infections are ubiquitous diseases that cause considerable morbidity for
patients. They seldom cause serious problems, but their presence often
disfigures the skin, producing intense pruritus and considerable pain. While
nonprescription products seldom cure minor conditions, they can effectively
eliminate the pathogens responsible for several dermatophytic conditions, such
as tinea pedis. However, effecting a cure with nonprescription antifungal
medications is critically dependent on patient adherence to the FDA-approved
dosing regimens. For this reason, pharmacists must be fully knowledgeable of
the various nonprescription tinea pedis treatment options and their
comparative abilities to produce a rapid cure with a minimal number of
The epidermis is composed of five distinct layers. The topmost layer is known
as the horny layer (stratum corneum) and contains highly keratinized, dead
cells. They are continually shed into the environment and replaced by newer
cells ascending slowly from the lower layers. Dermatophytic infections affect
these keratinized cells, as well as nails and hair, and seldom invade deeper,
Humans are subject to
numerous superficial dermatophytic infections, each traditionally named for
the site of the body affected.2 Some are considered self-treatable,
such as tinea pedis (athlete’s foot), tinea corporis (body ringworm), and
tinea cruris (jock itch). However, the U.S. Food and Drug Administration (FDA)
has determined that existing nonprescription antifungal agents cannot treat
others, such as tinea unguium (onychomycosis), tinea manuum (tinea of the
hand), tinea capitis (scalp ringworm), tinea barbae (tinea of the beard and
moustache), tinea versicolor, and tinea nigra.
Tinea infections are widely acknowledged to be one of the major public health
problems throughout the world.1,3 The prevalence of tinea pedis
varies somewhat depending on such factors as the age of the population studied
and its geographic location, but it is increasing throughout the world.3
In a study of Mexican children aged 2 to 12 years, 21% were found to be
symptomatic and to harbor pathogenic dermatophytes, and an additional 7% were
asymptomatic but also carried the organisms.3 Tinea pedis may
affect 15% to 40% of the U.S. population at any one time; at least 70% of the
world’s population will develop it at some time.4-6
Tinea pedis is the most
common of all dermatophyte-induced infections.2 Investigators
carried out a study of patients attending a dermatology department of a
university-affiliated hospital in Monterrey, Mexico.7 All of the
2397 patients had clinical findings indicating the presence of a superficial
dermatophyte. Patients were subjected to the standard diagnostic procedures to
confirm presence of a cutaneous mycosis. A total of 30.2% of the patients were
diagnosed with tinea pedis. Not surprisingly, 25.6% of patients were diagnosed
with tinea unguium, an infection closely allied with tinea pedis. The less
common tineas diagnosed were tinea capitis (18.4% of patients), tinea corporis
(16.4%), and tinea cruris (9.3%).
Etiology/Transmission of Tinea Pedis
It is worth noting that many of the dermatophytes responsible for tineas grow
optimally in skin that is moist and warm.2 This propensity explains
their preference for intertriginous skin. Intertriginous skin is defined as an
area of the skin that is constantly or often in contact with other skin. Thus,
the moist, warm recesses of the groin and foot are natural targets.
The causative agents of
tinea pedis are the keratinophilic cutaneous mycoses. They are classified into
three categories (geophilic, zoophilic, and anthropophilic), depending upon
their origin and preferred growth location.2 Geophilic species are
thought to have been the prototypical organisms from which the others evolved,
living in the upper layers of the soil, subsisting on protein from dead
plants. Eventually, mycologists theorize that the geophilic fungi found
themselves on the skin of animals that had rolled in the soil. Those fungi
developed the ability to eat the stratum corneum of the animal, becoming
zoophilic fungi. Infected animals were domesticated by early humans, and
contact with them transferred the fungi to their bodies, where it developed
the ability to survive on human stratum corneum, becoming anthropophilic. As
most cases of tinea pedis are contracted directly or indirectly from other
humans, the organisms responsible for tinea pedis are classified as
The fungal species most
often found to cause tinea pedis are Trichophyton rubrum (60% of
cases), Trichophyton mentagrophytes (20%), and Epidermophyton
floccosum (10%).5 Less common invaders include Microsporum
canis and Trichophyton tonsurans.
