Nail Fungus: What Actually Works

Sep 17

8 min read

Updated: Sep 29

中文摘要在文末

Nail fungus is one of the most misunderstood things I treat, and the misunderstandings are what keep people from getting it sorted.

Let me clear up the two biggest ones first.

It's not a hygiene problem. People are often quietly ashamed of it, and assume it reflects on how clean they are. It doesn't. Scrupulously clean people get nail fungus.

It's not just something that happens with age. Older nails are more susceptible, but this is an infection, not a natural consequence of getting older. It's treatable at any age.

Both of those beliefs stop people seeking treatment, which is a shame — because it's common here, and it's fixable.

Who actually comes in early

Here's something I find genuinely interesting.

The people who seek treatment earliest are usually young women who want their nails to look nice. Not the people with the most severe involvement — the people who care most about appearance.

Worth knowing if you get your nails done: instruments that contact the nail can transmit infection between clients, so proper sterilisation between customers matters. Most places take this seriously. It's a reasonable thing to ask about, in the same way you'd ask anywhere that uses instruments on you.

Meanwhile people with thick, discoloured, crumbling toenails often wait years, because they've concluded it's just how their feet are.

The two routes: tablets or topical

There are two ways to treat this, and I want to explain my reasoning honestly rather than just tell you what I'd choose.

What the textbooks say: if it's one or two nails with limited involvement, use a topical antifungal. If more nails are involved or the involvement is extensive, use oral treatment.

What I generally do: I lean towards oral. And the reason is practicality rather than any disagreement with the principle.

Why topical nail treatment usually fails

This is the part nobody explains properly, so here it is.

Applying antifungal treatment to a nail isn't like applying cream to skin. The infection is underneath and within the nail plate, and the nail is a barrier specifically designed to keep things out. You can't just paint over the top and expect it to reach.

So the actual procedure, done properly, is:

Soak the affected fingers or toes in warm water for five to ten minutes
Dry thoroughly
File the nail down — thinning it as far as you can go before it becomes painful, effectively shaving the nail down until you're close to the infection
Then apply the medication

Depending on the product, that's either near-daily or weekly. Indefinitely, for months.

And here's my honest admission: that requires a skill I don't have.

I'm serious. Filing a nail down to precisely the right thinness — far enough to matter, not so far that you damage the nail bed or cause pain — is genuinely a manual skill. Someone who does their own nails regularly might manage it. I couldn't do it reliably on myself, and I'm not going to prescribe a treatment whose success depends on a technique I know most people won't execute well.

So when someone tells me they used a topical nail product for months with no result, my first thought usually isn't that the medication failed. It's that the filing step didn't happen, or didn't happen properly — which means the medication never reached anything.

If you've been filing and applying diligently and getting nowhere, come and let me look. It may simply be that your degree of involvement was never going to respond to topical treatment.

How oral treatment works, and why it takes so long

This is the part patients most need to understand, because misunderstanding it is why people give up.

The tablets do not repair your nail. Nothing does. A damaged nail stays damaged.

What the treatment does is stop the infection spreading further into the nail while the nail grows out naturally, carrying the damaged portion towards the tip, until eventually you can cut it off entirely.

So the timeline isn't set by the medication. It's set by how fast your nails grow.

Which is why fingernails clear faster than toenails — considerably faster. Toenails are slow, and the treatment feels like nothing is happening for a long stretch, because the visible damage stays visible until it has grown out.

The way to judge progress is to look at the base of the nail, near the cuticle. That's where the new, healthy growth appears first. If there's clear nail coming through at the base while the damage sits further up, the treatment is working — even though the nail as a whole still looks bad.

I tell patients this at the start so they know what to watch. Otherwise, three months in, they see a nail that still looks awful and conclude it's all been pointless.

Dosing schedules and monitoring

There are two general approaches with oral treatment: a pulse schedule, where you take the medication for a week and then have several weeks off before repeating, or daily dosing. Which one depends on the medication and on you.

I'm deliberately not publishing doses here. These are prescription medications, they interact with a range of other drugs, and the right choice depends on your medical history — this needs a consultation, not an article.

Monitoring. If oral treatment needs to run beyond about three months, we check liver function, because these medications can affect the liver. The chance isn't high, but it's real, and if the liver enzymes rise significantly, we stop and reassess.

My position on that is simple: your liver is more important than a nail. That's not a close decision and I won't agonise over it.

I don't routinely screen everyone before starting a short course, but I will if there's something in your history that raises a question, if you're elderly, or if you have other medical problems. Which is why I ask about all of that before prescribing anything.

Setting expectations honestly

Fingernails: months. Toenails: longer. Often considerably longer.

The infection stops progressing relatively early. The appearance takes as long as your nail takes to grow.

If someone offers you a treatment that clears a fungal toenail in a few weeks, they are describing something cosmetic rather than something curative.

What I do when I think compliance will fail

An honest note, because you asked the same question in the room.

Sometimes I meet someone where I can see the treatment won't be completed — the schedule doesn't fit their life, or the follow-up won't happen, or they're clearly not invested in a months-long process for a nail that doesn't bother them much.

I don't think the right response is to prescribe anyway and hope. Half-completed antifungal courses achieve very little and aren't risk-free.

