Immersion Foot: How a Dermatologist Tells the 5 Types Apart, Why the Wrong Cream Makes It Spread, and How to Treat It in the Rainy Season
Immersion foot (Interdigital maceration) is a condition in which the skin of the feet and between the toes turns white, soggy, peeling, red, itchy or stinging after the feet have been soaked or kept damp for a long time. In the beginning it is irritant dermatitis from moisture, and within days to weeks it is often worsened by a fungal infection of the feet or athlete's foot (tinea pedis) or by bacteria. This is why immersion foot is not one single disease, and the medicine has to match the type you have.
Many people buy an "immersion foot cream" that does not work, because they put antifungal on skin that is only soggy from water, or put steroid cream on a fungal foot infection until it spreads and gets worse. This article separates immersion foot into 8 types by cause and gives the generic names of the medicines doctors use, their strength, how many times a day, how long to apply them, and the signs that a medicine is working or that you should see a doctor.
What are the symptoms of immersion foot?
Common symptoms, in the order they usually appear
The skin between the toes turns soft, soggy and pale white, especially between the 4th toe and the little toe, which is the narrowest and most humid gap.
The skin peels in thin sheets, cracks into fissures, and stings when it touches water or when you walk.
Itching, which is often worse when you take off your socks or at night.
Foot odor stronger than usual.
If a bacterial infection sets in, there will be discharge, pus, pain and swelling, and the surrounding skin turns red and warm.
How fast the symptoms appear gives a rough clue to the type. Skin soggy from water usually appears within 24-72 hours of wading through water, bacterial infection usually follows on days 3-10, and fungal infection usually becomes obvious after 1-2 weeks and can last for months.
What causes immersion foot? An overview of 3 mechanisms
Every type starts from the same point: the outermost layer of the skin (stratum corneum) swells and turns soggy after long soaking, so the skin's protective barrier is lost. From there it goes one of 3 ways.
Moisture alone: irritant skin inflammation with no infection, which clears once the feet are dry.
Fungi: dermatophyte fungi such as Trichophyton rubrum and T. interdigitale, or Candida yeast, invade the soggy skin and cause athlete's foot.
Bacteria: Gram-negative bacteria such as Pseudomonas, or corynebacteria (Corynebacterium, Kytococcus), cause foul-smelling soggy toe webs, pitted feet, or brown patches.
Risk factors that make it easy to get or to come back include wading through floodwater or standing in wet places for long periods, wearing closed shoes or boots all day, heavy foot sweating, toes pressed together, diabetes, weakened immunity, and fungal toenails, which are a source of fungus that keeps reinfecting the skin of the feet.
Is athlete's foot the same as immersion foot?
Not entirely. Athlete's foot is the name for fungal infection of the feet (tinea pedis) specifically. It can occur all year round in people whose feet stay damp and does not require wading through water. Immersion foot is a broader term for feet that have become soggy from soaking in water, which may be only skin irritation, a fungal infection, or a bacterial infection.
In short, athlete's foot is one cause of immersion foot, but immersion foot is not always athlete's foot. Telling them apart determines whether you need an antifungal, an antibiotic, or simply to keep the feet dry.
Early immersion foot: skin soggy from water (not yet infected)
Appearance: The skin between the toes and on the soles is white, wrinkled and peeling in sheets, with more stinging than itching. It appears 1-3 days after wading through water or wearing wet shoes all day, and usually affects several toe webs on both feet at once.
Cause: Moisture and dirt in the water irritate the skin (irritant contact dermatitis). No germ is the main cause yet.
Severity/urgency: Not severe. It usually improves by itself in 3-7 days if the feet are kept dry, but the soggy skin is a doorway for fungi and bacteria, and if the feet keep being soaked it will move on to the infected stage.
When to see a doctor: You have kept the feet dry for 1 week and it is no better, itching becomes strong and the toe webs peel in flakes, there is discharge or pus, or you have diabetes.
