Managing Tinea Pedis: Lessons From Clinical Experience

Approximately 26.5 million people a year are affected with tinea pedis in the U.S., according to the Handbook of Nonprescription Drugs.10 That is close to 10 percent of the population. Seventy percent of people in general will develop some level of tinea during their lifetime. Forty-five percent of the people with tinea pedis will suffer from it in episodes greater than 10 years. It may not be constant, but they will certainly have tinea pedis on and off.
According to the American Podiatric Medical Association, 12 percent of podiatric patients come in with tinea pedis.11 Many doctors say they see a lot more onychomycosis than they see tinea pedis. Well, it’s there. They just don’t see it.
If we look at treatments in general, there is no question there is a place for topical therapy for tinea pedis. I don’t think I’m going to put a patient on oral therapy for a patch the size of a quarter. When there are minor infections and limited areas, I have no problem with the topical therapies. My own favorites are those drugs that usually have a reservoir effect or something where I can use a qd dosage, only because there is an increase in patient compliance. There is no question about the fact that oral therapy is the best way to handle widespread infections. If you have a failure of topical therapy, no matter how small the area, and you are convinced either clinically or by culture that it is a fungus infection, then I have no problem switching to the orals. The patient also has no problem switching to the orals because the topical simply didn’t work.

One of the things I found fascinating is that 7.4 million over-the-counter tinea pedis topical antifungal treatments are recommended by pharmacists every year, according to Pharmacy Times.12 If you go back to that original number of 26.5 million people who have tinea pedis, you are looking at more than 25 percent of those patients who bought a product for their itchy feet at the pharmacy.
What has been fascinating is that all of the drugs that I used a year or two ago can now be bought without a prescription. Other than the fact that the organisms can develop some resistance to them, they are not a whole lot less effective now than they were then. The only thing these people don’t have is the doctor explaining to them how to use the medication properly. Patients tend to believe if a little bit works well, a lot works better. That certainly isn’t true of the topical because you’re increasing the moisture of the skin. Of course, they also think the second it stops itching, it’s gone and it’s not.
Over 1 million econazole prescriptions were written in 2002 for tinea pedis by people who were not podiatrists.13
There were 750,000 non-podiatry prescriptions for ciclopirox cream/suspensions in 2002.13 If you start doing some addition, over 9 million out of the 26.5 million are either being treated by pharmacists or MDs, who are not foot specialists. While there are some MDs who are absolutely wonderful at treating feet, I’ve learned to ask patients if the doctor asks them to take off their shoes when the go in for an exam. You’d be surprised how many people say no.

A Closer Look At The Evolution Of Griseofulvin
Dr. Blass: When I was in school from 1969 to 1973, we were scared of griseofulvin. It was erratic. We didn’t know what it was going to do and fortunately for everybody, the original formulation is no longer available.
Then came the microsize griseofulvin, which we thought was the greatest thing since cream cheese. Then the ultramicrosize griseofulvin came along and this is produced with polyethylene glycol. The crystals become significantly smaller so you are talking about crystals that are one-tenth the diameter of the second generation griseofulvin. This stuff is getting smaller and smaller, and obviously, as we discussed before, dissolves much faster and more completely in stomach acid.14
The ultramicrosize griseofulvin is the third generation of the drug. Given the amount of money that it costs to bring a drug to market today, if there wasn’t a significant benefit with this drug, it just simply would not exist anymore.

A Guide To Precautions And Contraindications
Dr. Blass: Just for the sake of clarity, when I refer to griseofulvin, I’m referring to ultramicrosize griseofulvin. We have talked about blood tests. The blood tests are not required for short-term treatment but one must consider each patient individually. In doing blood tests for the onychomycosis drugs, I’ve picked up two cases of subclinical hepatitis and several other cases of other types of liver damage. It’s not that large a number but it is still something to keep in mind.