While tinea pedis does not occur to any greater or lesser degree in any
specific racial/ethic group, it does demonstrate several characteristic
The sports/tinea pedis connection has been permanently linked by the term
“athlete’s foot.” One of the reasons for the link between tinea pedis and
sports or recreational activities lies in the harsh work the feet are often
required to carry out. Running and jumping often cause abrasions of the foot.
Soccer, for example, demands that the feet undergo fairly intense and repeated
shocks.8 As a result, the athlete’s feet are seldom free of cuts
and scratches that could harbor an organism.
However, the patient with a
foot abrasion will not contract tinea pedis unless he or she comes into
contact with desquamated skin cells infected with a dermatophyte. Thus, a
primary epidemiological factor is walking barefoot in any area where the
dermatophyte is likely to be found, whether it is carpeted or not.9
Possible locations are saunas, swimming pools, water parks, and shower/bathing
facilities. Fungal contact often happens during sports activities, as most
athletes prepare and shower in shared locker rooms and shower stalls. Thus, a
potential sports-related transmission chain can be hypothesized and used as a
model for other cases of tinea pedis. An athlete with active or subclinical
tinea pedis walks barefoot in a common area, or showers in a common stall. The
next athlete to walk over the infected area may have an abrasion as a result
of the sports activity, allowing the organism to invade the pedal epidermis.
: Any clothing that retains sweat does not allow underlying skin to dry.
Continually moist skin leads to maceration, in which the skin is damaged and
more vulnerable to fungal implantation and growth. This concept leads to an
interesting observation with regard to tinea pedis. In societies where wearing
shoes is not common, tinea pedis is also uncommon. When “civilization”
dictated covering the feet with shoes and socks (especially those made from
synthetic materials), tinea pedis began to become common, especially when the
prevailing climate was warm and humid.3,10
Some groups are more likely
to experience tinea pedis as a result of the sweat-clothing connection.
Athletes’ bodies sweat during and after exertion as a thermoregulatory cooling
response. Athletes usually wear shoes and socks that allow moisture to remain
in contact with the feet. This is a major causal factor in the survival of
implanted tinea pedis organisms.8 The incidence of tinea pedis
increases greatly following wars in tropical areas, as infected soldiers
return to the U.S.10
Tinea pedis is more common in men than women.4,11 Part of the
explanation may lie with the types of footwear considered acceptable in the
workplace. Women’s sandals are considered dress attire, so their feet are
usually less prone to be bathed in moisture than the man in traditional
business dress, requiring socks and shoes that prevent evaporation.12
The age at which tinea pedis occurs is distributed in a unimodal pattern. It
is rare in those aged 10 years and under, becomes more common as the patients
approach their 20s, and peaks in the 20s and early 30s.7 It becomes
steadily less common until patients reach their 60s, when it is again rare.
A young man approaches the pharmacist to request assistance in self-treating
his athletes foot. He is trying out for the football team, and the coach told
them that several of the players had athletes foot last year and cautioned
them to inspect their feet and obtain early treatment to avoid spreading the
condition. Within the last month, the young man has been increasingly troubled
by itching between the fourth and fifth toes. The skin appears dried and
white, but it has now broken open and is very painful. Furthermore, the soles
of the feet are now pruritic.
This patients symptoms seem to imply possible interdigital tinea pedis. If so,
it will likely spread to involve the soles, arches, and heels unless it is
promptly treated. The pharmacist might ask to inspect the feet to ensure that
they do not have features suggestive of a condition requiring referral (e.g.,
bacterial or Candidal infection). If not, the pharmacist may choose a
nonprescription antifungal agent to cure the condition.