Athlete's foot between the toes (Interdigital tinea pedis)
Appearance: The toe webs peel in white flakes, are soggy and wet, and crack into fissures with strong itching. It often starts on one side between the 4th and 5th toes and then spreads to other webs. It comes and goes and returns every rainy season.
Cause: Dermatophyte fungi, spread from the floors of shared bathrooms, swimming pools, shared shoes or foot towels, and from fungus in your own toenails.
Severity/urgency: Not urgent, but it does not clear by itself. If the wrong type of steroid is applied it spreads over a wide area, and the cracks between the toes are an entry point for bacteria that can cause infection of the leg.
When to see a doctor: You have used an antifungal correctly for 2-4 weeks with no improvement, it has come back more than 2-3 times a year, your toenails are thick and yellow, or you have diabetes.
Dry, scaly fungal infection of the sole (Moccasin type)
Appearance: The soles and sides of the feet are dry, thick and covered with fine powdery white scales, over a wide area as if wearing a slipper. Itching is mild, and many people think it is just dry skin.
Cause: The fungus Trichophyton rubrum, embedded in the thick skin of the sole, so medicines penetrate less easily than in the toe-web type.
Severity/urgency: Not dangerous, but it is chronic and lasts for years, and often comes together with fungal toenails.
When to see a doctor: The skin is still peeling after 4 weeks of treatment, or you are not sure whether it is a fungus or peeling feet from other causes such as dry skin or allergic eczema. The doctor will scrape the skin to test for fungus before giving medicine.
Fungal blisters on the sole (Vesicular type)
Appearance: Clear blisters 1-3 mm across appear in clusters on the arch or sides of the foot with strong itching. They burst and peel in rings. Some people then get itchy blisters on the hands even though there is no fungus on the hands, which is an allergic reaction to the fungus (id reaction).
Cause: The fungus T. interdigitale triggers strong inflammation. It is common in the hot and rainy seasons.
Severity/urgency: Moderate. It looks like vesicular hand and foot eczema (pompholyx), which is not a fungus and needs a different class of medicine. Guessing wrong makes it worse in both directions.
When to see a doctor: Blisters appear in large clusters, walking is difficult, there are blisters on the hands too, or you are not sure whether it is a fungus or blistering eczema.
Bacterial infection of the toe webs (Gram-negative toe web infection)
Appearance: The toe webs are soggy and wet, whitish-green, with the skin coming off as raw patches, discharge and a strong foul smell. It hurts more than it itches, often affects several webs, and spreads under the toes.
Cause: Gram-negative bacteria such as Pseudomonas aeruginosa add to skin that is already soggy from water or to existing athlete's foot. It is common after wading through floodwater and in people who have used antifungal for a long time while the feet are still wet.
Severity/urgency: Moderate to high. Antifungal alone does not help, and in people with diabetes it can spread into a deep infection.
When to see a doctor: See a doctor if you notice a wet green sore, a very foul smell, or pain so severe you cannot walk. The doctor will usually culture the germ before choosing an antibiotic.
Candida infection of the toe webs
Appearance: The toe webs are bright red with white soggy skin, and small red dots or pustules scattered around the edge (satellite lesions), with stinging and itching.
Cause: Candida yeast. It is common in people with diabetes, people whose feet are wet all day because of their work such as dishwashing or farming, and people who have recently taken antibiotics.
Severity/urgency: Not urgent. It responds to azole medicines, but topical terbinafine works less well on Candida than on dermatophyte fungi.
When to see a doctor: It comes back often, in which case blood sugar should be checked, or you also have a Candida rash in the groin, under the breasts or in the mouth.
Pitted and smelly feet (Pitted keratolysis)
Appearance: On the weight-bearing parts of the sole, such as the heel and the base of the toes, there are shallow pits 0.5-7 mm across, like a sole that has been punched with holes, most visible when the feet are wet. The foot odor is very strong and it is mostly not itchy.
Cause: The bacteria Kytococcus sedentarius and Corynebacterium break down the thick skin of the sole in damp, sweaty conditions. It is common in soldiers, athletes, and people who wear boots all day. Read more about smelly feet and heavy foot sweating.
