Interdigital maceration and dermatitis is caused by one or more bacterial, fungal and or yeast organisms. Lack of natural immunity, a weakened immune system, diabetes, peripheral vascular disease, excessive perspiration of the feet, prolonged exposure to warm, moist, dark environments, and physical trauma are predisposing factors.
Diagnostic Strategy
The condition could be caused by several different agents that can be differentiated with a Wood’s light, culture, or punch biopsy.

  1. red = corynea bacteria minitismun = mycins
  2. green = pseudomonas = quinolones
  3. white = psoriasis or candida. Here, one is justified trying empiric Fluconazole. If it resolves = candida, if it doesn't, then likely psoriasis which can later be confirmed by punch biopsy.
  4. PAS = dermatophytes = fungicide and local topical therapy to reduce moisture and maceration.

What to Expect?
What will it Cost ?

10/11/2004    Stuart Leeds, DPM

Interdigital Maceration (Bryan Markinson, DPM, Mike Boxer, DPM)
RE: Interdigital Maceration (Bryan Markinson,
DPM, Mike Boxer, DPM)
From: Stuart Leeds, DPM

Dr. Markinson brings about a very significant and valid point regarding penetrating vis-à-vis chemical debridement of tissue, in order for properly applied local treatment to take place effectually regarding infectious interspace involvement. I have used 40% salicylic acid, left on for three days to perform the same function as Dr. Markinson suggests. It is antifungal and works faster than urea. Followed by 5% acetic acid wet dressing after removing the sal acid dressing. I have found a very high incidence of Pseudomonas infections at the fourth webspace.

This fourth interspace, I have found, is most affected in sports medicine. One will find, roentgenographically, in these instances a short fifth metatarsal. In this case, the medial head of the proximal phalanx of the fifth toe abuts against the lateral base of the fourth toe. It is my opinion that this structural position along with hypermobility of the fifth ray due to hyperpronation results in compression ischemia of the webspace. The end result is a suppressed local “immune system” due to lack of adequate arteriolar profusion. The consequence is the opportunist organisms that take over the local environment of the skin.

If you squeeze the fourth webspace, there is, in most instances, exquisite tenderness. This painful bursitis is the result of the traumatic compression of the toes. To prevent recurrence, instruct the patient to wear proper width sport or dress shoes, use a buttress between the toes, and control the foot with orthotics.

The second point is the issue of white psoriasis as stated by Dr. Boxer. This is a proper term used by podiatrists as well as my professor of dermatology, an N.Y.U. professor as well, who termed it because this site of psoriasis gave a white appearance as a consequence to the maceration. Perhaps a better term for it would be “white” psoriasis of the interspace. I have found that there are times and events where podiatric physicians can teach others in the medical community new nomenclature.

Stuart Leeds, DPM
Coral Gables, FL

10/08/2004    Barry Mullen, DPM, Bryan C. Markinson, DPM

Interdigital Maceration (Mike Boxer, DPM)
RE: Interdigital Maceration (Mike Boxer, DPM)
From: Barry Mullen, DPM, Bryan C. Markinson, DPM

I would just add pseudomonas as an additional organism in the differential (fluoresces green under Wood's light) of infectious etiology.

Barry Mullen, DPM
Hackettstown, NJ

I have two points to add to the discussion of interdigital maceration:

  1. When caused by a dermatophyte infection, treatment with topical agents that normally are very effective sometimes fails because the organisms are thriving underneath the white, thick, and macerated skin, which protects them from the agent. This is why positive dermatophyte culture may also be elusive. Debriding this tissue is painful and causes bleeding. I have found (after personal communication two years ago with James Leyden, MD.) that topical urea, 40% applied directly to the web space nicely debrides this tissue and within two weeks, the macerated tissue is either gone or the infection eradicated entirely. If the infection is not eradicated entirely, the topical antifungal will now work effectively. For this reason, I often have urea applied at night time and the antifungal applied during the day. Try it, you'll like it!
  2. The term "white psoriasis" persists in discussion only amongst podiatrists. In the dermatology world, it is an archaic term, and one which cannot be defined with consistency. In the podiatry world, the term "white psoriasis" exists merely to make residency interviews more torturing. Podiatrists have the impression that in patients with psoriasis, toe web psoriasis, due to maceration, is "white psoriasis." There are five recognized types of psoriasis: plaque, guttate, pustular, erythrodermic, and inverse. No "white psoriasis" is identified. In researching old literature on the subject, "white psoriasis" has indeed been a term used to describe nothing more than what is correctly called erythrasma. This of course, has nothing to do with psoriasis, and as Dr. Boxer states, is a diphtheroid infection. Dermatology nomenclature is bogged down with many such instances.

Bryan C. Markinson, DPM
New York, NY

10/07/2004    Multiple Respondents

Interdigital Maceration
RE: Interdigital Maceration
From: Multiple Respondents

I have found that patients with extreme hyperhidrosis are over-consumers of refined foods and/or suffer from adrenal stress. Cleaning up the diet does wonders (as excessive perspiration represents a discharge of toxins). Analyze your patient’s adrenals as well. Often times you will find adrenal stress which can be moderated in a number of ways depending upon whether they are hyper or hypo- functional.

Bob Kornfeld, DPM
Lake Success, NY

The first line is to determine what is causing the maceration. Is it excessive persperation and what is causing this and then address that issue. Is there an endocrine problem present. Is the patient highly tense and overly perspires. History is important. What kinds of shoes and socks does the patient wear.

