key: cord-1048740-6qd99bwe authors: Han, Hye Sung; Shin, Sun Hye; Park, Jae Wan; Li, Kapsok; Kim, Beom Joon; Yoo, Kwang Ho title: Changes in skin characteristics after using respiratory protective equipment (medical masks and respirators) in the COVID‐19 pandemic among healthcare workers date: 2021-04-29 journal: Contact Dermatitis DOI: 10.1111/cod.13855 sha: bf18b9010f95250953c6a0e5dc8068a14bed01a6 doc_id: 1048740 cord_uid: 6qd99bwe BACKGROUND: The coronavirus disease‐2019 (COVID‐19) outbreak has presented unique dermatologic challenges due to respiratory protective equipment (RPE)–related skin conditions. OBJECTIVE: To objectively evaluate the effects of RPE including medical masks and respirators on the skin barrier by measuring various physiological properties of the skin. METHODS: A cross‐sectional study was designed. Twenty healthy healthcare workers were included in this study. Skin parameters including skin hydration, transepidermal water loss (TEWL), erythema, sebum secretion, pH, and skin temperature were measured in the RPE‐covered and RPE‐uncovered areas of the face 4 and 8 hours after wearing RPE and 14 hours after not wearing RPE. RESULTS: Skin hydration, TEWL, erythema, pH, and skin temperature increased in the RPE‐covered areas after wearing RPE for 4 and 8 hours. By contrast, in the RPE‐uncovered areas, skin hydration decreased and TEWL, erythema, and pH showed minimal changes over time. Based on the repeated‐measure analysis, the changes in skin physiological properties over time were significantly different between RPE‐covered and RPE‐uncovered areas. CONCLUSION: We observed that skin physiological characteristics change with the prolonged use of RPE such as medical masks and respirators. These changes may lead to various adverse skin reactions after long‐term use. globalization, has forced us to recognize the importance of foundational measures of disease control, including "physical distancing," "physical isolation," and universal infection control precautions including handwashing and the use of personal protective equipment (PPE). Because the virus is mainly spread via respiratory droplets, respiratory protective equipment (RPE) such as medical masks (surgical masks) or respirators (filtering facepiece) is arguably the most important piece of PPE. 1, 2 However, prolonged daily use of RPE itself can lead to physical and psychological disturbances especially among healthcare workers (HCWs). 3 In fact, there has been an increasing number of reports on RPE-related skin conditions among HCWs fighting against COVID-19, with the prevalence estimated up to 74%. [4] [5] [6] [7] [8] [9] A recent study even reported that 21% of HCWs suffered from work absenteeism due to various RPE-related facial dermatoses. 10 However, there is insufficient objective data regarding the effect of RPE on the skin barrier. Therefore, this study aimed to objectively evaluate the effects of RPE such as wearing medical masks or respirators on the skin barrier by measuring various physiological properties of the skin. Twenty healthy HCWs with no history of skin diseases or skin changes at the test sites were included in the study. Exclusion criteria were (a) the use of topical or systemic corticosteroids, retinoids, or other medications that can alter the skin condition for 1 month before inclusion and during the study; and (b) nonadherence to the study protocol. The study protocol was approved by the Institutional Review Board (approval number: P2007-1336, P&K Skin ResearchCente), and the study conformed to the guidelines of the Declaration of Helsinki. After being evaluated for eligibility, participants were randomly assigned to wear either a Korean Filter 94 respirator (KF94 respirator; 3M Corporation, St. Paul, MN, USA), which is equivalent to the European FFP2 respirator, or a medical mask (surgical mask; Kimberly-Clark, Roswell, GA, USA). Participants were given the same face wash and moisturizer (Laviderm; HP&C Ltd, Seoul, Korea) to use for at least one week before the start of the study. Participants were prohibited from using all other skincare products other than the provided face wash and moisturizer and receiving any skincare procedures that could alter their skin condition until the end of the study. For each participant, the facial skin was divided into an RPEcovered area and an RPE-uncovered area, and two points were designated for measurement in each region. The points of measurement were defined such that the same point could be selected at each measurement time (Figure 1 ). The two values obtained from the two points in each RPE-covered and uncovered area were averaged to obtain a single value for each region. Measurements were performed four times in total. At baseline, participants gently washed their faces with water and were acclimatized to an indoor environment without RPE for 30 minutes. Baseline measurements (V0) were performed at approximately 8 AM on the first day. After wearing the RPE for 4 hours, the second measurements (V1) were taken again at around 12 PM. After wearing the RPE for another 4 hours, the third measurements (V2) were taken at around 4 PM. After three measurements on the first day, participants were instructed to return to their homes and not wear the RPE until the next morning. The fourth measurements (V3) were performed the next morning at around 8 AM (approximately 14 hours after the last use of RPE). Between the measurement periods, all participants were allowed to continue their usual routines, but only in the outpatient setting. Furthermore, all participants were guided to adhere to the study protocol that is wearing either a KF94 respirator or a medical mask without additional protective equipment such as face shields or other facial coverings. The skin temperature of the RPE-covered area was evaluated using infrared (IR) thermography. IR thermography is a noninvasive method that detects IR energy emitted from an object and converts it to temperature to display an image of temperature distribution. At