Overview

The human foot is an advanced, biomechanically complex structure, designed to support the body's weight and force multiple times its weight during propulsion. Approximately 26 bones can be found within the human foot. They may be grouped into three sections, which are composed of the following:

• Tarsal bones: Seven tarsal bones are present
• Metatarsal bones: There are five metatarsal bones present
• Phalanges: There are a total of fourteen phalanges

There are five metatarsal bones. The second metatarsal bone, also known as the second toe, contains metatarsal and the joints in between them. A second toe is also the longest of all metatarsal bones as it is the most proximal in extent. The second toe has three phalanges connected. The second toe and even the whole of your forefoot as well as the ball of the foot, is sustained upright when you stand by biomechanics.

The metatarsophalangeal (MTP) joint is the joint between your metatarsal bone and the proximal phalanx. There is a thin joint capsule within these joints as well as numerous ligaments holding this structure in place.¹

Pain and swelling of the second toe

The commonest source of pain in the second toe is due to capsulitis. Capsulitis is an inflammatory process of the ligaments surrounding the second toe. These ligaments surround the toe joint at the bottom in the form of a capsule, which helps to make it move freely. It primarily causes a significant amount of pain. Capsulitis may affect any of the toes on the foot, but secondly, it more frequently occurs on the second toe.³

Capsulitis of the second toe occurs depending on many different factors. It may be a result of overuse, genetic factors, and certain disease conditions like arthritis. Athletes and active sportspeople more often experience pain in the second toe. Therefore, early diagnosis of the condition is necessary if you are experiencing any second toe capsulitis pain.

Capsulitis of toe joints is seen as a common condition of the forefoot and can occur at any age.² Goes untreated, it can eventually lead to weakening of the surrounding ligaments and an increased potential for toe dislocation. Because of this, capsulitis is often also known as “predislocation syndrome.”^4,3

Symptoms

The symptoms can worsen without treatment. It's critical to identify symptoms in the earliest stages. Initial symptoms include:

• Pain occurs especially on the ball of the foot, and can feels like there's a marble present in the shoe. 
• Swelling with pain at the base of the toe
• Difficulty wearing a shoe
• Pain worsens when you stand, flex, walk, or run your feet, especially barefoot on a hard surface, and relief when you are at rest
• Sharp or shooting pain, numbness³ 

In more advanced stages, the supportive ligaments weaken, and the joint fails to stabilise the toe. The unstable toe moves toward the big toe and eventually crosses over and then lies on top of the big toe, resulting in crossover toe, the end stage of capsulitis. The symptoms of crossover toe are the same as those developed during the earlier stages. Whereas crossover of the toe may cross over time, it may quickly and pose as a result of injury or overuse.³

Causes

Capsulitis of the second toe is commonly assumed to arise from abnormal mechanics of the foot, wherein the ball of the foot under the toe joint sustains too much weight-bearing pressure.³

In some cases, it occurs by a single factor. However, in most cases, metatarsalgia (pain and inflammation in ball of foot) is caused by several factors, include:

Intense training or activity

In particular, distance runners are more likely to suffer from metatarsalgia because the impact produced upon the landing has to be borne at a considerable weight by the front part of the foot. Generally, anyone who exercises in a high-impact sport is prone, and more specifically so if your running shoes fit poorly or are old.

 Certain foot shapes

A high arch puts additional pressure on the metatarsals. A second toe, which is larger than the big toe also produces more weight than usual on the head of the second metatarsal.

Foot deformities

Putting your foot in unnatural positions because of wearing shoes that are too tight or because of high heels can cause a hammertoe (the downward curl of the toe) and (swollen, painful bumps at the base of your big toes) bunions. These conditions can cause metatarsalgia.

Excess weight

As most of your bodyweight puts pressure on your forefoot when you move or stand, extra weight mean more pressure is put on your metatarsals. Maintaining a healthy weight might reduce or eliminate such symptoms.

Poorly fitting shoes

People that regularly wear high-heeled shoes commonly develop metatarsalgia because high heels transfer extra weight to the front of the foot. Shoes with a narrow toe box, or athletic shoes that lack support and cushioning also can contribute to the problem.

