CRD summary

This review concluded that, although there is a paucity of evidence, there are data to suggest that topical aloe vera may be effective in healing first- and second-degree burns. Given the limited number of small and, overall, quite different poor-quality trials, the authors are right to suggest that their conclusions should be treated with caution.

Authors' objectives

To evaluate the effectiveness of topical aloe vera for the treatment of burn wounds.

Searching

MEDLINE, CINAHL, the Cochrane Database of Systematic Reviews, the Cochrane CENTRAL Register, DARE, HealthSTAR, Health Source: Nursing/Academic Edition, ACP Journal Club, Chinese Science and Technology Database, China Academic Database, Thai Theses Online, Thai Index Medicus Database, South-East Asia Index Medicus, Thai Medical Index and Medicinal Plant Database were searched up to 2004. The search terms were reported and no language restrictions were applied. In addition, the reference lists of retrieved articles were screened, and authors and experts in the field of burn therapy or herbal medicine were contacted for further studies.

Study selection

Assessment of study quality

The validity of randomised controlled trials (RCTs) was assessed and scored using the Jadad scale. The validity of non-RCTs was not assessed. The authors did not state how many reviewers performed the validity assessment.

Data extraction

Two reviewers independently extracted the data. Means and standard deviations for the time to healing were calculated. If standard deviations could not be obtained, equal variance and normal distribution of data were assumed and standard deviations were calculated on the basis of reported p-values. Study authors were contacted where possible for additional data.

Methods of synthesis

Results of the review

Four controlled clinical trials (n=371) were included. Two studies were RCTs, one study used a within-patient design, and one study was a controlled trial but with no information relating to randomisation.

Two studies were published in Thailand, one study in India and one in China. The two RCTs scored only 2 out of a maximum of 5 points on the Jadad scale. One study was reported as blinded.

The pooled WMD for healing time was significantly shorter for aloe vera compared with control (8.79 days, 95% CI: 2.51, 15.07, p=0.006) in one blinded RCT and one non-RCT of participants (n=138) with first- and second-degree burns. There was no significant statistical heterogeneity between the two studies. A third study reported a better success rate for first- or second-degree burns in the aloe vera group compared with the silver sulfadiazine group (95% versus 83%). The fourth study, which involved participants with second- or third-degree burns, reported that the epithelialisation rate measured by healing size was higher in the aloe vera plus vaseline gauze group than in the vaseline gauze alone group for post skin grafting on both day 5 (2.695 +/- 0.618 mm versus 1.294 +/- 0.169 mm) and day 8 (5.837 +/- 0.266 mm versus 3.953 +/- 0.326 mm).

Two studies (n=92) reported adverse effects. One study reported 40% irritation or itching in the aloe vera group and 44% in the sulfadiazine group. The second study reported discomfort and pain classified as mild (92.6%) or moderate (7.4%) in both groups, which was relieved by oral analgesic. No allergic reactions or eczema were reported in any of the included studies.

Authors' conclusions

Differences between products and outcome measures make specific conclusions difficult. However, there is some evidence to suggest that aloe vera may be effective intervention in healing first- and second-degree burns.

CRD commentary

The review question was clear, but not specifically defined with respect to the participants. Several databases were searched, experts in the field were contacted for additional studies, and no language or publication restrictions were applied; this suggests that the risk of language and publication bias is minimal. The methods used to select the studies were not described, so it is not known whether any efforts were made to reduce reviewer error and bias. The authors did, however, take steps to reduce reviewer error and bias during the extraction of data. Study validity was only assessed for randomised trials, which makes it difficult to assess the reliability of the other data. The measurement of outcomes was subjective and clinicians were, in general, not blinded to intervention category, thereby introducing the possibility of measurement bias. The authors explored possible sources of variation, although the significance of these investigations was limited by the small numbers of patients and studies. Given the paucity of evidence from a limited number of small and, overall, quite different poor-quality trials, the authors are right to suggest that their conclusions should be treated with caution.

Implications of the review for practice and research

Practice: The authors did not state any implications for practice.

Research: The authors stated that further well-designed clinical trials specifying details of the types of aloe vera products used are required to determine the effectiveness of aloe vera for burn wound healing. In addition, there is a need to evaluate complete epithelialisation using at least two independent outcome assessors to minimise the potential for bias.

Funding

Thailand Research Fund; School of Pharmacy Grants for Young Researchers.

Bibliographic details

Maenthaisong R, Chaiyakunapruk N, Niruntraporn S, Kongkaew C. The efficacy of aloe vera used for burn wound healing: a systematic review. Burns 2007; 33(6): 713-718. [PubMed: 17499928]

Other publications of related interest

Vogler BK, Ernst E. Aloe vera: a systematic review of its clinical effectiveness. Br J Gen Pract 1999;49:823-8.

Indexing Status

Subject indexing assigned by NLM

MeSH

Aloe; Burns /drug therapy; Clinical Trials as Topic; Humans; Phytotherapy /methods; Plant Preparations /therapeutic use; Treatment Outcome; Wound Healing /drug effects

AccessionNumber

12007003049

Database entry date

01/12/2008

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.