Immersion Foot: What it is and How to Treat it

September 13, 2023

4 mins

As humans, we rely on our immune system to protect us from potential hazards in the world. Maintaining a strong immune system is essential to surviving, but it can’t always protect us from dangerous conditions like immersion foot.

Keep reading to learn more about Immersion foot and how to treat it.

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What is Immersion Foot?

Immersion foot syndrome is a form of tissue damage that comes from prolonged exposure to wet conditions. It’s most commonly known by the nickname “trench foot.” History buffs should immediately recognize this name, as it played a crucial part in World War I. 

Trench warfare was extremely common during the Great War. Soldiers would spend months at a time stuck in waterlogged trenches that were full of rain water and freezing cold mud. These conditions resulted in thousands of cases of trench foot. More than 75,000 British and 2,000 American soldiers died as a result of this disease. 

This condition also impacted sailors during the Second World War and infantry during the Vietnam War.

In modern times, immersion foot primarily affects people who are homeless – though it occasionally springs up in hikers, hunters, and alcoholics. 

What Causes Immersion Foot? 

Immersion foot is the result of having wet feet for long periods of time. Your feet will start to lose blood circulation and nerve function whenever they remain wet for a prolonged period of time. The loss of nerve function can impair your ability to feel pain. It is entirely possible that you can contract immersion foot unknowingly.

Frostbite is a condition resulting from overexposure to extremely low temperatures. Frostbite and immersion foot have similarities in symptoms, so the two conditions are commonly confused for one another. 

It’s a common misconception that the water must be cold or freezing to get immersion foot. Although immersion foot occurs more often in cold weather, you can still contract it in warm weather. 

What are the Symptoms of Immersion Foot?

The symptoms of trench foot can vary depending on how long your foot has remained wet. Immersion foot primarily affects the toes and heels, but in severe cases, it can affect the entire foot.

Losing circulation in your feet will deprive them of oxygen and essential nutrients – which are transported through your blood. The longer that your feet go without these necessities, the more severe the symptoms will be. 

These are some potential symptoms you may experience when suffering from immersion foot:

• Tingling or itching sensation

• Aches and pains

• Swelling

• Cold and blotchy skin

• Red or blue discoloration of skin

• Numbness

• Heavy feeling in the affected foot

• Distinct smell of decay

• Severe blisters, ulcers, and open sores

• Permanent nerve damage

• Loss of function in the affected foot

• Gangrene

• Amputation

How is Immersion Foot Diagnosed?

The symptoms of immersion foot are fairly unique and it won’t be particularly difficult for your doctor to diagnose. The challenging part will be determining the severity of your condition. 

Your doctor will need to perform a thorough physical examination of your affected foot. Patients may undergo several different tests to determine the extent of tissue and nerve damage.

Each care of immersion foot falls into one of the following stages:

Stage one: exposure

The loss of sensation is typically the primary symptom in this stage and can feel similar to the effects of local anesthesia.The foot will become very heavy and it can have an impact on your ability to stand and walk. The skin on your foot might turn bright red for a little while, but often becomes completely pale as a result of blood loss.

Stage two: pre hyperemia 

This stage will begin as soon as your feet are removed from the wet conditions. It will normally only take a few hours to pass through this stage, but it could take as long as several days.The skin on your foot will turn a shade of blue, indicating that the blood in your foot is lacking oxygen. Additionally, your foot may feel numb and cold to touch. It’s common to experience some swelling during this stage.

Stage three: hyperemia

The third stage will begin fairly abruptly and can last for a few days or several weeks. During this stage, your foot usually becomes bright red and hot to touch. The feeling of numbness is often replaced with intense pain. Bruising or blisters may appear during this stage. Most cases of immersion foot will be resolved with treatments during this stage. For severe cases, the symptoms will continue to the next stage.

Stage four: post-hyperemia

The final stage can last for a few months, linger for a few years, or be permanent. Unless you have tissue necrosis, your foot will appear as normal as it did in the past. It's common for your foot to stay cool and become very sensitive to cold temperatures. You will most likely experience chronic pain-- especially in response to being cold. Excessive sweating is also a common symptom. Amputation can be the only course of action if tissue necrosis continues. 

How is Immersion Foot Treated?

The treatments for immersion foot have vastly improved since the days of World War I. In those days, a bath made from a combination of lead and opium was one of the first treatments. Sometimes the feet would be submerged in mercuric chloride, iodine, or various types of alcohol. Medics would also massage plant-based oils into the affected areas.

In modern times, treating immersion foot is fairly simple. Patients are instructed to keep feet dry and clean. They are also told to rest and elevate their feet to encourage blood circulation. Taking ibuprofen, aspirin, or naproxen may be used to help reduce the pain and swelling.

How Do You Prevent Immersion Foot?

Contracting immersion foot will usually take about 12 hours of exposure to wet conditions. As long as you have access to proper protective clothing, dry shelter, proper nutrition, and the ability to stay properly hydrated, you should be fairly safe. 

These are some additional tips to avoid contracting immersion foot:

• Wear waterproof boots that fit properly and allow for circulation

• Wear socks that are thick and made of wool

• Remove your boots and socks at least twice a day to dry them if you’re in humid or wet conditions

• Change out of wet socks as soon as it is feasible

• Never sleep in wet socks and shoes 

• Dry your feet before putting on your socks

• Dry your socks completely before putting them on your feet

• Keep your feet as clean and dry as you possibly can

• Elevate your feet when possible to promote blood circulation

How Rex MD Can Help

Immersion foot is not nearly as common as it was long ago. Still, it’s a serious condition if left untreated and it could result in dangerous symptoms. Fortunately, preventing and treating this issue is very simple. If you suspect you have contracted immersion foot -- no matter what stage you may have -- seek medical attention immediately.

Rex MD's parent company LifeMD can connect you with a licensed healthcare provider who can offer guidance on treating this condition and prescribe medication, if appropriate.

Just make an appointment, and you'll be able to virtually meet with a doctor or nurse practitioner today, without even having to leave your home!