## Superficial fungal infections
Superficial fungal infections (SFIs), also known as superficial mycoses, are common, benign infections affecting the skin, hair, scalp, or nails caused by fungi. Dermatophytes, fungi that feed on keratin in the skin, are the main culprits, but other fungi such as non-dermatophyte molds and some yeasts can also cause these infections, sometimes simultaneously.
The World Health Organization estimates that SFIs affect about 25% of the global population. (1)
## Causes and transmission
SFIs are transmitted mainly through three routes: human contact, animal contact, and environmental exposure.
### Human transmission
– Direct contact with an infected person
– Contact with objects contaminated by an infected person (e.g., yoga mats, towels, sandals)
– Contact with contaminated surfaces such as shower floors or public pools
### Animal transmission (zoophilic)
– Direct contact with infected animals, including pets like dogs and cats
### Soil transmission (geophilic)
– Direct contact with contaminated soil, for example during gardening
### Risk factors
Certain conditions increase susceptibility to SFIs:
– Humid and warm environments
– Skin injuries or sores
– Poor or excessive hygiene
– Chronic illnesses such as diabetes or poor circulation
– Immunosuppression
– Use of antibiotics or corticosteroids
## Common symptoms
Symptoms vary depending on the infection site and the fungal species involved.
### Nails (nail fungus or onychomycosis)
– White or yellowish spots on nails
– Thickened, deformed nails that may detach, typically without pain or itching (3)
### Feet (athlete’s foot)
– Itching and burning sensations
– Cracked, scaly skin often located between the third and fourth toes (5)
## Diagnosing SFIs using molecular analysis
A qualified professional collects skin or nail samples for molecular analysis, which can detect over 50 types of fungi simultaneously, including dermatophytes, yeasts, and molds, even in mixed infections.
Molecular DNA detection performed in accredited laboratories identifies the exact fungal species causing the infection quickly and with high precision.
## Advantages of molecular analysis
### More precise diagnosis
SFIs share symptoms with other skin conditions like psoriasis, eczema, autoimmune diseases, bacterial infections, and tumors, making diagnosis challenging. Molecular analysis’s sensitivity and specificity allow confirmation or exclusion of fungal infections, facilitating appropriate treatment and helping identify infection sources to prevent reinfections.
### Detection of mixed infections
Mixed infections, especially involving non-dermatophyte molds, are harder to treat and have higher recurrence rates. Molecular analysis can detect multiple pathogens from a single sample, improving treatment success.
### Reliability
This method detects more than 50 types of fungi, including those difficult or impossible to identify by traditional culturing or microscopy.
### Fast results
Results are available within 7 days, much faster than the 4 weeks or more needed for culture-based methods.
### Specific and reliable diagnosis for treatment
These services assist podiatrists in diagnosing nail and skin SFIs accurately and determining the appropriate treatment.
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### References
1. Sai BS, Tejashree A, Veeranna S, Krishna Karthik M. Speciation and in vitro activity of four antifungal drugs against clinical isolates of dermatophytes by E-test method. *Int J Sci Res.* 2019;8.
2. Ameli. Available [in French only] from: https://www.ameli.fr/assure/sante/themes/mycose-cutanee-peau/prevention.
3. Chris G. Adigun. *Merck Manual*. Available from: https://www.merckmanuals.com/en-ca/home/skin-disorders/nail-disorders/onychomycosis.
4. [in French only] https://publications.msss.gouv.qc.ca/msss/fichiers/guide-garderie/chap7-tinea-capitis.pdf.
5. https://www.msdmanuals.com/fr/accueil/troubles-cutan%C3%A9s/infections-mycosiques-de-la-peau/pied-d%E2%80%99athl%C3%A8te-tinea-pedis.
6. [in French only] https://dermato-info.fr/fr/les-maladies-de-la-peau/les-mycoses-cutan%C3%A9es#mycose_description.
7. Salakshna N, Bunyaratavej S, Matthapan L, Lertrujiwanit K, Leeyaphan C. A cohort study of risk factors, clinical presentations and outcomes for dermatophyte, nondermatophyte, and mixed toenail infections. *J Am Acad Dermatol.* 2018;79:1145–1146.
8. Antuori A, Fernández G, Fernández A, Alcaide M, Boada A, Bielsa MI, Romaní N, Matas L. Epidemiology of dermatophytic infections between 2008 and 2017 in Barcelona, Spain. *Enferm Infecc Microbiol Clin.* 2019;37:642–647.
9. https://cps.ca/en/documents/position/antifungal-agents-common-infections.
10. Salakshna N, Bunyaratavej S, Matthapan L, Lertrujiwanit K, Leeyaphan C. A cohort study of risk factors, clinical presentations and outcomes for dermatophyte, nondermatophyte, and mixed toenail infections. *J Am Acad Dermatol.* 2018;79:1145–1146.