If you are going to have the patient on griseofulvin for a long period of time, whether you are treating onychomycosis of the nails or whether you’ve got a resistant fungal infection and you’re sure it’s a fungus but you need more of the drug, then I’m going to do LFTs. Personally, I’m going to do CBCs, too. When this drug was first presented to me in the ‘60s, the CBC was more important than the LFT, at least to the instructors who were talking about it.
You obviously cannot give it without any thought to a patient on coumadin. I may give ultramicrosize griseofulvin to a patient on coumadin, but I also give the patient’s primary care physician a heads-up. I call the primary care physician who is handling the patient’s anticoagulant drug and I say, “Listen, I need to use this drug. It’s going to have an effect on the patient. You’ve got to increase your pro times and be more vigilant during the next 30 to 60 days.” They love me for it. It’s good medicine and it brings them business.
When it comes to patients who may become pregnant, I have a release in my office that I actually paid a malpractice attorney to write up for me. Unless a woman is past child-bearing age or 6 years old or has had a total abdominal hysterectomy, they do not get a prescription for an oral antifungal in my office. If there is any possibility the patient can become pregnant, they do not get a prescription for an oral antifungal. To get the prescription, they must sign a consent that says: “Dr. Blass has explained to me that this drug can produce problems with the fetus. Therefore, I understand that I must be on a foolproof form of birth control during the time I take the drug.” Of course, the half-life is such that I don’t care how long it stays in the keratin. I care clinically but I don’t care for this purpose. Very shortly after finishing the drug, the patient can become pregnant if she would like to.
We touched on the contraindications: hepatocellular failure and porphyria. The drug was definitely a Category C for pregnancy and porphyra. You don’t see a whole lot of that, but it’s something we have to keep in mind.
What I like my patients to understand is that the incident rate per 10,000 patients for griseofulvin is zero in terms of liver injury. There were two studies that looked at the risk of hepatic injuries associated with oral antifungals.2,3
One study compared fluconazole, griseofulvin, itraconazole, ketoconazole and terbinafine.2 The second study compared griseofulvin and ketoconazole.3 Neither of these studies showed any problems with griseofulvin. Zero is my favorite number when it comes to getting into trouble. If you look at blood chemistry changes, the numbers under griseofulvin are zero. There are no cases of overt hepatitis. There are no cases of subclinical hepatitis and that is with equivalent numbers of weeks of therapy.
When it comes down to it, if you have a drug that works and the indication says that’s what it’s for, and it’s cheaper, and you can depend on it, then it doesn’t make a whole lot of sense to use another medication in my practice. Why run those kinds of risks?
Doctors frequently come up to me and say, “In listening to your lecture, it appears that every day you practice as though every patient is potentially going to sue you.” My answer to that is, “Yes. Do you have a problem with that?”
I have been in practice for 30 years and I’ve never been sued. That doesn’t mean that I don’t get my share of bad results and I don’t get my share of unhappy patients. There’s a right and a wrong way to handle a patient, and there’s a right and wrong way to use medications so you are less likely to get into trouble. You do not want an attorney to hand the jury the package inserts and say, “Everybody read this over very closely and see if you see anywhere here that it says that this drug is used for tinea pedis.”

A Different Perspective On The Zaias Study
Dr. Blass: In regard to interdigital tinea pedis, the Zaias study found that the combination of griseofulvin and a topical produced the 89 percent clinically mycological cure whereas the cure rate for griseofulvin alone was 10 percent lower.1 I still believe it has a lot to do with the fact that the patients had to put something between their toes. The fact that they got in there, dried out the moisture and rubbed it a little bit may have been just as effective as what they rubbed it with.

In looking at the three-month follow-up study, we know this stuff is coming back. I think the problem with the Zaias study, in looking at the three-month follow-up, is he didn’t break it down, as we’ve discussed here today, between patients who only had tinea pedis and patients who had tinea pedis and untreated onychomycosis.1 I would love to see what would happen to these bar graphs if you threw out all of the recurrences of tinea pedis of patients who also had onychomycosis. I think your numbers would change significantly.
According to Zaias, there was an 85 percent continued cure at three months with griseofulvin and a topical, and 43 percent with griseofulvin alone.1 This seems low but there could have been a huge number of patients who didn’t use the product properly. I don’t think that was tested. It got better. They stopped using the drug. However, when you stop using the drug, spores of the tinea are still in the skin and they are going to grow again. We really have to have a respect for the aggressiveness of this organism. Of course, the topical only has a 20 percent clinical cure rate. Again, the patient will stop using it, probably for the same reason.
If you look at plantar tinea pedis, griseofulvin has a 90 percent clinical and mycological cure.1 I don’t really need to know a whole lot more about it and that’s why I’m doing less and less cultures as time goes by. After 30 years, if I can recognize a fungus infection, then the fact that I might get a negative culture back is not going to change what I’m going to do. Since griseofulvin is a safe and cost-effective drug for the most part, I can almost make the diagnosis on the basis of the effectiveness of the drug. If griseofulvin clears it up, it was a fungus. If you put a patient on one month of griseofulvin and you’re sure he or she is taking it properly and there are no significant changes, the chances are you’re dealing with something else. Then it may be time for biopsies.
When you look at the three-month follow-up study with plantar tinea pedis, griseofulvin had a 69 percent clinical and mycological cure whereas the topical had a 19 percent cure rate.1 Again, they did not pull out those people who had an additional source for reinfection with the tinea. Therefore, when I speak to people about this drug, I usually ask, “Why would you ever want to use ultramicrosize griseofulvin for a fungus infection?” I think they expect me to give the downside and I don’t. It’s effective. There’s no question about it. It’s safe. You don’t have to worry about hurting people. It’s indicated.

