Abstract
Onychomycosis is one of the most common nail diseases in adults but is described as infrequent in children. Data are, however, scattered and diverse. Studies have nevertheless suggested that the prevalence of onychomycosis is increasing in children lately and the aim of this review was therefore to examine this problem. Two authors individually searched PubMed, Embase, and Cochrane Library for articles on epidemiology and prevalence of onychomycosis in children. The literature search was conducted in accordance per PRISMA guidelines. In total 1042 articles were identified of which 23 were eligible for inclusion. One of the articles presented two studies and a total of 24 studies were therefore included. Seventeen studies presented data of the prevalence of onychomycosis in children in the general population and seven studies among children visiting a dermatological and pediatric department or clinic. The prevalence ranged from 0% to 7.66% with an overall discrete increase of 0.66% during the period 1972 to 2014 in population studies (not statistically significant). This review supports a trend towards an increased prevalence of onychomycosis in children, albeit based on a paucity of studies. The data suggests an increasing prevalence of onychomycosis with age, and co‐infection with tinea pedis (reported in 25% of the studies). The most common pathogen reported was Trichophyton rubrum and onychomycosis was more prevalent in toenails compared to fingernails. The general characteristics of onychomycosis in children are thus similar to those described in adults.
Keywords: child, onychomycosis, prevalence, systematic review, tinea
1. INTRODUCTION
Fungal infection of the nails accounts for 15%–40% of all nail disease and is one of the most common nail diseases in adults. The prevalence of onychomycosis increases with age and is reported to be infrequent in children. 1 It has nevertheless been suggested that the incidence of onychomycosis in children may have increased over the last three decades. 2 , 3 , 4 However, most studies are retrospective and based on information from medical records or laboratory data. 2 , 3 , 4
Pediatric onychomycosis is important to diagnose and treat for several reasons. Early detection and treatment of onychomycosis is crucial to prevent disease progression. 1 In addition, early treatment of onychomycosis can result in higher cure rates. Mild onychomycosis can be treated topically with good clearance in children. Few antifungal therapies are licensed to onychomycosis treatment in children. Topical therapy is used as monotherapy for milder cases and is approved by the United States Food and Drug Administration (FDA) from the age of ≥12 years (ciclopirox), and ≥6 years (efinaconazole, tavaborole). Treatment with topical therapy is reported to be more effective in children than in adults, 5 with low risk of side effects and low systemic exposure. Systemic treatment is added when the disease is more severe but has a larger risk of drug interaction and adverse events. No systemic antifungal therapy is licensed for treatment of onychomycosis in children. 5
The aim of this systematic review is to explore the worldwide prevalence of onychomycosis in children.
2. MATERIALS AND METHODS
This systematic review focus on the prevalence of onychomycosis in children (0–18 years) and it is reported in accordance with the PRISMA guidelines. 6 The systematic review was registered at PROSPERO April 11, 2021 with the registration number CRD42021241810. Details of the protocol can be accessed at www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021241810.
The databases PubMed, Embase, and Cochrane Library were searched for articles on March 11, 2021. Two authors (SVJ & AM) conducted the search independently using the literature search tool Rayyan. 7 In case of disagreement the senior author (DMS) was consulted.
The final search string is available in Appendix A.
2.1. Inclusion criteria
Studies reporting prevalence of onychomycosis in children published in a peer reviewed journal in English or Danish language. Only studies with 100 or more children (<18 years) were included.
2.2. Exclusion criteria
Studies with special patient groups (e.g., diabetes and immunodeficiency) and studies where the whole study population had or was suspected of having onychomycosis or a superficial mycosis before entering the study were excluded. Studies focusing on a specific etiological agent or laboratory surveys of specimens from patients with suspected onychomycosis were also excluded.
Details of the literature search and screening of the articles are available in Figure 1.
FIGURE 1.
