Canadian Journal of Infectious Diseases and Medical Microbiology
Volume 2018 (2018), Article ID 2563207, 4 pages
https://doi.org/10.1155/2018/2563207

Letter to the Editor

Response to: Comment on “Prevalence, Etiology, and Risk Factors of Tinea Pedis and Tinea Unguium in Tunisia”

Nourchène Toukabri,¹ Cyrine Dhieb,¹ Dalenda El Euch,² Mustapha Rouissi,³ Mourad Mokni,² and Najla Sadfi-Zouaoui¹

¹Laboratoire de Mycologie, Pathologies et Biomarqueurs, Faculté des Sciences de Tunis, Université Tunis El Manar, 2092 Tunis, Tunisia
²Service de Dermatologie et de Vénéréologie, Hôpital La Rabta, Tunis, Tunisia
³Institut National de la Recherche Agronomique de Tunis, Tunis, Tunisia

Correspondence should be addressed to Najla Sadfi-Zouaoui; sadfi.najla@gmail.com

Received 20 March 2018; Accepted 28 March 2018; Published 22 May 2018

Academic Editor: Maria L. Tornesello

Copyright © 2018 Nourchène Toukabri et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

We are grateful to Dr. Talel Badri [1] for his comments and suggestions on the article “Prevalence, Etiology, and Risk Factors of Tinea Pedis and Tinea Unguium in Tunisia” [2].

We have carefully looked at all the comments and earnestly hope that the provided responses will fulfill the concerns.

The statistical analysis of predisposing factors of foot mycosis using odds ratio and multivariate analysis “PCA-MCA” is explained in the following paragraph in accordance with Table 1.

Table 1: Odds ratio of predisposing factors affecting foot mycosis epidemiology.

Predisposing factors
Odds ratio
95% CI
value
Risk type

Sex
1.5635
0.7659 to 3.1916
0.2196
Absent

Ritual washing
0.7660
0.4058 to 1.4459
0.4108
Protector

Diabetes
0.8962
0.3579 to 2.2441
0.8149
Protector

Peripheral vascular disease
1.5683
0.6744 to 3.6467
0.2960
Absent

Autoimmune disease
5.1405
0.3045 to 86.7710
0.2562
Increase

Dermatological pathology
3.1878
0.1848 to 55.0016
0.4250
Increase

Obesity
2.3353
0.1326 to 41.1320
0.5623
Increase

Physical activities
0.4898
0.2379 to 1.0085
0.0527
Protector

Family history
0.6837
0.3596 to 1.2999
0.2461
Protector

Application of henna
0.7941
0.0935 to 6.7479
0.8328
Protector

Communal shower
0.8596
0.4637 to 1.5937
0.6311
Protector

Nail trauma
1.2677
0.6035 to 2.6628
0.5310
Absent

Wearing used shoes
15.702
2.1324 to 115.6224
0.0069
Increase

Season(a)
0.0425
0.0129 to 0.1398
0.0001
Protector

Psoriasis
1.7753
0.0984 to 32.0326
0.6973
Absent

Fungal infection of the skin
2.0545
0.1154 to 36.5672
0.6240
Increase

Occlusive shoes
14.391
0.8718 to 237.5528
0.0623
Increase

Swimming pools
8.3218
0.4995 to 138.6327
0.1398
Increase

Smoking
3.7646
0.2201 to 64.3923
0.3601
Increase

Walking barefoot
0.7220
0.2641 to 1.9737
0.5255
Protector

Pedicure
15.474
0.9382 to 255.2066
0.0554
Increase

Thermal station
0.4353
0.1767 to 1.0724
0.0706
Protector

Associated fingernail onychomycosis
0.5434
0.2109 to 1.4003
0.2066
Protector

Immunosuppressive drugs
0.8067
0.4118 to 1.5804
0.5313
Protector

Age (years)

1 to 10
0.1254
0.0245 to 0.6408
0.0126
Protector

11 to 20
0.3458
0.1184 to 1.0095
0.0521
Protector

21 to 30
0.6783
0.3082 to 1.4925
0.3346
Protector

31 to 40
0.9510
0.4373 to 2.0679
0.8991
Protector

41 to 50
2.4662
0.9429 to 6.4505
0.0658
Increase

51 to 60
1.1572
0.5349 to 2.5034
0.7107
Absent

61 to 70
1.0117
0.3768 to 2.7165
0.9816
Absent

>70
2.9077
0.3818 to 22.1439
0.3028
Absent

(a)Significance of “spring compared to other seasons (summer  +  autumn  +  winter).”