The best choice of therapy is one that produces a cure with the shortest
treatment period, such as one week, as opposed to products that cannot cure
unless they are applied for two weeks or four weeks. In addition, the more
convenient a product is to apply, the greater the chances of compliance and
adherence to the dosage regimen. For this reason, a product producing a cure
with only one application daily is preferable to one requiring two
applications daily. This points the pharmacist toward terbinafine gel as the
optimal therapeutic intervention.
The pharmacist should also provide information on prevention of future
episodes. The young man should be cautioned against walking barefoot in the
locker room or shower stalls. He should also be instructed to keep the feet as
clean and dry as possible. With full attention to these tips and others
provided above, he might never suffer another episode of tinea pedis.
A common clinical finding in patients with tinea pedis is the simultaneous
presence of a tinea at another location on the body. This is probably the
result of autoinfection, in which a patient with a tinea fails to take proper
preventive advice and subsequently allows it to reach uninfected skin, hair,
or nails. In one study of infected patients with tinea pedis, 20% also had
nail infection, and 10% also had tinea corporis.7 This finding
underscores the wisdom of heeding the preventive advice and seeking prompt
treatment of an existing tinea infection.
Hyperhidrois is excessive sweating of the feet. Since maceration of the feet
is a major contributing factor to fungal inoculation, survival, and growth, it
should be evident that excessive sweating would predispose to tinea pedis.
Tinea pedis infections exist across a spectrum. Some tinea pedis infections
are subclinical.8 In these cases, the patient is generally unaware
of the infection until a physician carries out a routine examination and
discovers a slight irregularity that is clinically diagnosed as tinea pedis.
Symptomatic tinea pedis is traditionally placed into one of three
classifications (interdigital, moccasin, and vesiculobullous). The categories
are differentiated on the basis of location and appearance.
Interdigital tinea pedis, the most common subtype, is usually caused by
Trichophyton rubrum or by Trichophyton mentagrophytes;
Epidermophyton floccosum may also be the cause.12,13 As the
name implies, interdigital tinea pedis can occur between any of the toes, but
the most frequent site is the interspaces of the fourth and fifth toes.10
This follows the generally observed finding that tinea preferentially invades
intertriginous skin. As one places the foot into socks and shoes, the toes
with the greatest area of overlapping surface contact are usually the fourth
and fifth toes. Thus, the risk of skin damage and maceration is higher in that
The interdigital skin
infected with this type of tinea pedis often appears dried, dead, and white,
with visible peeling. Beneath the peeled area, the skin is reddened. The
patient complains of itching and painful fissures.10
Interdigital tinea pedis
may be the initial implantation point of tinea pedis, and the beginning of a
large-scale tinea foot invasion, spreading outward to cover the other surfaces
of the toes, the soles, arches, and heels.
Interdigital tinea pedis is
subdivided into two subcategories. The less severe is dermatophytosis simplex,
a chronic scaling condition. However, if the patient occludes the web spaces,
Gram-negative organisms can complicate the picture, facilitating the
development of maceration, causing inflammation, and producing a foul odor.
7 This is known as dermatophytosis complex.10
Moccasin tinea pedis is also known as hyperkeratosis tinea pedis, and is
usually caused by Trichophyton rubrum.10 It is diagnosed
when tinea affects the parts of the foot normally covered by a moccasin, such
as the totality of the plantar surfaces (soles and heels), and the sides of
the feet. The lesions are fine, diffuse and hyperkeratotic white scales with a
border that seems to meander randomly like a river’s course.9,10
Underlying skin is pink to red.13 The patient complains that the
affected areas are tender and pruritic. A more severe form can occur, with the
skin fissuring and becoming erythematous, odorous, and inflamed.12
With constant scratching, the patient can transfer tinea to the hand, which is
known as tinea manuum. As many patients have a “dominant” hand they
predominantly use for scratching, tinea manuum may only be unilateral. For
this reason, the condition is often termed, “two-foot, one-hand” disease.”
Moccasin tinea pedis is a
chronic condition that may not respond well to certain topical antifungals.
