At Kin Body and Sole Podiatry Clinic, we regularly see patients concerned about changes to their toenails, such as thickening, discolouration, or lifting. These symptoms are often assumed to be fungal; however not all nail conditions are caused by fungal infection.
Accurate diagnosis is essential to ensure the most effective treatment, and this is where dermatophyte testing plays an important role.
What Are Fungal Nails?
Fungal nail infections (onychomycosis) are caused by fungi such as dermatophytes, yeasts, and moulds. They are one of the most common nail conditions worldwide and can impact both appearance and comfort (Gupta et al., 2022; Wongyikul et al., 2026).
Common signs include:
- Yellow, white, or brown discolouration
- Thickened or brittle nails
- Crumbling edges
- Separation from the nail bed (onycholysis)
However, these features are not specific to fungal infections, which means visual diagnosis alone is not always reliable.
Why Dermatophyte Testing Is Important
At Kin Body and Sole, we follow evidence based practice and recommend dermatophyte testing where appropriate before beginning treatment.
1. Confirms the Diagnosis
Research shows that only around 59% of nails diagnosed clinically as fungal are confirmed by laboratory testing (Gupta et al., 2024).
2. Prevents Unnecessary Treatment
Fungal nail treatments—particularly oral antifungal medications—can be long and may carry risks. Clinical guidelines recommend confirmatory testing before initiating treatment, especially oral therapy (Frazier et al., 2021). [aafp.org]
3. Supports Targeted Treatment
Laboratory testing can identify the specific organism responsible, helping clinicians choose the most appropriate and effective treatment (Tosti, 2026). [emedicine….dscape.com]
4. Reduces Misdiagnosis
UK guidance highlights that many nail conditions, including psoriasis and trauma, can mimic fungal infection—reinforcing the importance of testing when the diagnosis is uncertain (UK Government, 2019). [assets.pub…ice.gov.uk]
Conditions Commonly Mistaken for Fungal Nails
Several conditions can appear very similar to fungal nail infections:
Nail Trauma
Repeated pressure (such as tight footwear) or previous injury can cause thickening, discolouration, and nail lifting (Foot & Ankle Associates, 2024). [footandanklesnh.com]
Nail Psoriasis
A common inflammatory condition that can cause pitting, thickening, and separation of the nail. It can closely resemble fungal infection and may coexist with it (Haneke, 2020; WebMD, 2024). [emjreviews.com], [webmd.com]
Bacterial Infection
Some bacterial infections can cause discolouration (such as green or dark nails) and nail separation (Prime Foot Clinic, 2025). [primefootclinic.com]
Inflammatory Skin Conditions
Conditions such as eczema or dermatitis can affect nail health and growth.
Age-Related Nail Changes
Natural ageing can lead to thickened, more brittle or discoloured nails, which are often mistaken for fungal infections.
Why “Treat First, Test Later” Isn’t Best Practice
Starting treatment without confirmation may:
- Delay the correct diagnosis
- Lead to ineffective treatment
- Increase unnecessary costs
Current best practice recommends confirming fungal infection before treatment is started, particularly if oral medication is being considered (Frazier et al., 2021). [aafp.org]
Our Approach at Kin Body and Sole
We pride ourselves on delivering safe, evidence based podiatry care. Our approach includes:
- Thorough clinical assessment
- Dermatophyte testing when appropriate
- Clear explanation of findings
- Tailored treatment plans
Our goal is to provide accurate diagnosis and effective long-term management, not just temporary improvement. Once a fungal infection is confirmed, simple steps can help prevent nail fungus returning or spreading to other nails
When Should You Seek Advice?
If you notice changes such as nail thickening, discolouration, or lifting, it is always best to seek professional advice early. Early diagnosis improves treatment outcomes and helps prevent ongoing nail damage.
Final Thoughts
Not every nail that looks fungal is fungal. Dermatophyte testing ensures accurate diagnosis, appropriate treatment, and better outcomes for patients.
At Kin Body and Sole, we are committed to delivering trusted, professional care based on clinical evidence and best practice.
References
- Frazier, W.T., Santiago-Delgado, Z.M. and Stupka, K.C. (2021) Onychomycosis: Rapid Evidence Review. American Family Physician. [aafp.org]
- Gupta, A.K., Hall, D.C. and Cooper, E.A. (2022) Diagnosing Onychomycosis: What’s New? Journal of Fungi. [ncbi.nlm.nih.gov]
- Gupta, A.K. et al. (2024) Clinical diagnosis and laboratory testing of abnormal appearing toenails. Journal of Fungi. [mdpi.com]
- Haneke, E. (2020) Differential diagnosis of nail psoriasis and onychomycosis. EMJ Dermatology. [emjreviews.com]
- Tosti, A. (2026) Onychomycosis Workup. Medscape. [emedicine….dscape.com]
- UK Government (2019) Fungal skin and nail infections: diagnosis and laboratory investigation. [assets.pub…ice.gov.uk]
- WebMD (2024) Nail fungus vs nail psoriasis. [webmd.com]
- Wongyikul, P. et al. (2026) Global prevalence of onychomycosis. Journal of Epidemiology & Community Health. [jech.bmj.com]
- Foot & Ankle Associates (2024) Differentiating nail trauma and fungal nails. [footandanklesnh.com]
- Prime Foot Clinic (2025) Nail conditions mimicking fungal infections. [primefootclinic.com]