Nails and Feet During Chemotherapy: Gentle Care and Infection Protection

Underlying mechanisms

The occurrence of nail changes during systemic therapy is based on the cytotoxic mode of action of the drugs used. Cytostatic agents inhibit cell division to halt the growth of tumour cells. Because the keratinocytes in the nail matrix are among the fastest dividing cells in the human body, the nail organ reacts with extreme sensitivity to these active substances. The matrix is located beneath the proximal nail fold and continuously produces the nail substance. If this cell division is interrupted or damaged, structural defects arise in the maturing keratin.

The pathophysiological mechanisms vary depending on the type of substance used. Taxanes such as docetaxel or paclitaxel frequently cause severe microcirculation disorders in the nail bed. They damage the delicate capillaries, leading to extravasation, subungual haematomas, and ischaemic detachment of the nail plate. Anthracyclines and platinum compounds tend to impair melanocyte activity and keratin synthesis, manifesting as hyperpigmentation and Beau lines (Beau-Reil grooves). Fluoropyrimidines such as capecitabine or 5-fluorouracil preferentially damage the palmoplantar epidermis, a condition known as hand-foot syndrome.

The anatomical structure of the nail unit exacerbates the problem. The nail consists of the hard nail plate, the underlying, highly vascularised nail bed, and the lateral nail folds, known as the sulci. When the nail bed becomes inflamed due to cytostatic agents, the tissue swells within this rigid anatomical space. Pressure increases significantly, causing severe pain. At the same time, the barrier function of the cuticle, the delicate membrane at the base of the nail, diminishes. Pathogens such as bacteria or yeasts can thus penetrate unhindered into the deeper matrix.

In addition, systemic therapy frequently impairs the immune system. A fall in the blood neutrophil count is known as neutropenia. During this phase, even the smallest micro-tear in the skin around the toenail creates a portal of entry for pathogens. The body's immune system is no longer able to effectively contain localised bacterial populations. A minor irritation can develop into an invasive soft tissue infection within a few hours.

Typical signs

Nail changes manifest in a variety of clinical presentations that often intensify as therapy progresses. Among the earliest signs are colour changes in the nail plate, referred to as melanonychia or leukonychia. Dark longitudinal bands, diffuse brownish-grey discolouration, or white transverse lines appear. These discolourations are usually harmless, but they indicate a disturbance in the nail matrix.

Another common symptom is Beau lines (Beau-Reil grooves). These transverse grooves result from a temporary arrest of matrix activity during a cycle of therapy. Since the toenail grows approximately one to two millimetres per month, the timing of the toxic injury can be traced precisely based on the distance between the groove and the nail fold. Following multiple chemotherapy cycles, the nail plate exhibits a characteristic wave-like surface texture.

More serious is onycholysis, the partial or complete detachment of the nail plate from the nail bed. This process usually begins at the free distal margin of the nail and progresses proximally. Beneath the lifted nail, a hollow space forms, which rapidly fills with tissue fluid, wound exudate, or blood. This moist cavity provides ideal micro-ecological conditions for Pseudomonas aeruginosa, a bacterium whose metabolic byproducts cause a characteristic green-blue discolouration of the nail.

Painful inflammation of the nail fold, clinically known as paronychia, occurs particularly often during treatment with EGFR inhibitors or taxanes. The lateral nail fold swells, becomes markedly erythematous, and is extremely sensitive to touch. Over time, exuberant granulation tissue, commonly called proud flesh, can form. This tissue bleeds easily and is prone to persistent secondary infections with Staphylococcus aureus.

These treatment-related damages must be distinguished from true onychomycosis, a dermatophyte fungal infection. While a fungal infection usually progresses slowly, creates crumbly thickenings, and presents asymmetrical involvement, chemotherapy-induced damage typically develops rapidly, affects multiple nails symmetrically, and is accompanied by marked soft tissue inflammation. Precise differentiation is essential to avoid unnecessary administration of antifungal medications.

Factors in daily life

Alongside the primary toxic effects of the medications, everyday physical stresses act as major amplifiers of discomfort. Mechanical strain, involving pressure and friction, is the main factor behind the development of toenail complications. Rigid shoes that are cut too narrowly in the forefoot press the nail plate against the highly sensitive, inflamed nail bed with every step. Microcirculation is further compromised as a result, accelerating onycholysis.

Footwear architecture and sock selection also play a significant role. Synthetic materials foster a warm, moist microclimate inside the shoe. When feet sweat and moisture is not wicked away, the stratum corneum of the sole and nail fold softens. This maceration disrupts the natural skin barrier. Pressure points caused by thick sock seams directly over the toe tips often lead to bloody blisters under the nail plate.

Inappropriate home foot care is a common cause of preventable complications. Trimming toenails with sharp nippers or scissors carries a severe risk of injury when tissue is compromised. Deep cuts into the lateral nail folds to remove supposedly ingrown corners create micro-wounds. In combination with a reduced leukocyte count, even this minor irritation is sufficient to trigger extensive cellulitis.

