Pain in the big toe is a common complaint. It's often put down to a "bunion", and patients are referred with a request for removal of the bunion. Although hallux valgus is, indeed, one of the commonest problems in the foot, not all hallux pain comes from a bunion.

What sort of problem is it?

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True bunion pain - medial abrasion from hallux valgus

Usually the most useful starting point is to ask which part of the toe hurts:
  • pain on the medial side is usually due to abrasion on the shoe in hallux valgus
  • pain over the dorsum of the MTP joint is often due to arthritis in the joint (hallux rigidus) - sometimes it’s mainly coming from the joint itself, sometimes it’s caused by abrasion of the tissues between a dorsal osteophyte and the shoe
  • pain along the side of the nail is usually caused by an ingrowing toenail, or less often by a subungual exostosis growing under the nail
  • pain under the toe may be due to excess pressure when walking, or to a sesamoid problem, MTP or IP joint arthritis or synovitis of FHL.
  • pain all over the toe can be referred from an arthritic joint, or infection, but is often neuritic pain from a local nerve irritation, regional pain syndrome or L5 radiculopathy

Making it clearer

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This foot cannot fit comfortably into this shoe. Make the shoe fit the foot, not the foot fit the shoe!

Medial abrasion pain is usually worse with shoes on. The seam between the main part of the shoe and the toe box sometimes digs into the painful area. Frey (1993) showed that American women wore shoes that were, on average, 1cm narrower than their feet. Informal study in our clinic shows much the same. Some patients will already have tried lots of different shoes to find something reasonably comfortable. Others have not tried alternative shoes, and may come to clinic in shoes that are obviously much narrower than their feet, and have heels that are forcing the toes deep into a narrow toe box. A few people have already had skin blistering, ulceration or infection over the bony prominence and this would be a definite indication to offer surgery. Where abrasion or ulceration is combined with neuropathy or poor circulation the risks of both surgery and non-surgical treatment increase but surgery should definitely be discussed.
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Dorsal pain and osteophyte in hallux rigidus

Dorsal pain may also be worse with shoes, especially if the main cause of the pain is skin abrasion over a dorsal osteophyte. Again, a history of blistering, ulceration or infection over the osteophyte, especially if there is underlying neuropathy or poor circulation, should prompt discussion of surgery. If the pain is mainly caused by arthritis with dorsal impingement in the joint, higher heels tend to make it worse and it often gets worse with time spent walking. Arthritic pain is usually helped by analgesics, at least at first. Sometimes what makes the patient consult is that they can't get pain relief with simple analgesics any more. Arthritic pain sometimes radiates up or down the toe, but on questioning it's usually worse at joint level. Some people with pain in the joint have a clear history of impaction or forced dorsiflexion injury. If the problem clearly dates from such an injury they may have an osteochondral joint surface injury or damage to the plantar plate, when MRI and/or arthroscopy may be helpful.
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Lateral nail fold pain caused by an ingrowing toenail

Nail pain can be along the side of the nail or in the nail bed. Pain along the nail edge is usually due to an ingrowing toenail, and the patient will usually describe episodes of inflammation and possibly purulent discharge from the nail fold. It's important to ask about reasons for immunosuppression, especially diabetes and medications. Ask about how the patient trims their nails and whether they have tried any method to prevent the nail impinging on the nail fold skin - podiatrists have a variety of techniques that are worth trying.

Pain under the nail itself can be due to fungal infection - ask about fungal infection elsewhere in the foot. Subungual exostoses can press under the nail but often present in the nail fold and can be mistaken for ingrowing toenails. There is sometimes a history of trauma with an exostosis. Pain under the nail can also be caused by infection in the phalanx itself and rarely by nail bed tumours, especially melanomas. Infection and tumours tend to cause increasing pain that is unaffected by position and may be present at night and insensitive to simple analgesia. With infection there may be a history of injury or (in neuropathic patients) ulceration and the person may describe fever, sweating or shaking.

Pain under the toe may come from pressure, an arthritic MTP joint or from one of the sesamoids. Increased pressure under the 1st metatarsal head often causes calluses which the patient may indicate as the site of pain. Ask about other sites of pressure, whether the patient has noticed anything odd about the shape of their foot or the way they walk. People with cavus feet often have pressure under a plantarflexed first ray, and cavus tends to run in families even if there is no definite neurological cause, so make a point of asking whether anyone else in the family has foot problems.

Sesamoid pain is usually reasonably localised to the sesamoid bone but it often takes some questioning to clarify this. Pain further down the plantar surface of the toe may be due to FHL synovitis, IPJ arthritis or skin or deep infection - again, questioning is mainly directed at localising the maximum pain to guide examination.

Pain all over the toe can be difficult to diagnose. Commonly it is referred from an arthritic MTP joint and direct questioning identifies the joint line as the site of maximum pain. If the patient has had surgery or an injury, neuritic pain or complex regional pain syndrome can cause pain all over the toe and sometimes involving the foot too. An L5 radiculopathy, often due to a L4/5 disc prolapse or root canal stenosis, can cause pain in the big toe and the medial foot, often with tingling or numbness. Nerve pain has a severe, burning, throbbing character and may have other neurological symptoms. Regional pain syndrome often has swelling, colour changes and sweating in the early stages. Generalised throbbing, swelling and redness can also be due to skin or deep infection and the person should be asked about injury, immune competence, circulation and neuropathy.

Remember to ask general questions about health and systemic conditions that can affect the foot.

"Before it gets any worse…"

Some patients are brought to the clinic not because of what their feet are like now, but because of concern about what they may become like, based on the experience of mother or grandmother. Ask about any background that may have exacerbated mother's feet (especially inflammatory arthritis). Unless the index patient has very severe hallux valgus with incongruity at a young age, when it may be best to offer at least a holding procedure, it is best to treat the feet on their own merits and take the opportunity for some education about shoes.

Reviewing the history

By asking relevant questions you will usually have a good idea of the most likely cause of pain, which you can sort out further by examination. Sometimes there will be one or two possibilities, or you may be considering a combined diagnosis such as hallux valgus with arthritis of the MTP joint. Again, examination should be focused on clarifying such diagnoses.