To the Editor: Due to the recent COVID-19 pandemic, people are wearing disposable masks more often than ever. The prolonged use of disposable masks has markedly increased cases of facial dermatitis, including irritant contact dermatitis, allergic contact dermatitis, and exacerbations of preexisting atopic dermatitis.1 Patch tests help differentiate possible etiologies and exclude allergic contact dermatitis; however, objective data are lacking to help determine the validity of positive allergens.2 Here, we undertook an observational study to investigate the clinical manifestation and patch test results of patients with facial dermatitis induced by wearing disposable masks.
Korean patients older than 18 years of age with facial dermatitis diagnosed by dermatologists from the Department of Dermatology at Kangnam Sacred Heart Hospital after the outbreak of COVID-19 between January 2020 and July 2020 were included in the study. Clinically, 27 patients whose lesions and symptoms worsened after wearing a mask wereestablished as the mask group and 70 patients who developed facial dermatitis due to other causes were established as the control group. Both groups were recruited and distinguished using a questionnaire.2 Demographic features, clinical manifestations, objective bioengineering measurements (transepidermal water loss and stratum corneum hydration), and patch test (Korean standard series)3 results were analyzed in this study.
The mean duration of disease was 6.24 months among the patients in the mask group and 22.87 months in the control group (Table I ). The distribution of skin lesions was similar in both groups except for the chin area, where skin lesions were more frequently observed in the mask group (14.81%; 4 of 27 patients). Erythema and papules were the most common characteristics of the skin lesions in both groups; however, hyperkeratosis (22.22%; 6 of 27) and xerosis (11.11%; 3 of 27) were significantly more frequent in the mask group.
Table I.
Comparison between mask group and group induced by other causes with clinical manifestation
| Clinical manifestation | Induced by mask (n = 27) |
Induced by other causes (n = 70) |
|---|---|---|
| Disease duration, mean (SD), month∗ | 6.24 ± 6.00 | 22.78 ± 30.37 |
| Mean stratum corneum hydration (SD), A.U. | 61.93 ± 21.03 | 58.94 ± 19.33 |
| Mean TEWL (SD), g/m2/hr | 16.98 ± 6.53 | 21.11 ± 20.88 |
| Patients, Number (%) | ||
| Distribution∗ | ||
| Centrofacial | 18 (66.66) | 9 (33.33) |
| Peripheral | 45 (64.28) | 25 (35.71) |
| Location of eczematous skin lesions | ||
| Forehead | 8 (29.62) | 23 (32.85) |
| Nose | 3 (11.11) | 7 (10) |
| Perioral | 6 (22.22) | 17 (24.28) |
| Chin∗ | 4 (14.81) | 4 (5.71) |
| Ears | 4 (14.81) | 10 (14.28) |
| Cheek | 13 (48.14) | 38 (54.28) |
| Others | 3 (11.11) | 8 (11.42) |
| Cutaneous signs | ||
| Erythema | 19 (70.37) | 46 (65.71) |
| Hyperkeratosis∗ | 6 (22.22) | 3 (4.28) |
| Pustule | 3 (11.11) | 18 (25.71) |
| Papule | 6 (22.22) | 22 (31.42) |
| Excoriation | 0 | 2 (2.85) |
| Vesicle | 2 (7.40) | 10 (14.28) |
| Xerosis∗ | 3 (11.11) | 1 (1.42) |
| Hyperpigmentation | 1 (3.70) | 10 (14.28) |
| Edema∗ | 2 (7.40) | 0 |
| Cutaneous symptoms | ||
| Itching | 15 (55.55) | 51 (72.85) |
| Flushing∗ | 6 (22.22) | 4 (5.71) |
| Stinging/heating sensation | 4 (14.81) | 11 (15.71) |
Each patient has 1 or more skin lesions, cutaneous signs, or symptoms.
A.U., Arbitrary unit; SD, standard deviation; TEWL, transepidermal water loss.
P value < .05.