The Compliance Factor:
Suggestions For Improving Foot Hygiene
Dr. Blass: Tinea pedis loves wet environments. There’s no question about it. It’s simple to prove that to patients. You ask when it itches the most and they’re all going to tell you right after the shower or bath or right after they go swimming. If you don’t do something to change the environment in which that foot lives, you are going to have a problem. We are creatures of habit. We get out of the shower or bath. We’re standing on a bath mat. How many of us can get down there and dry between the toes? Some of our patients cannot reach their feet.
We tell them they must start drying between the toes and they only have to do that for the rest of their lives. When they say to me they can’t get down there and reach it, I tell them to set a hair dryer on the medium setting and blow dry their feet when then get out of the shower or bath. One patient told me he didn’t have a hair dryer. I told him to wrap a piece of paper towel around the end of a yardstick with a rubber band, and dry between his toes. I’ve been doing this long enough that I’ll show you a way to dry your toes.

Then you have to keep it dry with a powder. People don’t powder because they shake the powder on and the powder goes all over the place. You walk back into the bedroom and following you are these little white footprints which later become part of the cause of the divorce action. I tell my patients to put the powder in a plastic shoebox. They always ask what kind of powder and I tell them as long as it’s not a cosmetic powder, I don’t care. If they say powders are expensive, I tell them to buy cornstarch and pour the product into the shoebox. Then they should slip it under the bed in the spot where they usually sit to put on their shoes and socks in the morning. We are creatures of habit. We usually sit in the same spot. When they sit down, they will pull the powder box out, put their foot into it and move it around. That powders the whole foot. You put the sock on over the box. Whatever is going to fall off falls back in the box. There is no mess and no fuss.

Pertinent Points About Shoes And Socks
Dr. Blass: Then we turn to shoes. Ideally, people should never wear the same shoes two days in a row. There is a reason why shoes are cold when you put them on in the morning instead of being at room temperature. It is because the moisture has not finished evaporating out of there. My patients work outside in Florida in 95º weather. It may involve construction or roofing. It may be so warm they can fry an egg on that roof. I tell them to bring a change of shoes and socks with them to work and change at lunch. People who are going to get wet are told to bring a change of shoes and socks.
Some people say their shoes are very expensive. I say two pairs will last them longer than twice one pair because you give them a chance to dry out. I like using the spray antiseptics. In Florida, if they don’t want to spray the shoe, I tell them to open the shoe wide up and leave it in the sunshine. Sunshine is pretty good for this. We have this long-term follow-up visit and they ask me how long they have to do that. The answer is forever. I have much lower recurrence rates if the patient develops a better habit of daily foot hygiene.
The last part of foot hygiene is socks. I come from a state where people wear shoes without socks. It’s a shame that tinea pedis is not a better income earner because I see so much of it. When you are dealing with a good drug like this, you are getting an office visit. The lab gets the culture if I run it. Then you get another office visit. However, as I’ve been doing these lectures to people in different areas of the country, I hear the same thing over and over again. Their problem is the patient doesn’t come back. They can’t get follow-ups. They can’t get post-pictures because they can’t get the patient back. I tell them to call them up and ask them why they didn’t come back, or offer them a free visit. Ninety percent of the time, they didn’t come back because the tinea pedis is gone. Why would patients come back and get the second co-pay when the problem is gone?
The last thing I address with them is socks. I like to make things as easy as possible for my patients. I tell them to fill the sink with water and drop two socks in the water. The one that sinks first is the better sock, simply because it’s more absorbent. It’s pulling the fluid out. It gets heavier and sinks.
I believe the combination of drying powder, shoe changes, proper footgear and proper selection of hosiery is important. Teach the patient how to prevent future infections and he cures himself for life.

