Nail involvement in patients with epidermolysis bullosa: A systematic review.

Background: Nail changes in patients with congenital epidermolysis bullosa (EB) are caused by abnormalities of the nail matrix and bed secondary to pathogenic alterations of the dermoepidermal junction. Even though ungual alterations are extremely frequent in these patients, there are scarce studies about their frequency and/or association with subtypes or clinical course of EB. Objectives: To systematically review nail abnormalities in patients with EB reported in the literature. Methods: We searched all published articles in electronic databases until June 2020 reporting patients with EB with detailed descriptions of malformed/diseased nails using specific terms and inclusion/exclusion criteria. Clinical data were extracted by two independent authors. Descriptive statistics were used. Results: We included 36 articles reporting 74 individual patients with a mean age of 28.23 years: 29 (39.2%) had dominant dystrophic EB, 27 (36.4%) had junctional EB, 8 (10.8%) had EB simplex, 6 (8.1%) had Kindler syndrome and 4 (5.4%) had recessive dystrophic EB. The most common abnormalities were dystrophic nails (48.6%), anonychia (43.2%) and pachyonychia (40.5%). Anonychia was considered the most severe abnormality and was reported more frequently in patients with junctional (62.9%) and recessive dystrophic EB (50%). Multiple organ involvement was present in 52.7% of patients. Patients with severe junctional epidermolysis bullosa and recessive dominant epidermolysis bullosa presented anonychia since birth. Conclusions: In this summary of nail abnormalities in patients with EB, anonychia was more frequent in patients with severe EB subtypes and multiple organ involvement. Further prospective studies are required to understand the associations between nail abnormalities in specific EB subtypes and/or patient outcomes.