PRISMA Flow Diagram 2020. 6 Reason 1: Cohort of patients with a superficial mycosis or suspected onychomycosis (n = 64), Reason 2: Not enough data on children (n = 21), Reason 3: Wrong publication type (n = 9), Reason 4: Wrong population (n = 3), Reason 5: <100 children included (n = 2), Reason 6: Diagnosis method not available or specified (n = 2), Reason 7: Included in another study (n = 1)
2.3. Data collection and statistic
Data on the prevalence of onychomycosis, publication year, country, the type and size of the study population, diagnostic method, prevalence of onychomycosis in fingernails compared with toenails, risk factors, etiological agents, concomitant mycosis, or skin disease were extracted by one researcher (SVJ) to a predesigned Excel sheet. The data were reported as a narrative synthesis. Meta‐analysis could not be made because of heterogeneity of the study designs. Linear regression was fitted to the data for prevalence of onychomycosis in children in percent (%) as a function of time, using the program RStudio Version 1.2.1335 (RStudio ©, Boston) to ascertain if the variable time could explain the change in prevalence.
3. RESULTS
3.1. Literature search
A total of 1042 articles were identified by searching Embase, PubMed, and Cochrane library of which 237 articles were duplicates and 805 were screened. Of these, 680 were out of scope, and 125 articles were read. In total 23 articles were included in the review (Figure 1). The 23 articles with 24 studies were conducted over a period of 44 years. A total of 17 studies explored the prevalence of onychomycosis in the general population (Table 1), whereas seven studies investigated the prevalence of onychomycosis among children which were attending a pediatric or dermatological clinic or department (Table 2). In population‐based studies, the prevalence of onychomycosis in children ranged from 0% to 3.37% and in studies from pediatric or dermatological clinics or departments the prevalence varied from 0% to 0.53% (prevalence from studies that used clinical observation, microscopy, and culture as diagnostic method).
TABLE 1.
Studies on the prevalence of onychomycosis in children in the background population
| [Ref.] | Country, publication year(ref) | Study cohort | Children/total | Male % of total children | Age range (years) | Diagnostic method | Prevalence (number of cases/total) | Etiological agents (n, %) |
|---|---|---|---|---|---|---|---|---|
| 17 | India, 1972 17 | School | 440/440 | 69.1% | 5–16 | CL + M + C |
0.22% (1/440) |
NA |
| 23 | Mexico, 2003 23 | School | 133/133 | 79.0% | 7–18 | CL + M + C |
0.75% (1/133) |
T. mentagrophytes (1, 100%) |
| 28 | Solomon Islands, 1985 28 | Population a | 5160/10,224 | NA | 0–14 | CL |
7.66% (395/5160) |
NA |
| 18 | UK, 1989 18 | Primary schools | 494/494 | NA | 5–10 | CL + M + C |
0.20% (1/494) |
T. rubrum (1, 100%) |
| 19 | Finland, 1995 19 | Schools | 100/800 | 48% | 6–10 | CL + M + C |
0% (0/100) |
NA |
| 24 | Turkey, 2002 24 | Primary schools | 785/785 | 56.1% |
6–14 Mean: 9.25 ± 1.55 |
CL + M c |
0.25% (2/785) |
NA |
| 11 | Turkey, 2004 11 | Residents of the rural region of Duzce | 109/227 | NA | 0–14 | CL + M + C |
0% (0/109) |
NA |
| 26 | Turkey, 2005 26 | Boarding school | 166/682 | 100% | 14–16 | CL + M |
0% (0/166) |
NA |
| 9 | Turkey, 2006 9 | Schools | 7158/7158 | 52.6% | 6–14 | CL + M + C |
0.15% b (11/7158) |
C. albicans (5, 45.5%) C. glabrata (5, 45.5%) C. tropicalis (1, 9.0%) |
