Erratic Pulse Oximetry Pulse Rate With Preserved Oxygen Saturation in a Patient Wearing White Nail Polish: A Case Report

Pulse oximetry is widely used for noninvasive monitoring of oxygen saturation (SpO₂) and pulse rate. Because the pulse rate displayed by a pulse oximeter is derived from the peripheral photoplethysmographic waveform, it can be affected by artifact even when oxygen saturation appears normal. We report a case of an asymptomatic patient wearing white nail polish who demonstrated stable, normal SpO₂ values yet markedly erratic pulse rate readings on pulse oximetry, fluctuating rapidly between bradycardic and tachycardic ranges. Concern for arrhythmia prompted a 12‑lead electrocardiogram, which showed a normal sinus rhythm. This report highlights a practical diagnostic pitfall: nail cosmetics may have little effect on SpO₂ yet still destabilize pulse waveform detection and generate misleading pulse rate values, leading to unnecessary evaluation and erroneous clinical conclusions.