Severity/urgency: Not dangerous, but antifungal does not work because it is caused by bacteria.
When to see a doctor: You are not sure whether the pits are from this condition or from plantar warts, or the odor has not improved after 4 weeks of treatment.
Brown patches between the toes (Erythrasma)
Appearance: The toe webs have reddish-brown patches with finely wrinkled skin and slight peeling, with mild itching. It is usually in the 4th-5th toe webs and may also appear in the groin or armpits.
Cause: The bacterium Corynebacterium minutissimum. It is not a fungus, but it looks so much like athlete's foot that people apply antifungal for months.
Severity/urgency: Not dangerous. It is more common in people with diabetes and people who are overweight.
When to see a doctor: It has not improved after using antifungal. The doctor can check right away with a Wood's lamp, under which the rash glows orange-red.
Feet soaked for several days (Immersion foot / Trench foot)
Appearance: After the feet have been soaked continuously for several days, for example in volunteers or flood victims, the feet are swollen, pale or bluish-dark, numb, with sharp pain. Later they turn red and warm, blister, and the skin peels in large sheets.
Cause: Continuous soaking for more than 12-24 hours injures the blood vessels and nerves of the feet, not just the outermost layer of skin.
Severity/urgency: High. It can lead to chronic sores, tissue death, and numbness that lasts for months.
When to see a doctor: Immediately when the feet are swollen, numb, pale or dark, blistered, or have a black sore. Do not soak in hot water or massage hard. Raise the feet, keep them dry, and go to a hospital.
How to tell the types of immersion foot apart at home (first steps)
White and soggy, stinging, 1-3 days after wading through water, little itching → skin soggy from water
Very itchy, peeling in flakes at the little-toe web, comes back every rainy season → athlete's foot
Whole sole dry and powdery with scale → dry, scaly fungal type
Clusters of clear blisters on the arch → fungal blister type, or blistering eczema, which a doctor must tell apart
Wet, green, strongly foul-smelling, painful → Gram-negative bacteria
Bright red with small red dots around the edge → Candida
Shallow pits on the sole, very smelly, not itchy → pitted feet
Smooth brown patch between the toes, little itching → erythrasma
Swelling, numbness and pallor after several days of soaking → immersion foot, see a doctor
Looking with the eye only gives a tendency. If you are not sure, the rule is not to apply a steroid on your own, and to see a doctor if there is pus or red swelling.
What to apply for immersion foot, by type
The medicine that works depends on the cause. The list below uses generic names, so look at the active ingredient on the label rather than choosing by brand.
For skin soggy from water (not yet infected)
The main thing is to dry the feet. Dry between the toes, expose the feet to air, and change socks as soon as they are wet.
Zinc oxide ointment or cream 10-20%, applied thinly twice a day as a moisture barrier.
If stinging and itching are strong and a doctor has confirmed there is no fungus, hydrocortisone 1% cream may be used twice a day for no more than 5-7 days.
For athlete's foot (dermatophyte fungi)
Terbinafine 1% cream once or twice a day for 1-2 weeks (the toe-web type is usually enough at 1 week).
Clotrimazole 1% cream twice a day for 4 weeks.
Miconazole 2% cream twice a day for 4 weeks.
Ketoconazole 2% cream once a day for 4-6 weeks.
Ciclopirox 0.77% cream twice a day for 4 weeks.
Whitfield's ointment (benzoic acid 6% + salicylic acid 3%) twice a day for 4 weeks. It suits thick, dry, peeling skin and should not be applied on open sores because it stings.
Apply it about 2 cm beyond the edge of the rash, and keep applying for another 1-2 weeks after the skin looks clear, because fungus remains in the skin even when the itching has gone. For a comparison of each class of medicine, read antifungal creams: which active ingredient and how many weeks.
For Candida
Clotrimazole 1% or miconazole 2% cream twice a day for 2-4 weeks.
Nystatin cream or ointment 100,000 units/gram two to three times a day. It works only on Candida and does not work on athlete's foot.