| 10 | Turkey, 2006 10 | Primary schools | 23,235/23,235 | 54.5% b |
7–14 Mean: 9.72 ± 1.06 |
CL + M + C |
0.10% (24/23,235) |
Trichosporon spp. (11, 45.8%) T. rubrum (6, 25%) C. albicans (5, 20.8%) C. glabrata (2, 8.3%) |
| 13 | Israel, 2009 13 | Primary schools | 1148/1148 | 52.1% | 5–14 | CL + M + C |
0.87% (10/1148) |
T. rubrum (7, 70%) T. mentagrophytes (2, 20%) C. albicans (1, 10%) |
| 14 | Peru, 2009 14 | Schools | 1361/1361 | NA | 12–17 | CL + M + C |
3.37% (46/1361) |
NA |
| 12 | Spain, 2009 12 | Schools | 1305/1305 | 50.1% | 3–15 | CL + M + C |
0.15% (2/1305) |
T. rubrum and T. tonsurans (2, 100%) |
| 27 | Ethiopia, 2010 27 | Primary schools | 382/1104 | NA | 7–12 | CL |
7.59% (29/382) |
NA |
| 8 | Turkey, 2013 8 | Primary schools | 8122/8122 | 49.6% |
5–16 Mean: 10.61 ± 2.41 |
CL + M + C |
0.33% (27/8122) |
T. rubrum (12, 44.4%) T. mentagrophytes (1, 3.7%) T. tonsurans (1, 3.7%) T. spp. (3, 11.1%) C. glabrata (4, 14.8%) C. parapsilosis (1, 3.7%) Trichosporon spp. (2, 7.4%) Rhodotorula spp. (3, 11.1%) |
| 29 | Egypt, 2014 29 | Primary schools | 6162/6162 | 44.8% | 6–12 | CL |
0.03% (2/6162) |
NA |
| 15 | Nigeria, 2014 15 | Schools | 800/800 | 51% |
5–16 Mean: 9.42 ± 2.00 |
CL + M + C |
0.88% b (7/800) |
T. rubrum (2, 28.6%) E. floccosum (5, 71.4%) |
Abbreviations: C., Candida; C, culture; CL, clinical; E., Epidermophyton; M, microscopy; NA, not available; OM, onychomycosis; SFI, superficial fungal infection; T., Trichophyton; spp., species.
Screening in combination with a treatment campaign for Yaws.
Calculation based on data extracted from the article.
C was performed but contaminated.
TABLE 2.
Studies on the prevalence of onychomycosis in children in hospitals and clinics
| [Ref.] | Country, publication year(ref) | Study cohort | Children/total | Male % of total children | Age range (years) | Number referred with SFI or OM | Diagnostic method | Prevalence (number of cases/total) | Etiological agents (n, %) |
|---|---|---|---|---|---|---|---|---|---|
| 18 | UK, 1989 18 | Pediatric out‐patient clinic | 200/200 | NA | 3–12 |
OM: 0 SFI: 0 |
CL + M + C |
0% (0/200) |
NA |
| 20 | North America (Canada & USA), 1997 20 | Dermatology centers and GP | 2500/2500 | 44.7% | 0–18 Mean: 1.2 ± 0.1 years |
SFI:NA OM: 7 |
CL + M + C |
0.44% (11/2500) |
T. rubrum (8, 72.7%) T. rubrum and E. floccosum (1, 9.1%) M positive only: (2, 18.2%) |
| 21 | USA, 1997 21 | Dermatology department | 189/1038 | NA | 0–18 |
OM: 0 SFI: All cases of tinea pedis excluded. Other SFI: NA |
CL + M + C |
0.53% (1/189) |
NA |
| 25 | Canada, 1997 25 | Dermatology offices | 126/2001 | 54.8% | 0–10 |
OM: 0 SFI: 17 with Tinea pedis |
CL+ M b |
0% (0/126) |
NA |
| 22 | Belgium, the Czech Republic, Germany, Great Britain, Greece, Hungary and Luxembourg, 1999 22 | Dermatology centers | 1613/13,486 | NA | <18 |
OM and SFI: NA Patients, who presented with any dermatological disorder included |
CL + M or CL+ C (either or both positive) | 0.19% (3/1613) | NA |
| 30 | Brazil, 2013 30 | Dermatology office | 718/7687 | NA | 0–17 |
OM: NA SFI: NA |
CL |
5.01% a (36/718) |
NA |
| 16 | Canada, 2016 16 | Dermatology centers and GP | 2783/32,193 | 49.4% | 0–9 |
OM: 0 SFI: NA |
CL + C c |
0.29% (8/2783) |
NA |
Abbreviations: C., Candida; C, culture; CL, clinical; E., Epidermophyton; GP, general practitioner office; M, microscopy; NA, not available; OM, onychomycosis; SFI, superficial fungal infection; T., Trichophyton.
