The Treatment of Interdigital Maceration in the Foot

Interdigital maceration is a common yet frequently underappreciated
dermatological condition affecting the web spaces between the toes. It is
characterised by the softening, whitening, and breakdown of skin in the interdigital
clefts, typically resulting from prolonged moisture retention. The fourth interdigital
space, between the fourth and fifth toes, is most commonly affected due to its
relatively confined anatomy and reduced air circulation. While often perceived as a
minor complaint, untreated maceration can serve as a portal of entry for bacterial
and fungal pathogens, potentially leading to more serious infections such as
cellulitis or tinea pedis. A thorough understanding of its aetiology, clinical
presentation, and treatment options is therefore essential for clinicians and allied
health practitioners involved in foot care.

Aetiology and Pathophysiology
Maceration occurs when skin is exposed to excessive moisture over a sustained
period. The interdigital spaces of the foot are anatomically predisposed to this
problem, as perspiration and water accumulate in these confined areas. Contributing
factors include hyperhidrosis (excessive sweating), the wearing of occlusive
footwear, prolonged use of synthetic socks, obesity, and occupational exposure to
wet environments. Individuals with diabetes mellitus and peripheral vascular disease
are particularly vulnerable, as impaired circulation and neuropathy can reduce the
skin’s natural resilience. The compromised stratum corneum loses its barrier
integrity, becoming permeable to microorganisms. This creates an ideal environment
for colonisation by bacteria such as Pseudomonas aeruginosa and Staphylococcus
aureus, as well as dermatophyte fungi, most notably Trichophyton rubrum, which is
the principal causative organism in tinea pedis.

Clinical Presentation and Assessment
Clinically, interdigital maceration presents as pale, waterlogged, and often
malodorous skin within the toe web spaces. The affected skin may appear white or
grey, with a characteristic wrinkled or ‘soggy’ texture. In more advanced cases,

fissuring, erosion, and satellite lesions may be observed. Patients commonly report
symptoms of itching, burning, and tenderness, and may note an unpleasant odour
associated with bacterial overgrowth. A comprehensive clinical assessment should
include a detailed history of symptom onset and duration, footwear and occupational
factors, co-morbidities, and any previous treatments. Laboratory investigations,
such as skin swabs for culture and sensitivity, or potassium hydroxide (KOH)
microscopy to identify fungal elements, may be warranted when infection is
suspected or when empirical treatment has failed.

Conservative and First-Line Treatments
The cornerstone of managing interdigital maceration is addressing the
underlying moisture accumulation. Patient education regarding foot hygiene is
essential. Patients should be instructed to wash feet daily with a mild soap, ensuring
thorough drying of all interdigital spaces using a soft towel or even a hair dryer on a
cool setting. The use of moisture-wicking or natural fibre socks, such as those made
from merino wool or cotton, is strongly recommended, as is the selection of
well-ventilated footwear. Silicone or foam toe separators can be invaluable in
mechanically separating the digits, thereby improving airflow and preventing
skin-to-skin moisture trapping. These simple orthotic devices are inexpensive,
widely available, and have been shown to significantly reduce recurrence in
susceptible individuals.
Topical drying agents play an important role in acute management. Aluminium
chloride preparations are commonly employed for their astringent and antiperspirant
properties, reducing localised moisture production. Antifungal powders, such as
those containing miconazole or tolnaftate, serve the dual purpose of absorbing
excess moisture and treating or preventing fungal colonisation. Similarly, plain
talcum powder or zinc oxide preparations can aid in moisture absorption. In cases
where bacterial superinfection is evident, topical antiseptics such as dilute
povidone-iodine soaks or chlorhexidine washes may be applied to reduce the
microbial burden.

Antifungal and Antimicrobial Pharmacotherapy
When fungal infection is confirmed or strongly suspected, targeted antifungal
therapy becomes necessary. Topical azole antifungals, including clotrimazole,
miconazole, and econazole, remain the first-line treatment for tinea pedis associated
with maceration. These agents are applied twice daily for two to four weeks and
have demonstrated high efficacy with a low side-effect profile. Terbinafine cream,
an allylamine antifungal, offers a shorter treatment course of one to two weeks and

has proven particularly effective against dermatophytes. In cases of extensive,
recalcitrant, or recurrent fungal infection, systemic oral antifungal therapy with
terbinafine or itraconazole may be required, typically prescribed under the guidance
of a dermatologist or podiatrist. Where bacterial co-infection is established via
culture, topical antibiotics such as fusidic acid or mupirocin may be prescribed for
localised disease, while systemic antibiotics such as flucloxacillin or cefalexin are
reserved for spreading infections or those in high-risk individuals.

Advanced and Adjunctive Interventions
For patients with persistent or recurrent interdigital maceration despite
conservative and pharmacological management, a number of adjunctive strategies
may be considered. Iontophoresis, a technique that delivers low-level electrical
current to the skin, has been used to manage hyperhidrosis of the feet and may
benefit patients in whom excessive sweating is the primary driver of maceration. In
selected patients, botulinum toxin type A injections into the plantar surface can
provide several months of anhidrosis, significantly reducing moisture accumulation.
Photodynamic therapy and ultraviolet light treatment have been explored in the
management of recalcitrant fungal infections, although evidence for their routine
use remains limited. Podiatric debridement of macerated, devitalised tissue may also
be performed to remove a substrate for microbial growth and to facilitate topical
drug penetration.

Special Populations and Preventive Care
Certain patient populations require particular vigilance in the management of
interdigital maceration. In diabetic patients, even mild maceration can rapidly
progress to ulceration and secondary infection, with potentially limb-threatening
consequences. Routine podiatric review, regular foot inspections, and early
intervention are critical in this cohort. Elderly patients may have reduced manual
dexterity and impaired vision, limiting their ability to self-care; carer involvement and
assistive devices may be necessary. Athletes, particularly swimmers and those
engaged in prolonged exercise, benefit from preventive strategies including
antifungal prophylaxis, rapid post-exercise foot drying, and dedicated sports
footwear with appropriate ventilation.

Interdigital maceration, though often regarded as a benign and self-limiting
condition, carries significant clinical implications when left unaddressed. Effective
treatment is multifaceted, encompassing patient education, meticulous foot hygiene,

moisture management, orthotic adjuncts, and targeted pharmacotherapy. Early
identification of fungal or bacterial superinfection is crucial to guide appropriate
antimicrobial therapy and prevent disease progression. In high-risk individuals, such
as those with diabetes or immunocompromise, proactive management and regular
podiatric surveillance are indispensable. By adopting a comprehensive,
evidence-informed approach, clinicians can achieve favourable outcomes, reduce
recurrence, and substantially improve patients’ quality of life.