In patch test results (Table II ), the mask patch tested positive more frequently to potassium dichromate (25.92%; 7 of 27) and 4-tert-butylphenol-formaldehyde resin (14.81%; 4 of 27). Positive reactions to N-isopropyl-N-phenyl-4-phenylenediamine (7.40%; 2 of 27), formaldehyde (11.11%; 3 of 27), and thimerosal (14.81%; 4 of 27) were more common in the mask group, but the difference was not statistically significant. Interestingly, these substances are known components of disposable facial masks. In addition, 11 patients in the control group (15.71%; 11 of 70) had negative reactions to all the items in the patch tests, while only 1 patient in the mask group did (3.70%; 1 of 27).
Table II.
Comparison between the mask group and control group in the patch test results
| Patch test items | Induced by mask (n = 27) | Induced by other causes (n = 70) |
|---|---|---|
| 1. Nickel (II) sulfate hexahydrate | 15 (55.55%) | 31 (44.28%) |
| 2. Lanolin alcohol (wool alcohol) | 1 (3.70%) | 2 (2.85%) |
| 3. Neomycin sulfate | 0 | 2 (2.85%) |
| 4. Potassium dichromate∗ | 7 (25.92%) | 7 (10%) |
| 5. Mercury ammonium chloride | 0 | 5 (7.14%) |
| 6. Fragrance mix I | 1 (3.70%) | 6 (8.57%) |
| 7. Colophonium | 1 (3.70%) | 2 (2.85%) |
| 8. Imidazolidinyl urea | 0 | 1 (1.42%) |
| 9. Clinquinol | 0 | 1 (1.42%) |
| 10. Myroxylon pereirae resin (Balsam Peru) | 2 (7.40%) | 4 (5.71%) |
| 11. IPPD | 2 (7.40%) | 0 |
| 12. Cobalt (II) chloride hexahydrate | 3 (11.11%) | 2 (2.85%) |
| 13. PTBP∗ | 4 (14.81%) | 0 |
| 14. Paraben mix | 1 (3.70%) | 0 |
| 15. Captan | 2 (7.40%) | 3 (4.28%) |
| 16. Budesonide | 0 | 2 (2.85%) |
| 17. Methylisothizolinone + methylcholoroisothizolinone | 0 | 1 (1.42%) |
| 18. Quaternium-15 | 1 (3.70%) | 0 |
| 19. MBT | 0 | 1 (1.42%) |
| 20. PPD | 0 | 7 (10%) |
| 21. Formaldehyde | 3 (11.11%) | 2 (2.85%) |
| 22. Mercapto mix | 1 (3.70%) | 1 (1.42%) |
| 23. Thimerosal | 4 (14.81%) | 5 (7.14%) |
| 24. Thiuram mix | 1 (3.70%) | 1 (1.42%) |
| 25. Tixocortol-21-pivalate | 0 | 1 (1.42%) |
IPPD, N-Isopropyl-N-pheynyl-4-phenylenediamine; MBT, 2-Mercaptobenzothiazole; PPD, p-phenylenediamine; PTBP, 4-tert-butylphenol-formaldehyde resin.
P value < .05.
These results would infer that the chemical components of disposable masks and residues of disinfectants or cosmetics can cause allergic and irritant reactions. Further, given the occlusive, humid environment within a facial mask, it can be assumed that these substances could more easily penetrate the skin and cause facial dermatitis.
Since the COVID-19 pandemic started, our living and medical environments have significantly changed, as have the frequency and types of exposure to allergens.4 , 5 Consequently, patch tests are essential for determining the correct diagnosis in patients with facial dermatitis. Our study could be a useful index for determining the causative allergens in patients with facial dermatitis induced by disposable masks.
Conflicts of interest
None disclosed.
Footnotes
Drs Kang and Chung contributed equally to this work.
Funding sources: This study was supported by grants from the National Research Foundation of Korea (2017R1A2B4006252, 2018R1C1B6007998) and the Korea Centers for Disease Control and Prevention (2020-ER6714-00).
IRB approval status: This study was approved by the Institutional Review Board of Hallym University Kangnam Sacred Heart Hospital (IRB No. 2020-10-016).
Reprints not available from the authors.
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