Calculation based on data extracted from the article.
M positive was used as the definition of onychomycosis. C was also performed, but patients with negative C and positive M were also defined as having onychomycosis.
C positive was used as the definition of onychomycosis. M was also performed, but either M positive or negative with C positive was included.
The number of children included in the studies ranged from 100 to 32,235 children, and the majority of the included children were in the age range from 5 to 16 years in population‐based studies and 0 to 18 years in dermatological clinics or departments, respectively.
3.2. Demographic data
Two studies showed an association between an increase in prevalence of onychomycosis and increasing age in children. 8 , 9 Unfortunately, separate details on age and onychomycosis were not available to allow further analysis.
For the studies that provided sex data, the frequency of males ranged from 44.7% to 100%, and the mean prevalence of males in the included studies was 51.9% (28,507 male children/65,189 children). It was not possible to extract the exact male frequency of onychomycosis, but one study found that boys were more likely to have onychomycosis than girls (p = 0.001, male frequency: 54.5%). 10
3.3. Diagnostic work‐up
All studies reported on clinical diagnosis (nail changes) and most studied confirmed the clinical suspicion of onychomycosis with microscopy in combination with culture (17/24). 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 The prevalence of onychomycosis in studies using a combination of clinical diagnosis, microscopy and culture ranged from 0 to 3.37%. 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23
Three studies relied on clinical diagnosis and microscopy only with prevalence rates ranging from 0 to 0.25%. 24 , 25 , 26
Three studies relied on clinical diagnose only. 27 , 28 , 29 One study reported that only half of the cases had a mycological confirmation of onychomycosis, all cases were therefore reported as diagnosed clinically. 30 Prevalence rates in studies relying primarily on clinical diagnosis ranged from 0.03% to 7.66% 27 , 28 , 29 , 30 and of those, three reported the highest prevalence rates in the current review (7.66% from 1985 Solomon Islands, 28 7.59% 2010 Ethiopia, and 5.01% from 2013 Brazil 30 respectively).
3.4. Distribution over time
Figure 2A illustrates the prevalence of onychomycosis over time in 12 population‐based studies and five studies from dermatology clinics and departments diagnosed clinically and with culture and microscopy. The studies were published during the years 1972–2016 and the prevalence increased from 0.22% in 1972 17 to between 0.29% and 0.88% in 2014–16. 15 , 16
FIGURE 2.
Prevalence of onychomycosis in children in population studies (blue) and studies from pediatric or dermatological clinics or departments (orange diagnosed by clinical observation, microscopy, and culture). Notice an outlier data point (prevalence of 3.37% 14 )
When focusing on the prevalence of childhood onychomycosis in Turkey only, this review identified six studies published during the years 2002–2013. 8 , 9 , 10 , 11 , 24 , 26 The prevalence of onychomycosis among Turkish children ranged from 0% to 0.33% and showed a small increase in prevalence from 2004 to 2013. 8 , 11
3.5. Geographical distribution
The geographical distribution is presented in Figure 3. The included studies from dermatology clinics, departments and hospitals originate from South America (Brazil), North America (Canada and USA), Europe (UK and a co‐operative study [the Achilles project] performed in Belgium, the Czech Republic, Germany, Great Britain, Greece, Hungary, and Luxembourg). The population studies were executed in Western Asia (Turkey, Egypt, Israel), Oceania (the Solomon Islands), East Africa (Ethiopia), South America (Peru), Europe (Spain, UK, Finland), West Africa (Nigeria), South Asia (India), and North America (Mexico).
FIGURE 3.