Quite often, the patient has a concomitant onychomycosis that is the focus for
reinfection; the nail infection must also be treated to halt recurrences.
The vesiculobullous form of tinea pedis is usually a result of poorly treated
or untreated interdigital tinea pedis. The most common causal agent is
Trichophyton mentagrophytes.13 The patient discovers
that the instep and/or sole of the foot have developed vesicles that
occasionally fuse to form large bullae, but more often develop into flat red
macules.9,10 The infection is inflammatory and pruritic.9
It is the least common subtype of tinea pedis, but also the most severe.
If necessary, a physician can carry out a simple test for confirmation of the
presence of tinea pedis. A wet-mount with potassium hydroxide 10% to 20%
followed by direct microscopy reveals the fungal hyphae.2,10 A lab
may also grow fungi on a suitable medium.
Tinea pedis is one of the dermatological conditions that the pharmacist can
assist the patient in treating effectively by selecting the most appropriate
over-the-counter (OTC) product after careful inspection. If the condition’s
manifestations appear to match those previously discussed, the pharmacist
might recommend a course of nonprescription antifungals, suggesting a product
that is maximally convenient for the patient to use and capable of producing a
cure with a minimum number of applications.
Resembling Tinea Pedis:
Several conditions can mimic the appearance of tinea pedis (
TABLE 1). They include fungal infection with Candida albicans
(erosio interdigitalis blastomycetica) or Scytalidium dimidiatum, and
bacterial infection by Corynebacterium minutissimum (erythasma) or
Gram-negative invaders.9-11,14 Bacterial infections are usually
limited to the interdigital spaces; if the infection is due to Gram-negative
organisms, common features include odor, pus, and a yellowish-green color.
The patient may also have
pustular psoriasis.9,11 Psoriatic lesions of the foot usually occur
only over the pressure points, e.g., points of contact between the foot and
shoe, where epidermal abrasion can induce the koebner phenomenon (skin lesions
appearing on a site of trauma). These lesions are symmetrical and have sharp
margins with a flaking, micai-like surface. The patient often has pitted and
thickened toenails, as well as lesions on the scalp, elbows, and knees.11
Dyshidrotic eczema may be
the culprit as well; it is a recurrent noninflammatory eruption that is more
common during warm weather. The patient with dyshidrotic eczema experiences a
sudden onset of symmetrical blisters on the soles (high instep) and sides of
the toes.9,11 The blisters often coalesce and weep upon rupture,
and the skin peels as the condition resolves over a two- to three-week period.
The soles are not reddened and scaly as in tinea pedis. If any of these
problems are possible, the patient should be urged to seek care from a primary
care physician or podiatrist.
Contact dermatitis to
materials in shoes (e.g., rubber insoles, dyes, tanning agents) can also
resemble tinea pedis.11 An important diagnostic parameter of shoe
dermatitis is the presence of normal skin in which the foot is not in contact
with the shoes. In this instance, the area affected is usually the arch,
rather than the highly callused sole; the toe webs are not affected and the
nails will be normal. If the problem is contact dermatitis, the pharmacist
could suggest wearing different shoes and application of hydrocortisone 1%
cream. If this fails to resolve the problem, the patient should seek care from
Conditions Resembling Tinea Pedis9,14
Nontinea fungal infection
Candida albicans and Scytalidium dimidiatum
Usually limited to
Symmetric lesions, over the
pressure points, with sharp margins; involvement of toenail probable
Symmetrical blisters on
soles and side of toes; soles are not red
more common during warm weather
Common location where foot
is in close contact with shoe or
and toe webs seldom affected; nails normal
of Untreated/Poorly Treated Tinea Pedis
Should tinea pedis be improperly or inadequately treated, the patient will
undoubtedly experience a chronic condition. This is because the fungus thrives
only in dead tissues, where some of the body’s most valuable antimicrobial
defenses (e.g., antibodies, phagocytic reactions) are not operative.
Typically, tinea pedis enters a quiescent stage during the cold winter months.
