Abstract
Clinical pallor has traditionally served as a screening tool for anemia; however, its assessment is inherently subjective and lacks objectivity. Therefore, we investigate the correlation between skin and mucosal color, as measured by a spectrophotometer among 92 adult Japanese outpatients, and venous hemoglobin (Hb) values, to identify the optimal anatomical assessment site for detecting anemia. Color readings of the lower lip, lower palpebral conjunctiva, palm, nail bed, and inside of the upper arm were obtained using a spectrophotometer. Skin and mucosal color were quantified using the Lab* color scale. The color difference (ΔE*) was employed to evaluate the discriminability of anemia identification across different assessment sites. The a* values of the lip, palpebral conjunctiva, palm, and inside of the upper arm exhibited a positive correlation with Hb values and were significantly lower in the anemic group. The L* and b* values of across all sites showed no significant or less differences. While the ΔE* levels for the palpebral conjunctiva and lip were readily discernible by the human eye when comparing the normal and anemic groups, recognition at this level proved challenging for other sites. Consequently, reliance on these sites for anemia diagnosis may lead to potential oversight.