The worldwide prevalence of onychomycoses. Prevalence for each study shown in %. M: microscopy; C: culture; Cl: clinical. In a joined study of Belgium, The Czech Republic, Germany, Great Britain, Greece, Hungary and Luxembourg the prevalence was 0.19% 22
The highest prevalence of onychomycosis in children diagnosed mycologically was 3.37% in a study from 2009 from Peru. 14 This prevalence was much higher than what similar studies using the same diagnostic methods from other countries reported 0%–0.88%. 8 , 9 , 10 , 11 , 12 , 13 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 23 Besides the prevalence from Peru, the highest prevalences, diagnosed clinically and with microscopy and culture, were from Mexico 0.75%, 23 Israel 0.87% 13 and Nigeria 0.88%. 15 In studies with clinical diagnosis only (without mycological confirmation) the prevalence is generally higher and up to 7.59% in Ethiopia 27 and 7.66% from 1985 Solomon Islands. 28
The prevalence of mycologically confirmed onychomycosis in Europe ranged from 0% to 0.20%, 12 , 18 , 19 , 31 in North America from 0% to 0.75%, 16 , 20 , 21 , 23 , 25 and in West Asia from 0% to 0.87%. 8 , 9 , 10 , 11 , 13 , 24 , 26 See Tables 2 and 3 for details of the five studies from other geographical regions. 17 , 27 , 28 , 29 , 30
TABLE 3.
Studies with data on the distribution of onychomycosis in toenails and fingernails
| [Ref.] | Country, publication year(ref) | Study cohort | Children/total | Male % of total children | Age range (years) | Prevalence (number of cases/total) | Cases with toenails affected (n, %) |
|---|---|---|---|---|---|---|---|
| 20 | North America (Canada + USA), 1997 20 | Dermatology centers and GP | 2500/2500 | 44.7% | 0–18 Mean: 1.2 ± 0.1 years |
0.44% (11/2500) |
(10, 91%) |
| 9 | Turkey, 2006 9 | Schools | 7158/7158 | 52.6% | 6–14 |
0.15% a (11/7158) |
(7, 64%) |
| 10 | Turkey, 2006 10 | Primary schools | 23,235/23,235 | 54.5% a |
7–14 Mean: 9.72 ± 1.06 |
0.10% (24/23,235) |
(24, 100%) |
| 14 | Peru, 2009 14 | Schools | 1361/1361 | NA | 12–17 |
3.37% (46/1361) |
(40, 87%) |
| 8 | Turkey, 2013 8 | Primary schools | 8122/8122 | 49.6% |
5–16 Mean: 10.61 ± 2.41 |
0.33% (27/8122) |
(27, 100%) |
| 15 | Nigeria, 2014 15 | Schools | 800/800 | 51% |
5–16 Mean: 9.42 ± 2.00 |
0.88% a (7/800) |
(1, 14%) |
Note: All studies used clinical observation, microscopy and culture as diagnostic methods.
Calculation based on data extracted from the article.
3.6. Onychomycosis with concomitant skin infections
A total of seven studies reported on co‐infection on other body sites (tinea pedis [6/105] 8 , 9 , 12 , 14 , 20 , 23 or tinea capitis [1/105]). 15 In two studies no concomitant mycosis was found, 18 , 24 and in one study no concomitant tinea pedis was found. 10
3.7. Fungal pathogens
Dermatophytes (55/95) were more common than yeast (40/95) and the most prevalent dermatophyte species were T. rubrum (39/55), T. mentagrophytes (4/55) including a co‐infection with T. tonsurans and E. floccosum (3/55). The most common yeasts isolated were C. albicans (11/40) and C. glabrata (11/40). The only study that specified the isolates from fingernails reported C. albicans (1/4), C. glabrata (2/4) and C. tropicalis (1/4) in four patients. 9 Trichosporon spp. (n = 13/40) were isolated in two studies from Turkey. 8 , 10
3.8. Prevalence of onychomycosis in fingernails compared to toenails
The distribution of onychomycosis infecting fingernails compared to toenails was examined in six studies. 8 , 9 , 10 , 14 , 15 , 20 The prevalence of onychomycosis in toenails ranged from 0.10% to 2.94%, and in fingernails from 0% to 0.75%. In five studies 8 , 9 , 10 , 14 , 20 onychomycosis was more prevalent in the toenails than the fingernails, and in one study it was more prevalent in fingernails. 15 In six studies only toenails were examined. 12 , 13 , 16 , 22 , 23 , 24 The details of the studies can be seen in Table 3.