For Gram-negative bacteria between the toes
Soak the feet in an astringent solution to dry the sores, such as dilute potassium permanganate or aluminium acetate solution 1:40, for 10-15 minutes twice a day for 3-5 days.
A topical or oral antibiotic chosen by the doctor from the culture result. For example, in severe cases the doctor may use oral ciprofloxacin.
Any existing athlete's foot usually has to be treated at the same time.
For pitted feet (pitted keratolysis)
Clindamycin 1% gel or erythromycin 2% gel twice a day for 2-4 weeks.
Wash the feet with benzoyl peroxide 4-5%, leave it on for 1-2 minutes, then rinse off.
Reduce sweating with aluminium chloride 15-20%, applied at night 2-3 times a week.
For erythrasma
Fusidic acid 2% cream or erythromycin 2% gel twice a day for 2 weeks.
If it is in several places, the doctor may give an oral antibiotic.
How to tell the medicine is working: Itching and stinging should ease within 3-7 days, and peeling, soggy skin should dry and close over within 2-4 weeks. If there is no improvement at all after 2 weeks, it usually means the medicine does not match the germ, two germs are present together, the feet are still wet every day, or a fungal toenail is acting as the source. See a doctor instead of keep changing medicines on your own.
When are oral medicines needed?
A doctor will consider oral medicine when the fungal infection is the thick-sole type, the severe blister type, or covers a wide area, when it does not clear after finishing the creams, or when fungal toenails are also present. Examples of medicines used:
Terbinafine 250 mg once a day for 2 weeks for the skin of the feet (if there are fungal toenails, about 12 weeks).
Itraconazole 100 mg once a day for 2 weeks, or 200 mg twice a day for 1 week.
Fluconazole 150 mg once a week for 2-6 weeks.
Every oral medicine has cautions about the liver and drug interactions, especially with cholesterol medicines, heart medicines, and some medicines older adults take regularly. The doctor may check liver tests before prescribing. Choosing the medicine and the dose is the doctor's decision after examination, and you should not buy oral antifungals to take on your own. See also fungal toenails, because if the nails are not treated the skin of the feet often gets reinfected.
Why does immersion foot get worse after applying a steroid?
Steroid cream quickly reduces redness and itching, so it seems to improve in the first 2-3 days. But if the cause is a fungus, the steroid suppresses local immunity, so the fungus multiplies and spreads wider. The rash changes its appearance and becomes hard to diagnose, which is called tinea incognito. The same problem is common in ringworm of the skin.
Combination creams containing an antifungal, a steroid and an antibiotic in one tube should also not be used on your own for more than 1-2 weeks, for the same reason. If a doctor prescribes one for a period of heavy inflammation, it is usually for a short time and then changed to an antifungal alone.
Can immersion foot be soaked in potassium permanganate, salt water or vinegar?
Potassium permanganate: Mix with warm water until it is a clear light pink, about 1:10,000 concentration, and soak for 10-15 minutes once or twice a day for 3-5 days. It helps dry soggy skin that is weeping. If mixed so strong that it turns purple, it burns the skin and stains the nails and skin brown, and you should not soak continuously for more than 1 week.
Povidone-iodine wound antiseptic: Used on open or scraped sores to reduce bacteria, but it does not treat fungus, and applying it repeatedly on soggy skin may cause irritation.
Salt water: Normal saline 0.9% wound wash can be used to rinse sores, but soaking in strong salt water for a long time makes soggy skin sting more.
Vinegar: Evidence is limited. If you use it, it must be diluted a lot, and stop right away if it stings. Do not use it on open sores.
Garlic, lemon or alcohol applied directly: Not recommended, because it causes another chemical burn on skin that is already soggy.
The key point is that after every soak you must dry between the toes completely, otherwise the soak just adds moisture.
How many days does immersion foot take to clear?
Skin soggy from water: 3-7 days after the feet are kept dry.
