Nail Abnormalities in Scabies Patients: A Systematic Review

Background: Nail abnormalities can be found in patients with scabies. It is commonly misdiagnosed as onychomycosis, traumatic nail disease, or nail psoriasis. Nail changes in patients with scabies are a result of the mites burrowing activity into the stratum corneum of the epidermis, which can extend to the subungual skin of the nail. There are limited studies that have been reported regarding the incidence of nail changes in patients with scabies. Objective: To systematically review nail abnormalities in patients with scabies reported in the literature. Methods: We searched all published articles in electronic databases until August 2024 reporting patients with scabies with detailed descriptions of malformed/diseased nails using specific terms and inclusion/exclusion criteria. This systematic review presents the data as a descriptive analysis. Results: We included 32 articles reporting 33 individual patients with nail scabies. There was no significant difference in the number of scabies patients with nail abnormalities in the children (33.33%), adults (30.30%), and elderly groups (36.36%). The youngest age recorded was four months and the oldest of 92 years. Scabies were more frequent in males (60.61%). According to scabies type, 81.82% of cases of scabies with nail abnormality were crusted scabies. The most prevalent diagnosis approach was direct microscopy (84.84%), followed by histopathological examination (30.30%) and dermoscopy (12.12%). Subungual hyperkeratosis (60.60%), onychodystrophy (48.48%), discoloration (33.33%), and onycholysis (21.21%) constituted the majority of nail abnormalities. Fingernail involvement occurred in 33.33% of the patients, while combined fingernail and toenail involvement occurred in 30.30% of the patients. Conclusion: Subungual hyperkeratosis, onychodystrophy, and discoloration are the most frequent nail abnormalities found in patients with scabies. In order to provide scabies patients with adequate treatment, regular nail examinations should be performed, and further prospective studies are required to completely understand the association between risk factors and abnormalities of the nail in scabies patients.