4. DISCUSSION
This systematic review supports the hypothesis of a generally increasing prevalence of onychomycosis in children especially during the years 2000–2015 (Figure 2).
Estimated prevalence rates are based on diagnosing onychomycosis in a given sample. Diagnostic accuracy in the pediatric population is of the outmost importance as only about 15.5% of nail dystrophies in children are caused by onychomycosis. 32 The majority of the studies 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 (83% [20/24] see Table 1) confirmed the clinical suspicion of onychomycosis by mycological examination.
The data appear independent of the sampling method in spite of great variation in the number or sex of the participants, cultural differences such as type of footwear, sport activities etc. which may all impact the prevalence.
We expected to find a higher prevalence rate of onychomycosis in dermatology centers and clinics than in the background population, 33 represented by the studies carried out at schools and in the general population, but this hypothesis remains un‐supported (Table 1 compared to Table 2). This lack of difference in prevalence rates might be influenced by the difference in age groups examined, where most of the studies from hospitals and clinics included younger children aged 0–4 years (6/7), 16 , 20 , 21 , 22 , 25 , 30 while most of the studies from the background population (14/17) included older school children. 8 , 9 , 10 , 13 , 14 , 15 , 17 , 18 , 19 , 23 , 24 , 26 , 27 , 29
Furthermore, geography may play a role, as a higher prevalence occurs in warmer countries, see Figure 3. The analysis does however not allow us to adjust the data for possible confounders such as footwear, access to health care and similar factors that may all influence the result.
Topographically, onychomycosis is generally more prevalent in toenails than fingernails in children and adults alike. 1 Transfer apparently occurs when tinea pedis spread to the toenails, which has also been described in adult studies. 34 This could correlate with the six studies where concomitant tinea pedis and onychomycosis were found. 8 , 9 , 12 , 14 , 20 , 23
The dermatophyte, T. rubrum was the most prevalent pathogen identified (39/153), 36% of the total cases confirmed with culture, which is in good agreement with previous studies in adults. 1 , 33 Yeasts accounted for 26% (40/153) of the infections, represented by the Trichosporon spp. (13/40), C. albicans (11/40), C. glabrata (11/40), Rhodotorula spp. (3/40), C. parapsilosis (1/40), C. tropicalis (1/40) primarily isolated in Turkish studies. 8 , 9 , 10
Onychomycosis caused by yeasts is more prevalent in the fingernails than toenails and is also more prevalent in the immunosuppressed and in neonates. 1 , 35 It is therefore interesting that most cases of onychomycosis caused by yeasts were found in toenails (35/39) of supposedly healthy school children in the Turkish studies. 8 , 9 , 10 An exploration of associated factors as, for example, moist shoe environment, genetic predisposition, odiabetes would be of interest.
In 38% of the cases, the species of fungus were not determined in children. Additional limitations to our results are the population size limit of minimum 100 children, a difference in age groups between children seen at dermatology centers and clinics (younger) compared with children from background populations (mainly older school children) and lack of testing for yeast and non‐dermatophyte molds but also the prevalence of familial disease as an indicator of both higher exposure as well as genetic predisposition. All studies with a prevalence of 0% (5/5) had study populations of 100–200 children. 11 , 18 , 19 , 25 , 26 This indicates that the limit of at least 100 children in the study population should have been set above 200 instead. Only three studies examined children in the age range from 0–18 years old 20 , 21 , 22 while the other studies had a more narrow age range. In studies from hospitals and clinics most (6/7) of the included children aged 0–4 years old up to 18 years. 16 , 20 , 21 , 22 , 25 , 30 (Table 2) However most of the background population studies (14/17) only included school children (Table 1). 8 , 9 , 10 , 13 , 14 , 15 , 17 , 18 , 19 , 23 , 24 , 26 , 27 , 29
Nine of the studies only investigated for dermatophytes (and C. albicans), 12 , 13 , 15 , 17 , 18 , 19 , 20 , 21 and the prevalence of onychomycosis from other pathogens such as non‐albicans yeasts and non‐dermatophyte molds were not included.
