Onychomadesis and Beau's Line Following Hand-Foot-and-Mouth Disease in a Seven-Year-Old Male.

Hand-foot-and-mouth disease (HFMD) is a viral infection frequently encountered in the pediatric age group. Common culprits in such manifestations are coxsackievirus A16 and human enterovirus 71. The patient presents febrile with erythematous papulovesicular exanthems in the mouth, palms, and soles. HFMD is self-limiting in nature with a rare-complication rate. Onychomadesis is proximal nail separation while Beau's lines are whitish transverse lines and considered a rare complication of HFMD. Both allude to halted nail-matrix proliferation, and the pathophysiology behind such manifestations is still not yet understood. It is hypothesized that the virus elicits an inflammatory process, inhibiting nail-matrix proliferation or immune-complexes depositing on nails creating an embolism. Onychomadesis and Beau's lines appear after four to eight weeks of HFMD disease resolution and persist for approximately 35 days. There are no serious sequelae of those manifestations, as the nail basement is still intact. We present a case of a seven-year-old Saudi male presenting with nail changes, mainly onychomadesis and Beau's lines, after 35 days of HFMD disease resolution. All causes of nail changes have been ruled out and diagnosis of onychomycosis and Beau's lines secondary to HFDM has been established.