Treatment Discussion Points
Dr. Joseph: I love the little homespun ideas. There are some interesting concepts there.
Dr. Shin: When you have a patient who has macerated tinea pedis, do you ever find that the powder adds to the irritation?
Dr. Blass: It depends on the powders they use. In between the toes, I almost always tell them to use cornstarch. Most powders are basically a combination of two chemicals, cornstarch and talc. The cornstarch is not irritating but talc is.
Dr. Gupta: What is your recommended dosage and duration for tinea pedis?
Dr. Blass: I use 250 mg bid. I give them 60 with one refill and I want to see them back between three and four weeks so I can tell them whether they need a refill. They are taking two a day for 30 days. If I have a severely thickened plantar surface, then I have several choices. I can put the patient on a debriding agent. If it’s a limited area of hyperkeratosis, I’ll debride it. If I feel the stratum corneum is going to hang around a lot longer than I want it to, then I just go right to the 60 days.
Dr. Gupta: Does your management for plantar tinea pedis differ from when the tinea pedis is interdigital?
Dr. Blass: There is no difference in duration of dosage. It has more to do with having to do something — drying, powdering — between their toes. There is a product, oxiconazole nitrate cream, that is fairly good because it can inhibit the growth of Candida to a certain extent. One comes as a lotion and one comes as a gel. If I’m going to use a combination therapy, I use that. I lean toward the oxiconazole nitrate cream because of the once-a-day dosage. The patient is more likely to apply it. It also has a reservoir effect. Therefore if they miss a day, it’s not going to be important.

Discussing A Shorter Regimen
For Griseofulvin And The Need
For More Evidence
Dr. Gupta: The Zaias study was for three months.1 The regimens we are proposing are theoretically for four to eight weeks. Could it be those cure rates are dependent on the fact that you needed to use griseofulvin for three months because it’s fungistatic?
Dr. Blass: In my practice, I don’t think one patient in 20 has required the third month. Then again, being the conservative physician I am, the second I write that second prescription — remember, the first one allowed one refill — the patients are getting a LFT and a CBC. I don’t care if it’s one in 5,000, if that one in 5,000 is sitting in front of me, that’s not going to make me feel any better if something goes wrong. Obviously, it would be fantastic to run a study of two months versus three months, but the real key is how long it takes for those cells to slough.
Dr. Gupta: I just want to see the data. Don’t get me wrong. I’m willing to go along for the ride. I just want to try and understand the data. You use it all the time but where are the data to show a higher efficacy for two months and even one month?
Dr. Blass: That’s the problem. I think we are more clinically oriented. My data comes from the fact that they get better and don’t get worse. I think I’m using more result-based medicine than evidence-based medicine. Of course, to a certain extent, that is sort of what private practice is all about. My experience has been that less than one in 20 or 30 patients does not clear and stay clear after two months.

Dr. Joseph: I think the question is: Where’s the data set that the four to eight weeks was based on? This is a drug that had a lot of grandfathering because it was approved under much less stringent guidelines than our current antibiotic, antifungal drug guidelines. That is all Dr. Gupta is saying. It is all well and good in private practice. I’ve been there. I’ve practiced for years and I know that this works. However, we are moving toward an evidence basis for a lot of what we do. It is not to tie hands necessarily, but at least to prove the stuff we are doing actually works as opposed to the anecdotal “I know it works.”
Dr. Blass: That’s the viewpoint I’m bringing to the table, namely clinical experience in terms of what we are doing. Keep in mind that I have the worst population in the world when it comes to fungus. My patient base has the worst hygiene and the wettest feet in the warmest environment. You couldn’t ask for a better place to grow fungus than Florida. I learned about larva migrans in school and never saw a case. In Florida, I see a case every two or three weeks.
Dr. Spielfogel: I’m using a lot of ultramicrosize griseofulvin and I agree with you. The results seen by Dr. Blass and I mimic those found in the study done by Kidawa at the Pennsylvania College of Podiatric Medicine.14 The study found that ultramicrosize griseofulvin is effective within 10 weeks or less of treatment time. A major reduction in symptoms like burning, pruritis, fissuring and crusting was achieved by the fourth week.14
Clinically, from my point of view, it is enough time because I’m getting excellent results.

What About Treating Bullous Tinea?
Dr. Gupta: Do we have any data on griseofulvin with bullous tinea? In practical experience, do you use griseofulvin for bullous tinea? How long do you use it for? Does it change your duration?