Statistical analysis was performed with SPSS software (Statistical Package for Social Sciences version 20.0, SPSS Inc., Armonk, NY). Odds ratio (OR) with 95% confidence interval (CI) was measured. The chi-square (χ²) was also used to calculate significant differences in characteristics between patients. Differences with were considered statistically significant. Multivariate analyses were carried out by two methods: principal components analysis (PCA) and multivariate correspondence analysis (MCA).

Table 1 shows results of odds ratio, 95% CI, and value; as a conclusion from Table 1, factors associated with foot mycosis such as sex, nail trauma, peripheral vascular disease, psoriasis, and age group over 51 do not present risk factors, whereas presence of dermatological pathology, obesity, wearing used shoes, occlusive shoes, smoking, attending swimming pools, making pedicure, and presence of fungal infection of the skin represent a risk factor of foot mycosis. However, practicing ritual washing, physical activities, attending communal shower, presence of family history, trauma of the nail, application of henna, walking barefoot, using thermal station, presence of associated fingernails, diabetes, and immunosuppressive therapy are protective factors.

Consequently, subjects especially between the age group 40 and 50 seem to be the most exposed to foot mycosis.

Multivariate analysis was carried out to determine the relationship between factors associated with foot mycosis. The correlation between factors, as shown in Table 2, discriminates factors highly related from those having a weak relationship with the infection.

Table 2: Correlation between factors associated with foot mycosis.

Ritual washing
0.751

Diabetes
0.927
0.452

Peripheral vascular disease
0.973
0.58
0.988

Dermatological pathology
0.887
0.363
0.995
0.969

Obesity
0.883
0.355
0.994
0.967
1.000

Physical activities
0.94
0.489
0.999
0.993
0.990
0.989

Family history of foot mycosis
0.994
0.687
0.959
0.989
0.926
0.923
0.970

Application of henna
0.880
0.351
0.994
0.966
1
1.000
0.988
0.921

Communal shower
0.858
0.983
0.607
0.718
0.526
0.519
0.639
0.807
0.515

Nail trauma
0.990
0.652
0.971
0.996
0.943
0.940
0.979
0.998
0.938
0.779

Wearing used shoes
0.991
0.668
0.958
0.989
0.928
0.925
0.964
0.991
0.922
0.792
0.995

Season
0.955
0.835
0.835
0.896
0.779
0.775
0.861
0.949
0.773
0.912
0.928
0.911

Psoriasis
0.88
0.35
0.994
0.966
1
1
0.988
0.921
1
0.514
0.938
0.923
0.772

Fungal infection of the skin
0.881
0.353
0.994
0.966
1
1
0.988
0.922
1
0.517
0.939
0.924
0.773
1

Occlusive shoes
0.933
0.464
0.999
0.991
0.993
0.992
0.997
0.961
0.991
0.618
0.974
0.965
0.833
0.991
0.992

Swimming pools
0.909
0.409
0.999
0.981
0.999
0.998
0.995
0.943
0.998
0.568
0.959
0.946
0.805
0.998
0.998
0.998

Smoking
0.889
0.368
0.996
0.971
1
1
0.990
0.928
1
0.531
0.945
0.93
0.782
1.000
1.000
0.994
0.999

Walking barefoot
0.909
0.412
0.999
0.981
0.999
0.998
0.996
0.945
0.998
0.57
0.959
0.944
0.812
0.998
0.998
0.997
1
0.999