7 However, even though symptoms appear to have abated, the inability of
the body to eradicate it ensures that it will arise again when conditions are
more favorable. Usually, as the ambient temperature rises and the feet begin
to sweat, the organism emerges from dormancy and the symptoms begin anew. It
is common for the chronically infected patient to complain of recurrent tinea
pedis, with the recurrences coinciding with the onset of spring and summer,
and quiet periods being the late fall and winter.
Another common sequelae of poorly or inadequately treated tinea pedis is
transfer to other body sites. Tinea pedis may be the nidus of infection from
which the patient develops tinea unguium, tinea corporis, tinea cruris, tinea
pedis, or any of the other potential dermatophytic cutaneous infections. The
longer the infection is present, the greater the potential for spread to
with an existing tinea infection may experience eruptions at distant sites
that are not caused by the spread of the initial infection.9 This
process is referred to as a dermatophytid or “id” reaction. When patients
develop fungal id infections on the arms, chest, or sides of the fingers, the
toe webs should be closely examined for the presence of a symptomatic or
subclinical infection that must be treated.10
A complication of poorly treated tinea pedis is extension of the dermatophyte
into deeper tissues, possibly resulting from local suppression of lymphocyte
blastogenic response by the dermatophytes.2 Should the tinea invade
subcutaneous tissue, it can produce a subcutaneous abscess and ulceration.
2 This complication is seen in several patient groups (who are more
prone to develop deep abscesses that ulcerate):
patients (an immediate hypersensitivity reaction may hamper development of
diabetes, with decreased ability to perceive the presence of the infection due
At times, foot damage due to a tinea infection (e.g., fissuring of the skin
on the soles or between the toes) may facilitate the growth of a bacterial
superinfection.10 Bacterial infection of the foot due to tinea is a
particularly acute danger to the patient with diabetes, as the majority of
limb amputations in this population can be directly traced to a bacterial foot
infection. For this reason, the patient with diabetes must act quickly to
ensure that the tinea infection is treated appropriately.
Prevention of Tinea
In order to prevent tinea pedis, the patient can focus on the factors that
increase the risk of contracting it, and avoid or eliminate them. For
instance, if anyone in the house has tinea pedis, other household residents
should wear foot protection in the shower and not use towels or wash cloths
that the index patient may have used until they are thoroughly laundered.
Furthermore, a patient with an existing tinea infection elsewhere on the body
should use a different towel on the feet to avoid transfer. Further tips for
prevention will be discussed later in this article.
Referral is Required
The pharmacist should refer the patient to a primary care physician or
podiatrist if there is lack of assurance that the problem is tinea pedis (or
any other minor, self-treatable foot condition). The pharmacist may use the
manifestations previously presented to help recognize tinea pedis.
antifungal product labels contain clear instructions for when the patient
should stop use and see a physician (e.g., if excessive irritation occurs or
if irritation worsens). The packages are also labeled with the duration of
treatment before the patient should expect a cure. While this time period
varies with each specific product, the patient should be aware that
persistence of suspected tinea pedis might indicate that another condition is
the cause of the symptoms and a physician diagnosis should be sought.
Topical antifungals are commonly used to treat tinea pedis. They are available
in several dosage forms, but this fact does not present serious counseling
problems to the pharmacist. The reason is that dosage form is a strong
determinant of efficacy, so that some products are only available in the most
effective dosage form(s). Therefore, choosing a dosage form is not nearly as
important as choosing the best ingredient. A few clues can be gleaned from the
medical literature. Gels are effective in drying moist toe web spaces, and a
newly introduced gel is now the most efficacious dosage form, when available
products are classified by duration of treatment and fewest number of daily
applications required.10 Creams are helpful on dry, scaly,
moccasin-type tinea pedis. Powders are helpful when dusted inside shoes,
although the most effective ingredients are not available in powder form.