Stress fractures

Metatarsals or toe bones can break be painful, and change the way you put weight on your foot.

Morton's neuroma

Fibrous tissue around a nerve may contain benign tumour growth that usually occurs between the third and fourth metatarsal heads. It produces similar symptoms to metatarsalgia and can also be a cause for metatarsal stress.⁵

Freiberg's disease

This is a relatively rare disease where the death of some bone (osteonecrosis) happens in the second metatarsal. This condition is more frequently encountered in teenage people assigned female at birth.

Arthritis or gout

Because arthritis may cause inflammation of the joints of the ball of the foot or the big toe, it can be a possible cause of metatarsalgia.

Diabetes

Diabetes can affect the nerves in the feet, which can cause metatarsalgia. This usually occurs when diabetes has been prevalent for a long time, and blood sugar levels are not well controlled.⁷

Diagnosis

The reason an accurate diagnosis is crucial is because the symptoms can so closely resemble those of another condition, Morton's neuroma, for which completely different treatments will be prescribed. In diagnosing, the foot and ankle surgeon examines the foot, palpates it,, and manoeuvres it to identify the symptoms. The surgeon will also look for possible causes and test the joint's stability. Commonly, x-rays and other imaging studies are needed for enhanced resolution.³ 

Treatment

Treatment is referred to a bone specialist (orthopaedist) or a foot specialist (podiatrist).⁶ It basically depends upon the underlying cause.⁷

Nonsurgical treatment

The early stage of a condition is the best time to treat a swollen second toe, before the toe begins to drift toward the big toe. In this case, there is a good opportunity to stabilise the joint, reduce symptoms, and address the cause directly through nonsurgical means.³

The surgeon can treat the initial capsulitis with any one or a combination of the following early treatments.

Rest and ice

Keeping off the foot and applying ice packs may reduce swelling and pain. Cover an ice pack with a thin towel then apply to your skin. Rub for 20 minutes, then wait at least 40 minutes before icing again.

 Oral medications

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, may reduce the pain and inflammation.

Taping/splinting

At some point, the toe may be taped so that it stays in its proper position. It also helps to prevent the toe from drifting and to relieve pain.

Shoe modifications. 

Shoes having rigid soles are best to use as these are supportive and restrict movement to minimise pressure on the ball of the foot.

Orthotic devices

Sometimes custom shoe inserts are very helpful; these can include orthotics such as an arch support or a metatarsal pad that shifts the weight away from the joint.

Stretching

Stretching exercises may be recommended for patients with tight calf muscles.³

Maintain a healthy body weight⁷

Immediate relief for metatarsalgia

Over the counter painkillers such as paracetamol or ibuprofen may help to reduce pain and swelling. Ice packs can also provide relief in some cases. Resting your foot and elevating it can help. Pads or arch supports in the shoes may help reduce pain quickly.⁷

When is surgery needed?

Once there is movement towards the big toe, the second toe is unlikely to return to its normal position unless surgically corrected. The procedure best for the individual patient will be determined by the foot and ankle surgeon.³

Prevention

• Wear well-fitting, low-heeled, and wide-toe area shoes. This will help prevent some causes of metatarsalgia, such as Morton's neuroma
• Wear good, well-fitting athletic shoes during running and sports that involve high impact to the feet
•  Maintaining a healthy body weight. For people with diabetes, better control will minimise the likelihood of foot problems⁷

Summary

A swollen second toe could be due to injury, overuse, genetics or underlying medical issues. The common causes are sprains, fractures, bursitis, and conditions such as arthritis. However, sometimes irritation or inflammation can also occur from poor footwear that puts too much pressure on the toe. Sometimes, it is caused by a condition known as "Morton's toe," which is defined as a second toe that is a bit longer than the great toe, and puts a little more stress. It may be treated by rest, ice, compression, elevation, (RICE) and proper footwear, but if swelling continues, the patient is advised to see a doctor for a medical checkup.