Pedicure
0.938
0.474
0.999
0.992
0.992
0.991
0.997
0.964
0.990
0.627
0.977
0.968
0.838
0.990
0.990
1
0.997
0.992
0.996

Thermal station
0.905
0.404
0.998
0.978
0.999
0.998
0.995
0.942
0.998
0.563
0.956
0.94
0.81
0.998
0.998
0.996
0.999
0.999
1
0.995

Associated fingernails
0.906
0.406
0.999
0.979
0.999
0.998
0.996
0.943
0.998
0.565
0.957
0.942
0.81
0.998
0.998
0.997
0.999
0.999
1
0.996
1

Immunosuppressive drugs
0.988
0.646
0.973
0.996
0.946
0.943
0.982
0.998
0.942
0.773
1
0.992
0.931
0.941
0.942
0.975
0.961
0.947
0.962
0.978
0.959
0.960

Sex
Ritual washing
Diabetes
PVD
DP
Obesity
PA
FH
Application of henna
CS
Nail trauma
Wearing US
Season
psoriasis
Fungal IS
Occlusive Shoes
Swimming pools
Smoking
WB
Pedicure
Thermal station
AFO

Correlation is significant at 0.05; correlation is significant at 0.01; AFO: associated fingernail onychomycosis; CS: communal shower; DP: dermatological pathology; FH: family history; PA: physical activities; PVD: peripheral vascular disease; WB: walking barefoot.

For example, obesity is highly correlated to diabetes and peripheral vascular disease; however, wearing occlusive shoes is not correlated to ritual washing and attending communal shower.

As a result from this correlation matrix and the PCA (principal components analysis), factors are distributed as shown in Figure 1. From this illustration, we conclude that we have three groups of factors: most factors positively close to PC2 axis seem to be risk factors for foot mycosis, whereas most factors positively close to PC1 axis (sex, family history, wearing used shoes, nail trauma, immunosuppressive drugs, season, and peripheral vascular disease) seem to be with no risk; however, the group of factors negatively close to PC1 axis (physical activities, pedicure, occlusive shoes, diabetes, walking barefoot, swimming pools, smoking, thermal station, associated fingernail onychomycosis, dermatological pathology, obesity, fungal infection of the skin, psoriasis, application of henna, and autoimmune disease) are protectors from risk.

Figure 1: Principal components diagram of factors associated with foot mycosis.

We have also carried out a second multivariate analysis which is MCA (multiple correspondence analysis) in order to compare results of the two multivariate methods.

A plot illustrating eignvectors of factors associated with foot mycosis allows to discriminate between two essential groups: the first group gathering the sex, peripheral vascular disease, diabetes, and ritual washing, and the second including psoriasis, autoimmune disease, dermatological pathology, and obesity (Figure 2).

Figure 2: Multiple correspondence analysis of factors associated with foot mycosis.

From this work and depending on odds ratio analysis and the two multivariate methods used, we can conclude that we generally obtain the same groups of factors with some difference depending on the performance of methods.

It is true that there is a selection variation in our series. The clinical consultants are much more prone to suggest the mycological test in tinea unguium than tinea pedis because of the duration and the cost of treatment.

In order to respond to the last comment, we have a certitude explanation of nonsignificance of the two factors (ritual washing and communal shower), but it may be related to the improvement of hygiene in these facilities (mosques and hammams) and the individual behavior.

Conflicts of Interest

The authors declare that they have no conflicts of interest.

References

T. Badri, “Comment on “prevalence, etiology, and risk factors of tinea pedis and tinea unguium in Tunisia”,” Canadian Journal of Infectious Diseases and Medical Microbiology, vol. 2018, Article ID 4859514, 1 page, 2018.

N. Toukabri, C. Dhieb, D. El Euch, M. Rouissi, M. Mokni, and N. Sadfi-Zouaoui, “Prevalence, etiology, and risk factors of tinea pedis and tinea unguium in Tunisia,” Canadian Journal of Infectious Diseases and Medical Microbiology, vol. 2017, Article ID 6835725, 9 pages, 2017.