Hand hygiene impact on the skin barrier in health care workers and individuals with atopic dermatitis

Hand washing and the use of hand sanitizers are important interventions in preventing the spread of viruses and bacteria.¹ With the onset of the coronavirus disease (COVID-19) pandemic, hand hygiene measures have intensified. Nevertheless, there are reports of increased dermatologic effects from increased hand washing, such as hand irritation.² This is especially notable in health care workers (HCWs) who already have an increased risk of irritant contact dermatitis.2, 3, 4 Furthermore, individuals who have existing skin barrier dysfunction, such as atopic dermatitis (AD), may have magnified symptoms from increased hand hygiene.

With the COVID-19 pandemic, there are reports of increased hand irritation and dryness.1, 2, 3 Previous studies on both healthy controls and subjects with AD have revealed that exposure to alcohol in hand sanitizers and detergents in soaps causes decreased natural moisturizing factor and increased transepidermal water loss (TEWL).^{5 , 6} Nevertheless, another study did not reveal significant changes in TEWL after repeated exposure of healthy skin to alcohol irritants.⁷ In addition, there are no data available on skin barrier response with skin tape strip (STS) provocation after the use of these agents, which is a useful tool for the evaluation of skin barrier integrity. In this study, we evaluated the impact of increased hand hygiene practices as a result of the COVID-19 pandemic on HCWs and patients with AD.

This institutional review board–approved study took place at National Jewish Health in Denver. Questionnaires were administered to inquire on allergy history, hand hygiene practices, and skin symptoms related to hand hygiene. Skin barrier assessment was performed by TEWL as an objective way to measure skin barrier function.⁸ In addition, TEWL was measured using the GPSkin Pro device (GPOWER Inc, Seoul, Republic of Korea) in an examination room with a controlled microclimate, first at baseline and then again after 5 STS to assess water loss in the skin. Next, the subjects used hand sanitizer provided by the study team. Finally, subjects washed their hands with soap and water, and TEWL was measured before and after 5 STS, with both TEWL and STS obtained on the dorsal surface of 1 hand. The hand sanitizer product was Symmetry Foaming Hand Sanitizer (Buckeye International, Maryland Heights, Missouri), containing ethyl alcohol, water, and polydimethylsiloxane. The soap was Symmetry Green Certified Foaming Hand Wash Unscented (Buckeye International), containing cocamide monoethanolamine and bio-terge AS-40/sodium olefin sulfonate. The TEWL area under the curve (AUC) was calculated to reveal the cumulative water loss after 5 STS for 3 treatment conditions (ie, baseline, after hand sanitizer, after hand washing). Furthermore, TEWL data were summarized as a box and whisker plot, with the box margins representing the 25th percentile to 75th percentile interquartile range, whisker lines extend for 1.5 times the interquartile range, and observations outside the whisker were marked by an open circle. The horizontal line within each box represents the median. Unpaired t test was used for the selected group comparisons. GraphPad Prism (version 9.0.2; GraphPad Prism, San Diego, California) and JMP (version 13.1.0) were used for data visualization and statistical analysis. Differences between the groups were considered significant with P value <.05.

A total of 36 adults (18-60 years) were enrolled. Subjects had either a history of AD (n = 17) or were without atopy with no history of allergies (n = 19). The groups were also stratified according to whether they were a HCW with patient contact (n = 17) or not a HCW (n = 19). There were 8 subjects with AD who were HCWs (AD + HCW), 9 subjects with AD who were not HCWs (AD + non-HCW), 9 subjects who were HCWs without atopy (NA + HCW), and 10 subjects who were without atopy and not HCWs (NA + non-HCW). There was no significant difference in age, sex, or race among the groups. All subjects with AD had mild AD skin severity. The mean eczema area and severity index (EASI) score of the AD plus HCW group was 0.7; the mean EASI score of the AD plus non-HCW group was 1.7 (EASI score: 0-72). A skin examination was completed by a physician, with the AD group having greater evidence of xerosis, erythema, and lichenification; abnormal skin findings were found in 10 subjects with AD compared with 4 subjects without AD. Of the subjects with AD, 7 reported history of contact dermatitis but none noted sensitization to the ingredients used in this study. The subjects withheld topical medications to the area sampled for 7 days previously, moisturizers were withheld for 24 hours, and they did not bathe on the day of the visit. For HCWs, study visits were scheduled at the start of the shift when applicable.

Most of the subjects in all groups reported increased hand dryness and irritation since the pandemic onset. The HCW group had significantly increased frequency of hand sanitizer use per day compared with the non-HCW group (on average 9-18 times per day in the HCW group, as compared with 2-3 times per day in the non-HCW group, P = .008). There was no difference in the use of soap and water among the groups.

Before treatment with hand sanitizer and soap, baseline TEWL AUC was significantly higher in AD + HCW and AD + non-HCW subjects as compared with NA + non-HCW subjects (Fig 1 ) (P < .05). In all 4 groups, the TEWL AUC increased after hand sanitizer use, with even greater increase after soap and water use. Both HCW groups (AD + HCW, NA + HCW) had an increased TEWL response after hand sanitizer use as compared with NA + non-HCW group (P < .01 and P < .05, respectively). Within the broader AD group, there was a significantly higher increase in the TEWL AUC after hand washing with soap and water compared with the subjects without atopy (TEWL AUC, mean ± SD, 337 ± 75 g/m² * h vs 282 ± 62 g/m² * h, respectively, P < .05). In a 4-group comparison, a significantly greater TEWL AUC after the use of soap was noted in AD + HCW workers than NA + non-HCW subjects (P < .05) (Fig 1).

Figure 1.

TEWL in subjects with AD and healthy NA controls. Study subjects were stratified as HCW or subjects with no patient contact (non-HCW). The box margins are the 25th percentile to 75th percentile interquartile range. Horizontal lines within each box represent the median. *P < .05, **P < .01. AD, atopic dermatitis; AUC, area under the curve; HCW, health care worker; NA, nonatopic; TEWL, transepidermal water loss.

It was found that HCWs have chronic use of hand sanitizer and a higher incidence of irritant contact dermatitis.⁴ This may explain the significantly higher TEWL AUC after the use of hand sanitizer among HCWs because they have an already compromised skin barrier. Moreover, HCWs also reported the use of skin emollients, most being unscented creams and lotions. Despite this, their TEWL was increased. Future studies on effects of specific emollients would be of interest because it has been found that emollients are not equally effective.⁹

The subjects with AD in our study had a significantly higher baseline TEWL AUC and highest TEWL AUC response after hand washing. It is known that individuals with AD have less natural moisturizing factor in the outer skin layers, which is needed for skin hydration.¹⁰ These data support the underlying skin barrier dysfunction present in AD. Hand washing with soap and water leads to the removal of the healthy skin products, which is congruent with previous studies.⁷

Regarding the limitations of this study, the subjects with AD had mild disease at the time of evaluation. Future studies will be useful in assessing subjects with moderate-to-severe AD. Overall, our study objectively displays the insults that occur to the skin barrier from hand sanitizer and soap products. Although frequent hand hygiene is important, this study reveals that clinicians should be mindful of counseling their patients of skin care after use of hand sanitizers and soaps.