So I'd rather have the honest conversation: what would actually make this workable for you? And if the answer is nothing right now, that's a legitimate outcome. Nail fungus is not an emergency. Come back when it matters to you, or when the situation changes. I'd rather you start when you'll finish.

Reducing your chances of a repeat

Shoes are a reservoir. If you've had a foot or nail infection, the shoes are probably carrying it. If they're not expensive or precious, my honest advice is throw them out. If they're worth keeping, treat them — with proper advice from a shoe shop about how, so you don't ruin them.

Sandals in shared showers. Gyms, changing rooms, communal bathrooms. Never barefoot.

Keep feet dry. Dry properly between the toes after showering. Change out of damp socks.

Treat athlete's foot properly, because foot infections spread to nails. Which brings me to the rule I apply across all fungal infections: once it looks clear, keep going for another week or two. Fungal organisms are resilient, and "looks clear" is not the same as "is clear."

If you want it looked at, come in. Klinik Dr Tan (Skin & Acne), Lot 27, Ground Floor, Block D, Lintas Square, Kota Kinabalu. WhatsApp 017-234 7328. Appointments preferred.

I'm a GP with a strong interest in skin, not a dermatologist.

Book a consultation with Dr. Tan — Book Online or WhatsApp 017-234 7328.

Read more about Fungal Infections : Fungal Skin Infections, 5 Fungal Infection Mistakes, Combination Steroid-Antifungal Creams

简要说明

我是陈医生，亚庇 Lintas Square 的 Klinik Dr Tan（皮肤与暗疮）。我是对皮肤有专长的普通科医生，不是皮肤专科医生。

先澄清两个最大的误解：灰指甲不是卫生问题（很爱干净的人一样会得），也不只是年纪的自然结果（这是感染，任何年纪都能治）。这两个想法让很多人不去求医。

最早来求医的通常是想要指甲好看的年轻女性。如果你有做指甲，值得知道的是：接触指甲的器械可能在客人之间传播感染，所以器械消毒很重要。多数店家都很注重这一点，而你也可以合理地询问——就像任何会对你使用器械的地方一样。

两条治疗路线：口服或外用。 教科书说：一两片指甲、范围小 → 外用；范围大 → 口服。我通常倾向口服，理由是实际可行性。

为什么外用治疗多数会失败：感染在指甲底下和里面，而指甲本身就是设计来阻挡东西的屏障。正确的做法是：温水泡5–10分钟 → 擦干 → 把指甲磨薄（磨到快要痛之前的极限，等于削薄指甲直到接近真菌）→ 才上药。视产品而定，几乎每天或每周一次，持续数月。

老实说：这需要我没有的技巧。 我是认真的。把指甲磨到刚好的厚度——够薄才有意义，太薄会伤到甲床和造成疼痛——那是真正的手工技巧。常做指甲的人也许可以，我自己做不好，而我不会开一个成功与否取决于「多数人都做不好的技巧」的疗法。

所以当有人说外用药擦了几个月没效，我第一个念头通常不是药无效，而是磨甲那一步没做，或没做好，药根本没有到达任何东西。如果你已经认真磨甲上药却毫无进展，请来让我看看——也可能是你的严重程度本来就不适合外用治疗。

口服怎么运作，为什么这么久：药物不会修复你的指甲，没有东西可以。受损的指甲就是受损了。药物做的是阻止感染继续往指甲深处扩散，同时指甲自然生长，把受损部分往前推，直到最后可以完全剪掉。

所以时间不是由药物决定，是由你指甲生长的速度决定。 因此手指甲比脚趾甲快得多；脚趾甲很慢，而且很长一段时间感觉毫无进展。

判断进展要看指甲的根部（靠近甲缘那端）——新的健康指甲会先从那里长出来。根部有干净的新甲长出来，就代表治疗有效，即使整片指甲看起来还是很糟。

用药方式与监测：口服有脉冲式（服用一周、停数周、再重复）和每日服用两种，视药物和个人情况而定。我刻意不在文章里写剂量——这些是处方药，会跟多种药物产生交互作用，正确选择取决于你的病史，这需要看诊。

若口服疗程超过约三个月，我们会检查肝功能。 机率不高但真实存在，指数明显上升就停药重新评估。我的立场很简单：肝比一片指甲重要。 这不是难做的决定。

期望管理：手指甲要数月；脚趾甲更久，往往久很多。感染较早就停止进展，但外观的恢复取决于指甲长多快。如果有人说几个星期就能治好灰指甲，那是在描述美容效果，不是治愈。

如果我判断疗程无法完成：我不认为该照开不误然后祈祷。做一半的抗真菌疗程效果很有限，也不是零风险。我宁可诚实地问：怎样才能让这件事对你可行？ 如果现在的答案是「没办法」，那也是合理的结果。灰指甲不是急症——等它对你重要了、或情况改变了再来。我希望你开始的时候就能完成。

减少复发：鞋子是储藏库（不贵重就丢掉，要留请找鞋店专业处理）；共用浴室穿拖鞋；保持脚干燥（趾缝要擦干、换掉潮湿的袜子）；好好治疗香港脚（脚的感染会传到指甲）。以及所有真菌感染共通的原则：看起来好了之后，再继续用一到两个星期。 真菌很顽强，「看起来好了」不等于「真的好了」。