each measurement time, the facial temperature of the perioral region of each participant was recorded using a 14-bit digital IR camera (FLIR SC660 QWIP; FLIR Systems, Danderyd, Sweden). Data were analysed using the SPSS package (SPSS for Windows, version 24.0; SPSS, Inc, Chicago, IL). Repeated measures analysis of variance (RM-ANOVA) was used to analyse the change in skin physiological properties and temperature due to RPE use by time and group. Initial data were analysed using the Mauchly test of sphericity, with the Greenhouse-Geisser adjustment to correct for the lack of sphericity. The Bonferroni method was used to control the type I error rate for post hoc procedures. Consolidated data were analysed using independent sample t tests. A P value <.05 was considered statistically significant. The baseline demographic characteristics of the participants are summarized in Table 1 . There was no significant difference in sex, age, or average duration of RPE use per day between the KF94 respirator group and the medical mask group (Table 1 ). At the baseline, the KF94 respirator-covered area (KCA) and medical mask-covered area (MCA) had significantly lower skin hydration values than the KF94 respirator-uncovered area (KUA) and medical mask-uncovered area (MUA). After wearing the RPE for 4 and 8 hours, skin hydration in the KCA and MCA remained significantly lower than that in the KUA and MUA ( forehead. 14,15 However, after wearing RPE for 4 and 8 hours, hydration and TEWL of the RPE-covered area increased over time. This maybe because, in the RPE-covered area, continuous expiration and occlusion increase local humidity, skin temperature, and sweating. 16 Roberge et al 17 has previously shown that relative humidity in the dead space inside an N95 mask increased over time, reaching levels as high as 93% after just 60 minutes of use. Clinically, this microclimate with increased temperature and humidity would make the facial skin condition similar to diapered skin with local disruption of the skin barrier. 18 It is also known that a higher content of water in the SC can facilitate dermal absorption of chemicals. 16, 19 Thus, RPE-covered skin can become more susceptible to various allergens or chemical irritants, which can increase the risk of contact dermatitis. Second, similar to the changes in skin hydration and TEWL, skin erythema also increased over time in the RPE-covered area. Furthermore, an increase in skin temperature on the RPE-covered area was confirmed by IR thermography. Erythema may be due to the direct pressure effect of RPE or maybe a result of cutaneous blood vessel dilatation, which is a normal physiological response to increased temperature. However, skin erythema and high temperature may also indicate inflammation and increased skin permeability. 20 Third, sebum levels increased both in the RPE-covered area and the RPE-uncovered area. This can be explained by the circadian changes in sebum secretion. 21 However, the increase in sebum values was greater in the RPE-covered area compared with the RPEuncovered area. Cunliffe et al 22 have reported a significant relationship between skin temperature and sebum excretion rate, where sebum secretion was increased by 10% as the local temperature increased by 1 C. In another study, Cunliffe et al 23 also found that sebum excretion rate rose significantly following occlusion with surgical tape, confirming the view that an obstruction to the outflow of sebum with keratin hydration increases sebum secretion rate. Therefore, the increase in skin temperature and occlusion would have led to a greater increase in sebum secretion in the RPE-covered area compared with the uncovered area. Clinically, excessive sebum secretion may lead to enlarged pores, acne, seborrheic dermatitis, or "Maskne," which is a variant of acne mechanica that occurs in the O-zone due to the use of PPE. 24, 25 Last but not least, skin pH also continuously increased in the RPE-covered area over time. The acidic milieu of the skin is important for epidermal permeability barrier homeostasis, restoration of the disrupted barrier, and nonspecific antimicrobial defence of the skin. [26] [27] [28] [29] The RPE-covered area is constantly exposed to the oral fluid that carries both dangerous and innocuous viral and bacterial agents. 30 Lastly, the changes in skin hydration, erythema, sebum secretion, and pH were greater in KF94 respirators than in medical masks, although the differences were not statistically significant. However, because our study was limited by a small sample size and short study period, further studies are needed to clarify this finding. As mentioned above, the limitations of our study include the small sample size and a relatively short study period. Further studies with larger sample sizes and longer study periods are needed to fully elucidate the long-term or cumulative effects of RPE-related skin changes. Furthermore, noninvasive in vivo measurements of skin biophysical properties are inevitably affected by the instrument-and environment-related variables as well as individual-originating factors. 32 Hence, efforts to minimize these variables are essential when performing these studies. In our study, we performed measurements in temperature-and relative humidity-controlled rooms according to T A B L E 2 Recommendation and prevention strategies for RPErelated skin reactions How to wear masks • Wear a well-fitting mask. • If there is excess pressure or discomfort on any one particular area, use masks in different ways to avoid sustained friction and pressure on the same site. • Avoid prolonged (>6 h/day) RPE use. • In case of prolonged RPE use, RPE should be removed and readjusted every 2 hours. Skin care during mask use • A skin-care regime suitable and specific for sensitive skin should be used daily. • The skin should be cleaned routinely using gentle, low-pH facial cleansers. • Over-heated water, ethanol, or other skin-irritating products should be avoided. • Noncomedogenic emollients should be used