Another common mistake is the aggressive removal of the cuticle. When the cuticle is pushed back with metal instruments or cut away with blades, the nail loses its natural seal mechanism. Water, soap residue, and pathogens can enter the nail root unimpeded. Similarly, the use of hard brushes or sharp files under the free edge of the nail causes mechanical separation of the compromised nail bed from the plate.

Thermal influences must also not be underestimated. Excessive heat from hot foot baths causes marked vasodilation, which drastically increases swelling and burning of the soles in pre-existing hand-foot syndrome. At the same time, prolonged soaking strips essential lipids from the skin, severely worsening dryness and cracking on the heels.

When medical assessment is necessary

While mild colour changes and a slowed growth rate are typical side effects, certain warning signs require immediate consultation with the treating oncologist or a dermatologist. Concerns regarding infection are fully justified during an immunosuppressive treatment phase, as local foci of infection can rapidly spread systemically.

An absolute red flag is the onset of a fever of 38.0 °C or higher combined with redness, swelling, or pain in the feet. During a neutropenic phase, any fever must be treated as a potential medical emergency. If the lateral nail fold is severely swollen, throbbing, and discharging purulent fluid under light pressure, a swab for pathogen identification and the initiation of targeted antibiotic therapy are required.

Furthermore, rapidly spreading skin redness extending beyond the immediate nail area requires urgent medical evaluation. This could indicate erysipelas or cellulitis. These diffuse soft tissue infections spread along lymphatic pathways and usually require systemic treatment with intravenous antibiotics to prevent severe complications.

Medical advice should also be sought for extensive nail detachment where more than half of the nail has lost contact with the nail bed. Exudates accumulate beneath the loose plate that cannot be cleaned manually. The physician must decide whether portions of the mobile nail plate should be excised under sterile conditions up to healthy tissue to relieve the site of inflammation.

In addition, open, deep rhagades on the heels or toe pads that bleed or ooze despite care should be medically evaluated. In patients with concomitant conditions such as diabetes mellitus or peripheral arterial disease, the risk of infection is heightened further, necessitating close interdisciplinary coordination.

What podiatric treatment can achieve

A podiatry practice offers highly specialized, atraumatic treatment options for cancer patients. The primary objective of podiatric care is to keep tissue pain-free, prevent micro-trauma, and fully support the barrier function of the skin. Prior to any intervention, a thorough medical history is taken, recording the current stage of chemotherapy, blood values, and any co-existing conditions.

In our practice, we work according to the strictest guidelines for hygiene standards. All rotary and manual instruments are cleaned, disinfected, and sterile-packaged through a validated process. For patients undergoing cytostatic therapy, only instruments with extremely fine teeth or special diamond coatings are used. This effectively prevents friction-induced heat generation and reduces pain perception to a minimum.

Treatment of the nail plate is carried out with extreme care. Instead of shortening nails with cutting tools, they are usually gently reduced to an appropriate length using fine diamond burs. Thickened nail plates are cautiously thinned to lower pressure on the sensitive nail bed. Loose nail fragments that have lost contact with tissue during onycholysis are gradually removed to prevent moisture pockets from forming underneath.

When caring for the lateral nail folds, we avoid sharp instruments. The sulcus is gently cleaned using specialized, rounded probes. If the nail fold is irritated, sterile soft-fleece tamponades can be inserted. These act as a protective cushion between the nail edge and inflamed tissue, providing immediate pressure relief and promoting the subsidence of inflammation. Further information on our treatment methods can be found in the overview of our services.

The application of acrylic artificial nails or nail braces is generally avoided during active chemotherapy. Pathogens can multiply undetected beneath artificial nail materials, while rigid braces could exert additional pressure. Instead, podiatry focuses on conservative, skin-sparing pressure relief measures. Soft silicone orthoses can be individually tailored to protect misaligned toes from friction. You can learn more about the qualifications of our practitioners under About me.

Treatment intervals are kept short. A rhythm of three to four weeks is often recommended, coordinated with the chemotherapy cycles. In this way, emerging pressure points or nail changes can be detected and treated early, before painful inflammation develops.

What you can do yourself

Self-care at home plays a critical role in maintaining foot health during medical cancer therapy. However, it requires adapting established care routines toward extremely gentle procedures. Gentleness and consistency are paramount.

• Perform a daily inspection routine. Examine your feet and toenails every day under good lighting. If necessary, use a hand mirror or ask family members for assistance to thoroughly check the soles of your feet and the spaces between your toes. Look for redness, swelling, small cracks, or discolouration.

• Clean gently. Wash your feet daily with lukewarm water. Water temperature should not exceed 36 °C to prevent unnecessary vasodilation. Use mild, soap-free washing lotions with a skin-neutral pH value of 5.5. Avoid prolonged foot baths, as these macerate the skin. Afterwards, pat the feet dry with a soft towel, especially between the toes.