One reference suggests that
when applying a topical antifungal, the patient should ensure that the area is
covered, including about an inch beyond the margins of visible infection.2
Another suggests applying the antifungal in a 1.5 to 2.5 inch radius around
the site of itching as soon as pruritus begins.4 Applying the
product beyond the visible sites of infection might boost the success rate and
lower the risk of recurrences. These references suggest that treatment
continue for at least one to two weeks beyond the time that the condition is
apparently cured. During treatment, patients should strive to wear
nonocclusive footwear and alternate shoes daily to allow them a “resting
period” to dry out thoroughly between wearing.12
Therapeutic Options Classified by Duration of Treatment
and Number of Daily Applications
The nonprescription antifungal market has seen several waves of products
appear, each with increasingly compelling advantages to its use (
TABLE 2). Prior to the early 1970s, there was little choice among
effective nonprescription tinea pedis treatments. Undecylenic acid and its
salts was the most effective therapy until tolnaftate was switched from
prescription to OTC in 1971. This was followed by OTC switches of two
imidazoles: miconazole in 1982 and clotrimazole in 1989. These will be
referred to as the first-generation nonprescription antifungals, as they share
important common attributes. (Since the marketing of undecylenic acids and
their salts has been largely discontinued in most top-selling product lines,
they will not be discussed further.) A second generation of products appeared
with the prescription-to-OTC switches of terbinafine in 1999 and butenafine in
2001. The second-generation antifungals shared critical differences when
compared with the first-generation products. A third-generation product with
an important therapeutic advantage over previous agents has also been
Summary of Selected FDA-Approved
Daily Treatments Required
Cruex Cream, Lotrimin AF
All locations; 4 weeks
Cream, powder, spray
liquid, spray powder
Cruex Spray Powder, Desenex
Powder, Lotrimin AF Powder, Micatin Spray Liquid, Neosporin AF Cream
All locations; 4 weeks
Cream, powder, spray
liquid, spray powder
Aftate Spray Liquid,
Lamisil AF Defense Powder, Tinactin Cream and Spray
All locations; 4 weeks
Lotrimin Ultra Cream
Between the toes;
Between the toes; 4 weeks
Cream, solution, spray pump
Lamisil AT Cream, Spray
Between the toes; 1 week.
Bottom and sides of feet; 2 weeks (cream only)
Lamisil AT Gel
Between the toes; 1 week
First-generation antifungals carry labeling stating that they cure athlete’s
foot in patients aged two years and above, without differentiating among the
three common subtypes of tinea pedis. They are also characterized as having
the longest duration of treatment required of any nonprescription antifungals.
This may be caused by their questionable ability or inability to kill the
fungi outright. Tolnaftate may exert fungicidal effects, but it may only be
fungistatic.16 The imidazoles are not fungicidal under any
circumstances. Rather, they are fungistatic, as they only hamper development
of the fungal cell membrane.2 All are labeled as requiring four
weeks of use twice daily for best results. This presents serious problems in
achieving a cure, as the average period of time patients will self treat tinea
pedis is only 7.3 days.17 The only significant therapeutic
difference among the first-generation antifungals is that tolnaftate is proven
effective in preventing recurrences of tinea pedis. However, yearly
recurrences of the same infection, by definition, indicate that the product
chosen the previous year was ineffective in eradicating the fungal invader,
clearly a treatment failure. The patient should be urged to seek a more
effective fungicidal treatment that can prevent the recurrence in the first
antifungals include those containing tolnaftate (e.g., Aftate Spray Liquid,
Lamisil AF Defense Powder, Tinactin Cream and Spray), miconazole (e.g., Cruex
Spray Powder, Desenex Powder, Lotrimin AF Powder, Micatin Spray Liquid,
Neosporin AF Cream), and clotrimazole (e.g., Cruex Cream, Lotrimin AF Cream).
