Nail fungus after gel polish is a common worry, but a change in nail colour does not necessarily mean fungus. A bacterial infection (the so-called "mould"), the nail separating from its bed (onycholysis) or mechanical damage can look similar. The exact cause is determined by a doctor, often after examining a nail sample in a laboratory. The nail technician's job is to notice changes, not to carry out a service on a damaged nail and to advise the client to see a doctor. This article is for information only and does not replace a medical consultation.
Fungus, mould or onycholysis: how to tell the difference
| Condition | What it usually looks like | What it is |
|---|---|---|
| Nail fungus (onychomycosis) | The nail is yellowish, white or brownish, thickens, crumbles and may lift away; toenails are affected more often | A fungal infection which, if left untreated, can spread to other nails |
| "Mould" – a green spot | A greenish spot, later dark green or blackish, under the coating | Most often an infection caused by the bacterium Pseudomonas aeruginosa, not mould |
| Onycholysis | Part of the nail has separated from the nail bed, looking white and opaque | Separation caused by trauma, chemicals, skin conditions or infection; bacteria and yeasts settle more easily under a lifted nail |
These conditions cannot be reliably told apart by appearance, and they can also occur together. That is why a nail technician should not tell a client "this is fungus" or "this is just mould" – it is enough to say that a doctor needs to assess the change.
Not every spot is an infection. Whitish, rough areas on the nail surface, noticed right after the coating is removed, are often damage to the surface layers of the nail caused by long wear or overly aggressive removal. They grow out together with the nail. If the spots do not disappear, spread or change colour, it is worth consulting a doctor.
Why spots appear after gel polish
- Lifted coating. A gap forms underneath where moisture collects and micro-organisms multiply. It is especially risky to glue down or paint over lifted coating instead of removing it. We explain why coating lifts in the article why gel polish cracks.
- Coating worn for too long. Grown-out coating lifts more easily from the edge of the nail.
- Constant moisture. Long periods of work with water without gloves make it easier for bacteria and yeasts to settle under a lifted nail or coating.
- Nail trauma. Filing too deeply, aggressive cuticle work or peeling off the coating can cause onycholysis.
- Improperly processed tools. Reusing disposable files or using unsterilised tools can transmit infection.
- Allergy. A reaction to acrylates can show up as skin redness and nail separation. Read more in the article allergy to gel polish.
Can nails affected by fungus be polished
No. The coating hides changes, seals the nail and makes it impossible to see whether the condition is improving. Moreover, working with tools on an affected nail can transmit the infection to other nails or to other clients. Lithuania's National Public Health Centre (NVSC) also states that caring for fungus-affected nails and taking nail samples for laboratory tests count as personal healthcare services, so they may not be provided in a beauty salon.
Whether the other, healthy nails may be coated while one is being treated should be decided by a doctor.
What the nail technician must do on noticing changes
- Stop the service on the affected nail: do not file, trim or coat it.
- Calmly explain what you see without diagnosing: "I can see a change that a doctor should assess."
- Advise the client to see a family doctor or a dermatologist and, for toenails, also a podiatrist working in a licensed healthcare facility.
- Note the date and which nail is affected on the client's record card.
- Dispose of used disposable items, clean, disinfect and sterilise reusable tools, and disinfect work surfaces.
- Return to services only once the doctor has given permission.
How to reduce the risk for the client
The client can reduce part of the risk herself, and the nail technician should remind her of this after every appointment:
- if you notice lifted coating, do not wait for your next appointment – it needs to be removed, not glued down or picked off;
- do not wear the coating for longer than your nail technician recommends;
- wear gloves when washing up or cleaning, and dry your hands well after washing, especially around the nails;
- do not pick at your cuticles or bite your nails – damaged skin around the nail is more easily infected;
- if you notice any change, tell your nail technician before the appointment, not after it.
Hygiene that protects against transmission of infection
Lithuanian hygiene standard HN 117 "Health safety requirements for beauty services" sets clear rules that also protect against fungal infections:
- when a service breaks the skin (for example, cutting cuticles), only sterile instruments are used, and they are unpacked in front of the client;
- reusing disposable instruments is prohibited, and instruments that cannot be properly disinfected or sterilised must be disposable, for example disposable adhesive files;
- the instrument disinfectant must be effective against bacteria, viruses, tuberculosis bacteria and fungi;
- an ultraviolet device may only be used to disinfect cleaned instruments that cannot tolerate chemical solutions and heat and are used without breaking the skin – this is not sterilisation;
- clean or disposable covers and wipes are used for every client.
We described how to put this into practice, step by step, in the guide how to sterilise manicure tools. You will find disinfectants, sterilisers and sterilisation pouches in the disinfection and sterilisation section.
Nail fungus after gel polish: when you must see a doctor
It is worth seeing a doctor whenever the cause of a nail change is unclear. Do not delay if:
- the changes are spreading to other nails, or the nail is thickening, crumbling or lifting;
- there is pain, redness, swelling or pus around the nail;
- you have diabetes or a weakened immune system;
- the spot does not disappear as the nail grows out;
- a dark lengthwise stripe or spot has appeared under the nail and you do not know the cause.
Treatment is prescribed only by a doctor. Treating nail fungus usually takes months, because a healthy nail has to grow out completely.
How to care for your nails after treatment
- Follow your doctor's instructions and return to gel polish only with their permission.
- Keep your nails short, clean and dry. Do not share towels, clippers or other personal tools.
- Wear flip-flops in swimming pools and communal showers, and change your socks every day.
- When you go back to coatings, do not let them lift and do not wear them for too long. Remove lifted coating rather than gluing it down.
- Do not peel off the coating – we explain how to remove it in the article how to remove gel polish safely. Tips for weakened nails can be found in the article nail recovery after gel polish.
Frequently asked questions
Can I have gel polish if I have nail fungus?
No. An affected nail must not be coated: the coating hides changes and gets in the way of treatment, and tools can transmit the infection. See a doctor first.
What does the start of nail fungus look like after gel polish?
Most often a yellowish, white or brownish spot starting at the edge of the nail; later the nail may thicken and crumble. However, other conditions look similar, so only a doctor can determine the cause.
What is the difference between nail mould and fungus?
So-called mould – a greenish spot under the coating – is most often a bacterial infection that appears when moisture collects under lifted coating. Fungus is a fungal infection that more often changes the thickness and structure of the nail. In both cases you need to consult a doctor.
Can nail fungus be spread through manicure tools?
Yes, infection can be transmitted by improperly processed tools. That is why reusable tools must be cleaned, disinfected and sterilised, and disposable ones used only once.