to 1.46; low-quality evidence), satisfaction (one study, 50 participants, RR 1.06, 95% CI 0.74 to 1.52; very low-quality evidence), and investigator-assessed disease severity (three studies, 272 participants, standardised mean difference (SMD) -0.23, 95% CI -0.66 to 0.21; low-quality evidence). In the oat group, there were fewer flares (one study, 43 participants, RR 0.31, 95% CI 0.12 to 0.7; low-quality evidence) and less topical corticosteroids needed (two studies, 222 participants, MD -9.30g, 95% CI 15.3 to -3.27; low-quality evidence), but more adverse events were reported (one study, 173 participants; Peto odds ratio (OR) 7.26, 95% CI 1.76 to 29.92; low-quality evidence).All moisturisers above were compared to placebo, vehicle, or no moisturiser. Participants considered moisturisers more effective in reducing eczema (five studies, 572 participants, RR 2.46, 95% CI 1.16 to 5.23; low-quality evidence) and itch (seven studies, 749 participants, SMD -1.10, 95% CI -1.83 to -0.38) than control. Participants in both treatment arms reported comparable satisfaction (three studies, 296 participants, RR 1.35, 95% CI 0.77 to 2.26; low-quality evidence). Moisturisers led to lower investigator-assessed disease severity (12 studies, 1281 participants, SMD -1.04, 95% CI -1.57 to -0.51; high-quality evidence) and fewer flares (six studies, 607 participants, RR 0.33, 95% CI 0.17 to 0.62; moderate-quality evidence), but there was no difference in adverse events (10 studies, 1275 participants, RR 1.03, 95% CI 0.82 to 1.30; moderate-quality evidence).Topical active treatment combined with moisturiser was more effective than active treatment alone in reducing investigator-assessed disease severity (three studies, 192 participants, SMD -0.87, 95% CI -1.17 to -0.57; moderate-quality evidence) and flares (one study, 105 participants, RR 0.43, 95% CI 0.20 to 0.93), and was preferred by participants (both low-quality evidence). There was no statistically significant difference in number of adverse events (one study, 125 participants, RR 0.39, 95% CI 0.13 to 1.19; very low-quality evidence). Participant-assessed disease severity was not addressed.

AUTHORS' CONCLUSIONS

Most moisturisers showed some beneficial effects, producing better results when used with active treatment, prolonging time to flare, and reducing the number of flares and amount of topical corticosteroids needed to achieve similar reductions in eczema severity. We did not find reliable evidence that one moisturiser is better than another.