The second-generation antifungals are characterized by a shorter duration of
treatment for tinea pedis and a higher age at which they are safe for
self-use. They are not recommended for use by patients below the age of 12
years. Terbinafine is a fungicidal allylamine antifungal. It is marketed as
Lamisil AT Cream, Spray Pump, and Solution.17 All three dosage
forms cure interdigital tinea pedis if used twice daily for one week. If the
patient has tinea pedis on the bottom and/or sides of the foot (e.g., moccasin
or vesiculobullous varieties), the only dosage form with proven efficacy is
the cream, when used as directed twice daily for two weeks. Butenafine is a
synthetic fungistatic/fungicidal benzylamine antifungal available as Lotrimin
Ultra Cream, which will cure interdigital tinea pedis if used twice daily for
one week or once daily for four weeks.18,19 Its efficacy on the
bottom and sides of the feet is unknown, and it is not allowed to carry an
indication for moccasin or vesiculobullous tinea pedis. Second-generation
agents are not available as powders.
A third-generation antifungal has recently been marketed, Lamisil AT Gel,
containing the fungicidal allylamine terbinafine.20 It will achieve
cure of tinea pedis between the toes in patients aged 12 and above if applied
once daily for only one week (efficacy on the bottom or sides of the foot is
unknown). Its shorter treatment regimen arises from the fact that it is highly
lipophilic and keratophilic and maintains high therapeutic levels in the skin
for an additional seven days after once-daily application for seven
There is a significant
advantage to once-daily application. Products that require twice-daily
application for one week to cure rely on patient diligence in carrying out
these applications. However, the target patient is often a male adolescent
athlete. This group may feel that they have many more pressing matters to
remember (e.g., work,school, dating) than two administrations of a topical
medication. The reality of life is that compliance plummets as the number of
medication administration episodes multiplies.17 A product that
requires two daily applications cannot be fully effective if the patient can
only manage one application most of the time. Thus, any product that produces
a cure for tinea pedis with only one daily application possesses a significant
advantage in patient adherence to the dosage regimen. Finally, increased
adherence to the dosage regimen producing a complete cure is significantly
advantageous in preventing yearly recurrences from the same, poorly treated
Products/Interventions to Avoid
Unfortunately, many Web sites and companies irresponsibly market unproven
remedies for tinea pedis. One promoting an ointment promises to relieve pain
and itching associated with minor skin irritations. Their Web site features
information about tinea pedis, implying that the product is approved for tinea
pedis indication.24 However, the product contains camphor 1.24%,
methyl salicylate, salicylic acid, and benzoic acid (concentrations unlabeled).
25 None of these are proven safe and effective for the treatment of
tinea pedis. Furthermore, the erosive effect of salicylic acid is
counterproductive in tinea pedis and external analgesics such as camphor and
methyl salicylate are contraindicated for use on broken skin, such as that
seen in interdigital tinea pedis.11 Its use could prevent the
patient from purchasing and using a more appropriate antifungal product.
A search of a Web site
featuring popular homeopathic treatments demonstrates other unproven
medications being promoted for tinea pedis. Depending on exactly which
symptoms the patient enters on a purported matching remedy finder, the company
recommends diluted silicea, causticum, or sepia.26-28 None of these
diluted remedies is proven safe or effective when applied to tinea pedis.
Other Web sites promote
such unproven products/ingredients as silver-impregnated antibacterial socks,
methyl sulfonyl methane, white sulfur, benzalkonium chloride, and herbs such
as garlic and tea tree oil.29-32 None of these have been proven
safe and effective as an antifungal, using FDA approval as the ultimate and
well-accepted scientific criterion. When the pharmacist is confronted with
unknown remedies such as these, it is prudent to call a company representative
and ask for copies of correspondence with the FDA demonstrating that the
product is safe and effective. In the absence of such data, it is safe to
assume that the remedy is unproven. These manufacturers often speak vaguely
about “clinical studies,” which they have neglected to provide to the FDA. The
quality of these studies is in question until the FDA issues a ruling after
Some irresponsible Web
sites allow lay people to provide their own unproven home remedies for tinea
pedis. On one such Web site (sponsored by a homeopathic company), people tout
the benefits of such diverse and unproven therapies as application of thuja,
graphite, selenium, rubbing alcohol, and neem oil, as well as urinating on
one’s own feet while showering.33 Patients using these
unproven products, especially those derived from natural substances such as
propolis, risk adverse reactions, including allergic contact dermatitis.34
Educating, Counseling, and Enhancing Adherence
Approaching the Patient:
The pharmacist who wishes to assist patients in treating tinea pedis must
accomplish several tasks. First, he or she must be cognizant of the
condition’s appearance in order to properly triage the patient. Next, the
pharmacist must have a full grasp of the various topical nonprescription
products available. Finally, the pharmacist must not hesitate to approach
patients who appear to be examining the tinea pedis products.