5. CONCLUSION
In conclusion, the systematic review suggests a trend of an increasing prevalence of onychomycosis in children however this trend is not statistically significant based on available data. Childhood onychomycosis has many similarities with adult onychomycosis; it should be considered when the child presents with tinea pedis. The most prevalent pathogen is T. rubrum and toenail infection is more prevalent as compared to fingernails.
FUNDING INFORMATION
This research did not receive any grant from funding agencies in the public, commercial, or not‐for‐profit sectors.
CONFLICT OF INTEREST
DM Saunte received honoraria as a consultant for advisory board meetings by AbbVie, Janssen, Sanofi, LeoPharma, Novartis and as a speaker and/or received grants from the following companies: Abbvie, Janssen, Novartis, Sanofi and Leo Pharma during the last 3 years. She is a primary investigator for Leopharma. GBE Jemec has received honoraria from AbbVie, Chemocentryx, Coloplast, Incyte, Inflarx, Novartis, Pierre Fabre and UCB for participation on advisory boards, and grants from Abbvie, Astra‐Zeneca, Inflarx, Janssen‐Cilag, Leo Pharma, Novartis, Regeneron and Sanofi, for participation as an investigator, and received speaker honoraria from AbbVie, Boehringer‐Ingelheim, Galderma and MSD. He has also received unrestricted departmental grants from Abbvie, Leo Pharma and Novartis. S. Vestergaard‐Jensen, A. Mansouri, L.H. Jensen declare no conflicts of interest.
ACKNOWLEDGMENTS
The authors would like to thank and express our appreciation to Pernille Lindsø Andersen for the statistical analysis.
APPENDIX A.
| Database | Search | Search string | Number of results |
|---|---|---|---|
|
PubMed Date: 11 March 2021 |
#1 | (((((((“Onychomycosis”[Mesh]) OR (onychomycos*)) OR ((“nail*”[All Fields] AND “fung*”[All Fields]) OR “nail* fung*”[All Fields])) OR (((“Tinea”[MeSH Terms] OR “Tinea”[All Fields]) AND “unguium”[All Fields]) OR “tinea unguium”[All Fields])) OR ((“candidiasis”[MeSH Terms] OR “candidias*”[All Fields]) AND “unguium”[All Fields])) OR ((“nail*”[All Fields] AND “mycos*”[All Fields]) OR “nail* mycos*”[All Fields])) AND ((((((((((((((“Child”[Mesh]) OR (Child*)) OR (kid)) OR ((“paediatrics”[All Fields] OR “pediatrics”[MeSH Terms] OR “pediatrics”[All Fields] OR “paediatric”[All Fields] OR “pediatric”[All Fields]) AND “patient*”[All Fields])) OR (“infant, newborn”[MeSH Terms] OR (“infant”[All Fields] AND “newborn”[All Fields]) OR “newborn infant”[All Fields] OR “baby”[All Fields])) OR (infant*)) OR (“Infant”[Mesh])) OR (toddler*)) OR (“Adolescent”[Mesh])) OR (adolescent*)) OR (teenager*)) OR (youth*)) OR (“babies”[All Fields])) OR (“kids” [All Fields]))) AND ((((((((((((“Cohort Studies”[Mesh]) OR ((“cohort*”[All Fields] AND “study”[All Fields]) OR (“cohort*”[All Fields] AND “studies”[All Fields]) OR “cohort study”[All Fields] OR “cohort studies”[All Fields])) OR ((“cohort*”[All Fields] AND “analys*”[All Fields]) OR “cohort* analys*”[All Fields])) OR (“Cross‐Sectional Studies”[Mesh])) OR ((“cross‐sectional*”[All Fields] AND “study”[All Fields]) OR (“cross‐sectional*”[All Fields] AND “studies”[All Fields]) OR “cross‐sectional study”[All Fields] OR “cross‐sectional studies”[All Fields])) OR ((“cross‐sectional*”[All Fields] AND “analys*”[All Fields]) OR “cross‐sectional* analys*”[All Fields])) OR (“Epidemiologic Studies”[Mesh])) OR (“Epidemiology”[Mesh])) OR (“Observational Studies as Topic”[Mesh])) OR (“epidemiolog*”[All Fields])) OR ((“epidemiolog*”[All Fields] AND “study”[All Fields]) OR (“epidemiolog*”[All Fields] AND “studies”[All Fields]) OR “epidemiologic study”[All Fields] OR “epidemiologic studies”[All Fields] OR “epidemiological study”[All Fields] OR “epidemiological studies”[All Fields])) OR ((“observational*”[All Fields] AND “study”[All Fields]) OR (“observational*”[All Fields] AND “studies”[All Fields]) OR “observational study”[All Fields] OR “observational studies”[All Fields])) | 575 |