Athlete's foot between the toes: Itching improves in 3-7 days, and the skin clears in 1-4 weeks depending on the medicine (terbinafine 1-2 weeks, azole class 4 weeks).
Thick-sole fungal infection: 4-8 weeks, and many cases need oral medicine.
Gram-negative bacteria: 1-3 weeks when the medicine matches the germ and the feet are dry.
Pitted feet: 2-4 weeks.
Immersion foot (trench foot): Several weeks to several months, depending on the damage to nerves and blood vessels.
If you stop the medicine early because the itching has gone, the fungus often comes back within 1-3 months. Finishing the medicine on schedule matters more than changing medicines often.
Is immersion foot dangerous?
Most cases are not dangerous, but the cracks between the toes are an entry point for streptococcus and staphylococcus bacteria, which can cause cellulitis (infection of the soft tissue) of the leg. Athlete's foot is an important risk factor for cellulitis of the leg, and people who have had repeated cellulitis should also get the fungal infection between the toes cleared.
Groups that need extra care include people with diabetes, people with peripheral vascular disease, people with chronic leg swelling, older adults, and people with weakened immunity. In these groups a small wound on the foot can progress into a chronic ulcer.
Immersion foot in people with diabetes
People with diabetes often have reduced sensation in the feet, so they do not notice a wound getting worse, and wounds heal more slowly than in other people. The practical rules are:
Check the feet and toe webs every day after wading through water. Use a mirror to look at the soles or ask someone at home to help.
Wash the feet with mild soap and clean water and dry between the toes. Do not soak in hot water.
Do not pick, cut or peel soggy skin yourself.
See a doctor within 24 hours if there is a sore, pus, red swelling or an unusual foul smell.
Read more about skin conditions in people with diabetes
What does the doctor test when immersion foot does not clear?
Skin scraping with microscopy for fungus (KOH): The result is ready in a few minutes and confirms that it really is a fungus before medicine is given.
Wood's lamp: Erythrasma glows orange-red. Pseudomonas may glow green.
Culture: For wet, foul-smelling sores or sores with pus, to choose the right antibiotic.
Toenail examination: To look for fungal toenails that act as the source of infection.
Blood sugar test: In people with Candida or frequent repeat infections.
When to see a doctor urgently
The foot is swollen, red, warm and more and more painful, or red streaks spread up the top of the foot and leg.
Fever or chills.
Pus, a deep sore, or skin turning black or dark.
Numb, pale or bluish-dark feet after being soaked for several days.
You have diabetes, kidney disease, vascular disease or weakened immunity, even with a small sore.
You have cared for it yourself for 2 weeks with no improvement, or it comes back several times a year.
How to prevent immersion foot and athlete's foot from coming back
Avoid wading through water for long. If you must, wear rubber boots and take them off as soon as you are out of the water.
Wash the feet with soap and clean water within 30 minutes of contact with dirty water, then dry between the toes one web at a time.
Wear cotton or moisture-wicking socks and change them 1-2 times a day.
Rotate 2 pairs of shoes so that each pair can air dry for 24-48 hours.
Dust antifungal powder, such as miconazole or tolnaftate, in the shoes and between the toes during the rainy season.
Wear sandals in shared bathrooms and at the poolside.
Do not share foot towels, socks or shoes with other people.
Treat fungal toenails at the same time.
Common myths about immersion foot
"Immersion foot needs antifungal right away." Not always true. In the early stage it is skin soggy from water, and what is needed is to make it dry.
"No itching means it is cured, so I can stop the medicine." Not true. The fungus is still in the skin, and you should keep applying for another 1-2 weeks.
"Steroid cream makes it clear faster." It can reduce itching, but if the cause is a fungus it spreads and gets worse.
"Smelly pitted feet are a fungus." Mostly they are bacteria, and antifungal does not help.
"A strong potassium permanganate soak clears it faster." Deep purple burns the skin. Use only a light pink.
Quick summary
Immersion foot is not one disease. It can be separated into at least 8 types, including skin soggy from water, fungus, Candida and bacteria.
