Efficacy and safety of phenol-based partial matricectomy in treatment of onychocryptosis: A systematic review and meta-analysis.

Chemical matricectomy is an established treatment modality of onychocryptosis. In this meta-analysis, we studied the efficacy and safety profile of phenol-based matricectomy. We performed an electronic database search of PubMed, EMBASE and grey literature using the search terms '(onychocryptosis OR ingrown toe nail) AND (phenol OR chemical matricectomy)' from inception till 31-12-2020, for controlled clinical trials with phenol in one of the treatment arms and at least 10 participants in each arm. From the initial search of 335, eighteen articles were included in the final analysis. There were a total of 1655 patients, of which 856 received phenol as an intervention modality. We found that nail matrix phenolisation was associated with a 49 fewer number of recurrences per thousand patients compared with other modalities (OR: 0.28-0.57, CI 95%). It also had a reduction in 175 cases of discharge or haemorrhage per thousand patients compared with other modalities (OR: 0.25, 95% CI: 0.14-0.45). However, we found that TCA- and NaOH-based matricectomies fared better compared with phenol in incidence of postoperative discharge and haemorrhage. Patients also experienced less pain (257 fewer number per 1000, OR: 0.52, 95% CI: 0.43-0.63). Nearly, half of the included studies had some concerns about the risk of bias. As of now, phenol matricectomy combines a low recurrence rate with favourable adverse effect profile and is the preferred modality for matricectomy in grade II and III onychocryptosis.