|
Embase Date: 11 March 2021 |
#2 | exp onychomycosis/ | 6683 |
| #3 | (onychomycos* or tinea unguium or candidiasis unguium).mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 7333 | |
| #4 | (fungal infection* adj2 nail*).mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 106 | |
| #5 | (nail* adj2 fung*).mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 471 | |
| #6 | (nail* adj2 mycos*).mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 75 | |
| #7 | 1 or 2 or 3 or 4 or 5 | 7428 | |
| #8 | exp child/ | 2,716,671 | |
| #9 | exp pediatric patient/ | 22,020 | |
| #10 | exp infant/ | 1,017,000 | |
| #11 | exp adolescent/ | 1,575,836 | |
| #12 | exp juvenile/ | 3,563,608 | |
| #13 | (child* or kid or kids or baby or babies or infant*).mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 3,184,225 | |
| #14 | (pediatric* adj2 patient*).mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 120,883 | |
| #15 | (pediatric* adj2 patient*).mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 20,220 | |
| #16 | (toddler* or adolescent* or teenager* or youth*).mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 1,706,051 | |
| #17 | 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 | 4,262,599 | |
| #18 | Exp epidemiology/ | 3,652,150 | |
| #19 | Exp observational study/ | 225,626 | |
| #20 | Epidemiology.mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 1,413,597 | |
| #21 | (epidemiologic* adj2 study).mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 32,991 | |
| #22 | (epidemiologic* adj2 studies).mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 89,765 | |
| #23 | (observational adj2 study).mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 279,405 | |
| #24 | (observational adj2 studies).mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 47,527 | |
| #25 | exp cross‐sectional study/ | 398,929 | |
| #26 | (Cohort* adj2 study).mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 341,667 | |
| #27 | (cohort* adj2 studies).mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 43,758 | |
| #28 | (cohort adj2 analys*).mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 688,397 | |
| #29 | (cross‐sectional adj2 study).mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 456,780 | |
| #30 | (cross‐sectional adj2 studies).mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 18,275 | |
| #31 | (cross‐sectional adj2 analys*).mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word] | 18,391 | |
| #32 | 17 or 18 or 19 or 20 or 21 or 22 or 23 or 24 or 25 or 26 or 27 or 28 or 29 or 30 | 4,889,436 | |
| #33 | 6 and 16 and 31 | 467 |
Vestergaard‐Jensen S, Mansouri A, Jensen LH, Jemec GBE, Saunte DML. Systematic review of the prevalence of onychomycosis in children. Pediatr Dermatol. 2022;39(6):855‐865. doi: 10.1111/pde.15100
DATA AVAILABILITY STATEMENT
Data sharing is not applicable to this article as no new data were created or analyzed in this study.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
Data sharing is not applicable to this article as no new data were created or analyzed in this study.