Some pharmacies have
prescription workloads that do not allow the pharmacist to engage in vital
tasks such as counseling on self-care with OTC products. Other pharmacies have
architectural designs that do not allow visualization of the nonprescription
product aisles. In these cases, the pharmacist may choose to walk up and down
the self-care aisles when there is a lull in prescription filling. For
pharmacies that are more conducive to patient counseling on self-care issues,
the pharmacist’s potential to help patients with tinea pedis is enhanced.
The pharmacist can strive
to meet several important informational goals when counseling the patient with
tinea pedis, such as helping the patient choose a product with a simple
application regimen, counseling on prevention of future episodes, and helping
the patient understand why it is critical to avoid unproven products.
Product With Fewest Number of Applications:
When choosing a product for tinea pedis, the pharmacist should keep in mind
that patients will often prematurely discontinue products with a longer
treatment regimen. Thus, a product with a one-week treatment duration would be
preferable to a two- or four-week product. As many patients may be unable to
comply with a twice-daily application regimen, products with only once-daily
application are also more likely to produce a cure.
Prevention of Future Episodes:
Patients should be advised to wear nonocclusive footwear such as sandals as
frequently as possible, but especially in the summer.35 Those who
must wear shoes and socks during the day, such as business professionals,
should be advised to wear cotton socks and leather shoes that “breathe” and
reduce sweating.4,13 They should also change to sandals as soon as
they can and wear them until bedtime. They may also go barefoot as often as
they can around the house (with the exception of diabetic patients with
peripheral neuropathy).4 Socks should be laundered after each
wearing in the hot cycle of the washer and thoroughly dried in the hot cycle
of the dryer before wearing again.4 Athletic shoes also may be
sprayed with disinfectants and/or treated with bleach to destroy fungi.
During the bath or shower,
patients must wash the feet and toes carefully each day.4 Patients
should be taught to dry the feet thoroughly after each bath or shower, paying
closer attention to the interdigital spaces.12 The towels and
washcloths used should be freshly washed. The patient should never use a towel
borrowed from another person or found in a communal bathing/changing room.
4 Furthermore, the towel used to dry the feet should never be used
subsequently to dry the trunk or groin, as tinea can be transferred to those
Patients should also be
advised to wait for 10 to 15 minutes after bathing to don socks and shoes to
help the feet dry. The goal is to have the feet completely dry at all times
other than when bathing.
Patient to Avoid Unproven Products:
When pharmacists are counseling patients about self-treatable conditions,
professional ethics and moral responsibility dictates that they should take
every opportunity to caution the patient against using unproven products. In
the case of tinea pedis, the spectrum of unproven products is wide, consisting
of the almost universally unproven realm of homeopathic products, herbals, and
dietary supplements. It also encompasses numerous home remedies that are
equally unproven and which should likewise be avoided. Rather, the patient
should be urged to choose products with FDA-proven safety and efficacy.
Tinea pedis is a common dermatophytic infection that affects millions
worldwide. There are several types of tinea pedis and numerous conditions that
mimic the infection, thus it is important to properly diagnose it. The
pharmacist who engages patients in self-care counseling regarding
nonprescription products for tinea pedis can educate them on how to avoid
becoming infected, as well as teach them how to avoid recurrences. As a
result, patients will be more likely to choose products that will yield a
complete and rapid cure of the condition, with a high likelihood that they
will adhere to the dosage regimen.
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