daily and should be applied again at least one hour before wearing masks. • Petroleum jelly or baby napkin cream can be used before wearing masks. • Working in a cool environment is recommended. • Remove masks for a few minutes in case of heavy sweating. Abbreviations: RPE, respiratory protective equipment. the manufacturer's guidelines. Furthermore, to maintain the same skin condition at the baseline, we guided the participants to wash their faces and acclimatize in the measurement rooms for 30 minutes, as recommended by EEMCO guidance for the in vivo assessment of biochemical properties of the human skin. 12 In addition, the RPEuncovered area measurements were included as relevant controls for each participant, which served as its own control for each individual. Therefore, while it is important to strictly adhere to PPE guidelines in this pandemic, measures should be implemented to protect the skin barrier, thereby preventing the paradoxical situation in which protective measures become a risk factor for various dermatoses. While adverse skin reactions may not be considered severe conditions, they are often known to reduce effective workforce due to work absenteeism, and can cause additional medical expenses. To this end, several recommendations regarding the use of RPE have been suggested by experts around the world. 7, 33, 34 Based on the previous recommendations and our study results, we have summarized the prevention strategies for RPE-related skin reactions in Table 2 . The COVID-19 pandemic has forced the global population to adopt new ways of living, including the daily and compulsory use of masks. Wearing masks is crucial for preventing airborne diseases and cannot be easily substituted. However, as shown in various reports, wearing RPE for extended periods, as has occurred in the era of COVID-19, can have potentially serious consequences. Therefore, dermatologists must identify the mechanisms responsible for adverse skin conditions due to RPE use in order to devise proper preventive measures. A Schlieren optical study of the human cough with and without wearing masks for aerosol infection control Mass masking in the COVID-19 epidemic: people need guidance Prevalence of depression, anxiety, and insomnia among healthcare workers during the COVID-19 pandemic: a systematic review and meta-analysis Skin reactions to non-glove personal protective equipment: an emerging issue in the COVID-19 pandemic Skin damage among health care workers managing coronavirus disease-2019 Adverse skin reactions to personal protective equipment against severe acute respiratory syndrome-a descriptive study in Singapore COVID-19 and personal protective equipment: treatment and prevention of skin conditions related to the occupational use of personal protective equipment Adverse skin reactions among healthcare workers during the coronavirus disease 2019 outbreak: a survey in Wuhan and its surrounding regions The prevalence, characteristics, and prevention status of skin injury caused by personal protective equipment among medical staff in fighting COVID-19: a multicenter, cross-sectional study Personal protective equipment induced facial dermatoses in healthcare workers managing coronavirus disease 2019 Short-term skin reactions following use of N95 respirators and medical masks EEMCO guidance for the assessment of transepidermal water loss in cosmetic sciences Closed-chamber transepidermal water loss measurement: microclimate, calibration and performance Facial skin mapping: from single point bio-instrumental evaluation to continuous visualization of skin hydration, barrier function, skin surface pH, and sebum in different ethnic skin types Distribution of skin surface pH on the forehead and cheek of adults Absorption of chemicals through compromised skin Protective facemask impact on human thermoregulation: an overview Full-body skin mapping for six biophysical parameters: baseline values at 16 anatomical sites in 125 human subjects Hydration disrupts human stratum corneum ultrastructure Thermally activated TRPV3 channels Analysis of circadian and ultradian rhythms of skin surface properties of face and forearm of healthy women The effect of local temperature variations on the sebum excretion rate Pilosebaceous duct physiology. 2. The effect of keratin hydration on sebum excretion rate Efficacy and possible mechanisms of botulinum toxin treatment of oily skin Diagnostic and management considerations for "maskne" in the era of COVID-19 pH directly regulates epidermal permeability barrier homeostasis, and stratum corneum integrity/cohesion The pH of the skin surface and its impact on the barrier function Generation of free fatty acids from phospholipids regulates stratum corneum acidification and integrity Stratum corneum acidification in neonatal skin: secretory phospholipase A2 and the sodium/hydrogen antiporter-1 acidify neonatal rat stratum corneum Recognition of aerosol transmission of infectious agents: a commentary Study of the micro-climate and bacterial distribution in the deadspace of N95 filtering face respirators Non-invasive in vivo methods for investigation of the skin barrier physical properties Consensus of Chinese experts on protection of skin and mucous membrane barrier for health-care workers fighting against coronavirus disease 2019 European task force on contact dermatitis statement on coronavirus disease-19 (COVID-19) outbreak and the risk of adverse cutaneous reactions Changes in skin characteristics after using respiratory protective equipment (medical masks and respirators) in the COVID-19 pandemic among healthcare workers The patients in this study provided written informed consent regarding the publication of their clinical information and photos. This research was supported by the Chung-Ang University Research Grants in 2020. The authors have no conflict of interest to declare. The study protocol was approved by the Institutional Review Board (approval number: P2007-1336). The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.