Effects of hydroquinone-containing skin-lightening creams on capillary glucose measurements before and after serial hand washings

CaHReF 20116, Yaoundé Conges hall, 23 – 26 August 2016 , PL104

Department of Internal medicine and Paediatrics, Faculty of Health Sciences, University of Buea, Buea, Cameroon

We previously showed that hydroquinone-containing skin lightening creams caused a false increase in capillary glucose measurement. The magnitude and clinical impact of this false increase is less well know. Also, it is not known if finger swabbing with water-soaked gauze or applying hand sanitizer may prevent the effect of these creams.
To determine the effect of hydroquinone-containing creams on capillary glucose measurement and the number of hand washing needed to reverse these effects.

We included 91 consenting diabetic and non-diabetic participants in an experimental study in Buea. Two glucometers with different enzymatic principles (Accu-Chek active® and OneTouch ultra2®) were used to measure fasting capillary blood glucose after initial hand washing (reference), then after application of cream, finger swabbing, sanitizer application, and a series of three hand washings respectively. Glycaemia values obtained after the various interventions were compared to the reference. Total allowable error analyses were used to assess the clinical impact of the differences in measurement.

Accu-Chek active® measured glycaemia in mg/dl changed from 134±85 (reference) to 162±98 (p<0.0001), 161±101 (p<0.0001), 172±104 (p<0.0001), 150±94 (p<0.0001), 138±86 (p=0.0003), and 132±83 (p=0.009) after cream application, finger swabbing, sanitizer application and first, second and third hand washings, respectively. Corresponding values for OneTouch ultra2® were 138±79 at baseline, then 180±100 (p<0.0001), 182±103 (p<0.0001), 202±117 (p<0.0001), 160±98 (p<0.0001), 143±90 (p=0.057), and 133±79 (p<0.0001) respectively. The mean cream-attributed glucose increment (95% CI) was 28 (18-37) mg/dl for Accu-check® and 41 (30-53) mg/dl for OneTouch ultra®. These differences were clinically significant and reversed only with two or more hand washing.

Hydroquinone-containing creams cause significant false increase in capillary glycaemia leading to potentially wrong clinical decisions. Finger swabbing with wet gauze or application of hand sanitizer are insufficient to prevent the effect of these creams. A minimum of two hand washing is required before capillary glucose measurement.

glucometers, hydroquinone, creams, hand sanitizer, water-soaked gauze