The early stage appears within 24-72 hours and clears in 3-7 days when the feet are dry.
Athlete's foot is treated with an antifungal such as terbinafine 1% for 1-2 weeks or clotrimazole 1% for 4 weeks, continued for another 1-2 weeks after it clears.
Wet green foul-smelling sores, pitted feet and brown patches between the toes are bacterial, and antifungal does not help.
Do not apply a steroid on your own when you are not sure it is a fungus.
See a doctor immediately for red swelling that spreads up the leg, fever, pus, numb pale feet, or diabetes.
Frequently asked questions about immersion foot
What medicine should I apply for immersion foot?
It depends on the type. If it is only skin soggy from water, no antifungal is needed yet. Dry the feet and apply zinc oxide cream as a moisture barrier. If it is very itchy and peeling in flakes between the toes, which fits athlete's foot, use an antifungal such as terbinafine 1% cream once or twice a day for 1-2 weeks, or clotrimazole 1% cream twice a day for 4 weeks. If a sore is wet, foul-smelling or has pus, it is usually bacterial and a doctor needs to choose the antibiotic. Look at the active ingredient on the label rather than choosing by brand.
Is immersion foot dangerous?
Most cases are not dangerous and clear when treated as the right type, but the cracks between the toes are an entry point for bacteria that can cause infection of the leg (cellulitis). Signs that need a doctor urgently are a swollen, red, warm foot, red streaks spreading up the leg, fever, pus, or a numb pale foot after being soaked for several days. People with diabetes, older adults and people with vascular disease should see a doctor even if the sore is still small, because foot wounds can progress quickly without being noticed.
How many days does immersion foot take to clear with medicine?
Skin soggy from water usually improves in 3-7 days when the feet are kept dry. For athlete's foot, itching eases within 3-7 days of starting the medicine, but you must keep applying until the course is finished. Terbinafine cream is used for about 1-2 weeks, clotrimazole or miconazole for about 4 weeks, and you should keep applying for another 1-2 weeks after the skin looks clear. If there is no improvement at all after 2 weeks of correct use, see a doctor for a skin scraping to test for fungus.
What stages does immersion foot have?
It can be roughly divided into 3 stages. The first stage is skin soggy from moisture within 1-3 days of soaking, with no germ yet. The second stage is bacteria adding to it, usually on days 3-10, with discharge, pus, pain and a foul smell. The third stage is fungus or athlete's foot, which becomes obvious after 1-2 weeks with strong itching and white scaling between the toes, and can become chronic. In reality these stages can overlap, so the actual symptoms must be considered.
How is immersion foot treated?
The first rule at every stage is to dry the feet, dry between the toes one web at a time, change wet socks, and stop wading through water if you can. Then use the medicine that matches the type: a moisture-barrier cream for skin soggy from water, and an antifungal applied for the full course for fungus. For a wet, weeping sore you may soak in light pink potassium permanganate for 10-15 minutes once or twice a day for 3-5 days and then dry thoroughly. If there is pus or red swelling you need an antibiotic from a doctor. Do not apply a steroid on your own if you are not sure it is not a fungus.
What medicine should I use for macerated toe webs?
Toe webs that are white, soggy, very itchy and peeling in flakes fit athlete's foot. Use an antifungal cream such as terbinafine 1% or clotrimazole 1%, applied thinly about 2 cm beyond the edge of the rash after drying between the toes. If it is soggy and wet, green, strongly foul-smelling, and hurts more than it itches, it is usually Gram-negative bacteria, and antifungal alone does not help. If it is a smooth brown patch, it may be erythrasma, which is treated with a topical antibiotic. For the last two a doctor should confirm first.
Read other skin condition articles at skin conditions article library, and for symptoms on the soles read itchy soles: what causes them
Written by Dr. Patara Voravutinon, Dermatologist · Last reviewed October 15, 2026
The information in this article is general knowledge and is not a diagnosis or an individual prescription. The choice of medicine, strength, duration of use and additional tests are the doctor's judgment after a physical examination. Treatment results vary from person to person.
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