Accurate jaundice detection: Penlight versus smartphone light

A 70-year-old woman presented for a scheduled direct intrahepatic portocaval shunt procedure. She had a history of primary biliary cholangitis and hepatocellular carcinoma treated with orthotopic liver transplantation, and recurrent portal hypertension. Using the flashlight integrated in an iPhone 12, the palate and sublingual area did not clearly demonstrate visible jaundice (Panels A & B). However, using the light-emitting diode on a Lumintop IPY365 penlight with Nichia emitter, the palate and sublingual mucosal surfaces were obviously jaundiced (Panels C & D). There was also apparent jaundice of the skin. Total bilirubin resulted at 8.0 mg per deciliter (normal value, <1.2). Handheld examination lights can significantly influence the detection of critical findings in clinical diagnostics. Three key attributes (color rendering index (CRI), color temperature, and beam shape) define their effectiveness. CRI, measured on a 0–100 scale, indicates how accurately a light renders colors. A CRI above 90, as in the example lights, ensures excellent color fidelity for precise assessments. Color temperature, measured in Kelvin (K), determines whether light appears warmer (red-tinted) or cooler (bluish). Warmer light, like the penlight's, emphasizes red–yellow tones, making conditions like jaundice more visible. Beam shape also impacts illumination. While cellphone lights often cast wide, undirected beams, penlights provide narrow, focused beams that better illuminate areas like the oropharynx. This combination of high CRI, warmer tone, and narrow beam lights enhances the clinician's ability to recognize diagnostic findings, such as jaundice, in skin and mucous membranes, emphasizing the importance of appropriate light source selection for bedside examination. The authors have nothing to report. The authors declare no conflicts of interest.