Dr. Blass: It changes my therapy. It wouldn’t be so much in terms of duration but I would probably go with evaporating wet dressings in order to dry out the area. I may be more aware of the possibility of secondary bacterial infection. I may be running cultures but they may not be fungus cultures, they may be bacterial cultures. I see bullous tinea problems mostly in the diabetic population. First, I want to prevent major damage. I have to clear up what’s open in that skin first. Then I will keep them on the drug and make my decision of how long to work at it, based on the results.
If it takes them a full 60 days, if they get to the last week to clear up, they are staying on it another month. If they clear in four or five weeks and I’ve got three more weeks of the drug on top of it and the bullae is gone and everything is healed up, then I’ll stop using the medication. However, I’ll bring the patient back in two weeks. I do use a lot of things like a Domeboro type of evaporating wet dressing for the bullous tinea. I find it very effective. If you can dry that stuff out, it works better. The patient can’t put his or her shoes on with the dressing. It forces patients to be more aggressive in home care.

References:

1. Zaias N, Battistini F, Gomez-Urcuyo F, et. al. Cutis 1978;22:197-199.

2. Garcia Rodriguez LA, Duque AA, et. al. A cohort study on the risk of acute liver injury among users of ketoconazole and other antifungal drugs. Br J Clin Pharm 1999;48:847-852.

3. Chien, Rong-Nan, et. al. Hepatic injury during ketoconazole therapy in patients with onychomycosis: a controlled cohort study. Hepatology January 1997 103-107.

4. Roujeau JC, Sigurgeirsson B, et. al. Is dermatomycosis of the foot (onychomycosis/tinea pedis) a risk factor in the development of bactericidal cellulitis of the leg? A case-control study. 2003 AAD poster presentation.

5. Gupta AK, Humke S. The prevalence and management of onychomycosis in diabetic patients. Eur J Dermatol 2000;10:379-384. Reference ID: 25

6. Eady EA, Jove JH. Staphylococcus aureus. Curr Opin Infect Dis 16:103-124, 2003.

7. Personal communication with Harvey Lemont, DPM.

8. Leyden JJ. Progression of interdigital infections from simplex to complex. J Am Acad Dermatol 1993 May; 28 (5 Pt 1):S7-S11.

9. Gentles JC, Evans EG. Foot infections in swimming baths. Br Med J 1973 Aug. 4: 3(5874): 260-2.

10. Handbook of Nonprescription Drugs. 12th ed.

11. American Podiatric Medical Association Department of Public Relations 2000 Survey of Attitudes Toward Foot Care.

12. Pharmacy Times, June 2002, OTC Supplement 2002.

13. IMS Health.

14. Bioavailability of Microsized and Ultramicrosized Griseofulvin Products in Man. J Pharmacol and Biopharmacol 1980;8(4):347-362.

15. Kidawa AS. A comparison of Gris-PEG and Fulvicin-U/F in the treatment of tinea pedis. 1981;71:323-327.

16. Ghannom M, et. al. J Am Acad Dermatol 2003;48:189-93.

17. Lobato MN, et. al. Pediatrics 1997;4:551-4.

18. Elewski BE. Tinea capitis: a current perspective. J Am Acad Dermatol 2000;42:1-20.

19. Mackenzie DWR. Hairbrush diagnosis: in detection and eradication of non-fluorescent scalp ringworm. Br Med J1963;ii:363-5.

20. Williams JV, et. al. Pediatrics 1995;96:265-7.

21. Pomerantz AJ, et. al. Arch Pediatr Adolesc Med 1999;153:483-486.

22. Babel DE, Baughman SA. J Am Acad Dermatol 1989;21:1209-12.

23. Martinez-Roig A. Pediatr Infect Dis J 1988;7:37-40.

24. Bennett ML, et. al. Pediatr Dermatol 2000;17(4):304-309.

25. Friedlander SF, et. al. Pediatrics 2002;109(4):602-607.

26. Physicians Desk Reference.

27. Gupta AK, et. al. Efficacy and safety of itraconazole use in children. Dermatol Clin 21 (2003) 521-25.

28. Elewski BE. Int J Dermatol 1997;36:537-41.

29. Gupta AK, et. al. Br J Dermatol 1999;141:304-306.

30. Allen HB. Pediatrics 1982;69:81-83.

31. Greer DL. Intl J Dermatol 2000;39:302-4.

32. Sharma V, et. al. Arch Pediatr Adolesc Med 2001;7:818-821.