Treatments we have used in our office include, separating the digits so that moisture does not build up in the interspaces. Options include gauze or lambs wool. There are foam devices that are also effective. Another remedy that I have had great success with is called "liquid Foot Powder" It is a combination of tea tree oil and baking soda and it is commercially available. It absorbs moisture, changes the PH in the toe interspaces and also kills some of the interdigital fungi. It is available in many stores.

Elliot Udell, DPM
Hicksville, NY

I've now encountered two occasions of severe, desquamating maceration of the digital intertrigenous areas unresponsive to any desiccant, antifungal or other treatment. In both cases, a VDRL was positive and they had secondary syphilis. There is mention of this with a picture in Witkowski/Lemont's book "Color Atlas of Cutaneous Disorders of the Lower Extremities" (Igaku-Shoin, New York, 1993, page 20, under 'Condyloma Lata'), although I've never seen it described anywhere else.

David Secord, DPM
Corpus Christi, TX

For mild cases I use gentian violet q 3 days + cotton webril strips or 2x2 gauze strips QD w/1st application right in the office, so they get the idea. For elderly or diabetic feet, I use GV + lamb's wool strips instead. For moderate cases I add Zeasorb powder. For intertrigo I add tolnaftate drops or or an AF topical.

If you have fissures &/or abrasions, employ a triple combo plus drying wick: clotrimazole 1% or ketoconazole 2% cream + Silvadene 1% + Zeasorb powder + cotton webril cast padding strips.

I always have patients use astringent soaks, mild QD, moderate BID, severe TID --e.g., Domeboro's. It has a real drying action.

William Godfrey DPM
Fort Polk, LA

For treatment to work, the correct diagnosis must first be established. Intertrigos are mainly caused by one of the following: moniliasis, tinea, white psoriasis, erythrasma or just plain old hyperidrosis. Specimens for microscopic examination and fungal culture will help to identify the first two. A Wood's light examination will quickly identify the diphtheroid Corynebacterium minutissimum that causes erythrasma and a careful history and examination of other body locations for signs of psoriasis will help to identify white psoriasis. A biopsy of the skin may be needed for a definitive diagnosis. Some other causes of toe web maceration are condyloma latum and pseudotinea interdigitalis pedum. Direct treatment at the correct diagnosis and the patient should respond.

Mike Boxer, D.P.M.
Woodmere, NY

11/18/2002    David Secord, DPM, Robert Scott Steinberg, DPM

Interdigital Maceration and Tinea Pedis (Norman Wortzman, DPM; Gary

RE: Interdigital Maceration and Tinea Pedis
(Norman Wortzman, DPM; Gary
L. Dockery, DPM; Elliot Udell, DPM
From: David Secord, DPM, Robert Scott Steinberg,

My treatment of choice for intertrigenous maceration is Gentian Violet 1%. Good antimicrobial, good antifungal and good desiccant. I have had one failure with this treatment and after throwing everything short of the kitchen sink at this, I got a VDRL on the woman and it was positive. The maceration was actually secondary syphilis!. Nice picture of this in Drs. Witkowski and Lemont's "Color Atlas of Cutaneous Disorders of the Lower Extremities"

New York, 1993 (ISBN 0-89640-233-9).

David Secord, DPM
Associate Clinical Professor of Medicine,
Christus-Spohn Hospital System-Memorial
Corpus Christi, TX

I hate cotton! OK, let me explain. I am a runner, cyclist, and skier. Cotton against the skin is the kiss of death. It absorbs and HOLDS moisture. If a runner wears cotton socks he WILL get blisters. I am sure you all know this. A while ago it dawned on me that using cotton balls interdigitally would hold moisture against the skin. But if you stretch out a synthetic "cotton" ball and place it interdigitally, it acts as a wick!!!!

Robert Scott Steinberg, DPM
Hoffman Estates, IL

11/15/2002    Gary L. Dockery, DPM, Elliot Udell, DPM

RE: Interdigital Maceration and Tinea Pedis (Norman Wortzman, DPM)

RE: Interdigital Maceration and Tinea Pedis
(Norman Wortzman, DPM)
From: Gary L. Dockery, DPM, Elliot Udell, DPM

I have found that using a chemical debridement agent is helpful in bringing this condition under control. One item is Carmol-40 (40% urea) Gel, which can be painted onto the interdigital areas. It is antibacterial and antifungal as well and will help to remove the dead and macerated interdigital tissues allowing a better surface for other treatments.

Gary L. Dockery, DPM
Seattle, WA

I have had several patients with this problem. Invariably, the problem tends to be in the fourth interspace. The fungi in this case are not the primary culprits. It is the moisture build up caused by tightness in the area. Osteoarthritic changes in the phalangeal bones might contribute to this along with tight shoes. What I have used is liquid Lamisil applied BID to the toe interspace along with the construction of a toe separator. YOu can use one of the moldable putty like substances or you can dispense one of the silipos toe separators. Sometimes a crest pad will also help. For one patient I have her use cotton balls. If all of the toe interspaces are affected than look at the possibility of hyperhydrosis and treat accordingly.

Elliot Udell, DPM
HIcksville, NY

11/14/2002    Norman Wortzman, DPM

Interdigital Maceration and Tinea Pedis
Query: Interdigital Maceration and Tinea Pedis
From: Norman Wortzman, DPM

I have a patient who has a long standing problem with severe interdigital maceration and tinea pedis. At times he has cultured positive for secondary bacterial infection. He has been treated with both topical and oral antifungals, and when needed, antibiotics. He has also been treated with a variety of astringents. I can get his maceration/tinea to improve, but have not been able to resolve it. Does anyone have any suggestions or treatment protocols which may be helpful.

Norman Wortzman, DPM
Boston, MA

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