Late-Onset Nail Changes Associated with Hand, Foot, and Mouth Disease: A Clinical Analysis of 56 Cases.

Objectives: To investigate the development and clinical characteristics of nail changes in hand, foot, and mouth disease (HFMD).

Methods: A telephone survey was conducted with the parents of patients diagnosed with HFMD in the Fourth General Hospital of Nanhai from June to August 2013 to document nail changes within 3 months of diagnosis of HFMD.

Results: Valid survey results were obtained from 273 cases. Definitive nail changes were identified in 56 patients (20.5%). More boys (25.8%) than girls (10.6%) (p < 0.01) showed changes. The age distribution ranged from 1 to 5 years, and nail changes were rare in children younger than 1 year of age (p < 0.01). Nail changes were usually seen 1 to 2 months after the onset of HFMD and lasted for 1 to 8 weeks, most for approximately 4 weeks. Toenails or fingernails could be affected and the changes were more likely to occur synchronously. Fingernails were more commonly involved than toenails. When both fingernails and toenails were involved, this typically occurred synchronously. Although there were cases with all toenails and fingernails involved (16.1%), we did not encounter any instances involving 13 to 19 nails. The nail changes mainly presented as onychomadesis. Spontaneous recovery without special treatment was the course for all patients. No relapse or new nail involvement was identified.

Conclusions: Nail change associated with HFMD usually occurs within 1 to 2 months after onset, mainly presents as onychomadesis, and is a self-limited process. Possible mechanisms are discussed.