• Specifically strengthen the skin barrier. Apply a dermatological care cream daily. Products containing urea at a concentration of 5 to a maximum of 10 percent provide intense moisture and gently soften mild hyperkeratosis. For very dry skin, lipid-rich ointments with ceramides or panthenol are suitable. Do not apply cream between the toes to prevent moisture accumulation.

• Perform nail care safely. Use only emery boards or glass files to shorten toenails. Always file nails in one direction only and leave the corners slightly rounded so that the nail edge does not grow into the lateral skin fold. Never cut the cuticle and do not use metallic nail cleaners.

• Select footwear carefully. Wear soft, breathable footwear made of leather or mesh material with adequate toe room. Ensure that internal seams do not press against the toes. Socks should consist of natural cotton or beechwood viscose, lack tight elastic bands, and be worn inside out so that the seam does not rub against the toes.

• Protect against extreme temperatures. Protect your feet from cold and heat. Avoid walking barefoot to prevent injuries from small foreign objects. Indoors, always wear soft slippers with a non-slip sole.

Common mistakes

In clinical practice, well-intentioned care measures frequently worsen the problem unintentionally. The most common mistake is cutting out the corners of the nail. As soon as individuals feel slight pressure in the lateral nail fold, they use nail nippers to cut the nail deep within the sulcus. This often leaves behind a sharp keratin spur that pierces deep into the inflamed tissue as it regrows, triggering severe paronychia.

Another serious mistake is the use of aggressive home remedies or highly concentrated foot baths. Baths containing curd soap, chamomile, or high concentrations of salt severely dry out compromised skin. Chamomile also carries a high allergenic potential, which can lead to contact eczema on already irritated skin. Applying over-the-counter wart tinctures or aggressive callus-removing socks is likewise dangerous, as the acids they contain can cause deep chemical burns in tissue damaged by chemotherapy.

Wearing conventional nail polish and using acetone-containing polish removers poses a significant risk. Acetone strips remaining lipids from the nail plate, making it extremely brittle. Furthermore, hard nail polish seals the surface, preventing minor subungual haemorrhages or Pseudomonas infections from being detected early. Specialised water-based protective lacquers should only be used after explicit approval by a podiatrist or physician.

Ignoring early pressure points is equally detrimental. Attempts are often made to compensate for painful areas on the feet by altering gait mechanics. This leads to abnormal loading on the ankle, knee, and hip joints, creating new, painful blisters or hyperkeratosis elsewhere on the sole.

Finally, the regular disinfection of home nail instruments is often neglected. Merely rinsing under hot water is by no means sufficient to kill vegetative bacterial stages or fungal spores. If nail files are shared among family members, cross-infections can easily be transmitted, leading to severe consequences in immunocompromised individuals.

Current research and clinical evidence

In recent years, medical research has paid significantly greater attention to the management of cutaneous and ungual toxicities associated with anti-cancer therapies. In the evidence-based S3 guidelines for supportive care in oncological patients, prophylaxis and early intervention for nail changes are classified as an essential component in maintaining quality of life [1].

Clinical studies demonstrate that the use of regional hypothermia during the infusion of taxanes can significantly reduce the severity of nail toxicities. Wearing cooled gloves and booties (cooling pads) induces local vasoconstriction of the capillaries. Consequently, less cytostatic agent reaches the keratinocytes of the nail matrix during peak drug concentration in the blood [2]. This method reduces the incidence of onycholysis and severe paronychia by up to fifty percent.

Studies on supportive dermatological care also confirm the substantial benefit of topical emollients and barrier-strengthening creams. A multicentre observational study demonstrated that the consistent daily application of preparations containing urea and panthenol significantly reduces the risk of severe grades of hand-foot syndrome [3]. Patient cohorts who initiated structured skin and nail care prior to commencing cytostatic therapy experienced significantly fewer complications that necessitated treatment interruption.

Podiatric prevention concepts are also gaining increasing recognition in professional circles. Systematic recording of patient data revealed that integrating podiatric specialists into the interdisciplinary oncology team noticeably reduces the rate of severe wound infections on the lower extremities [4]. The authors emphasize that atraumatic care and professional pressure relief play a crucial role in enabling planned chemotherapy doses to be delivered without delay-induced dose reductions.

Treatment in Memmingen

For individuals in the Memmingen area, Unterallgäu, Upper Swabia, and the entire Allgäu region, FREITAG® Podologie GmbH provides a highly specialized and empathetic care centre. Our practice is located at Kempterstr. 25 in 87700 Memmingen and is thoroughly equipped to meet the unique needs of oncology patients.

Under the clinical direction of Helga Maria Freitag, state-recognized podiatrist and sectoral practitioner in podiatry (sektorale Heilpraktikerin), we place the highest priority on gentle, risk-free, and pain-free treatment. We understand the anxieties and physical strains associated with medical anti-cancer therapy. Therefore, we take the time for an in-depth consultation and tailor every step of treatment individually to your current state of health.

If you have questions regarding toenail care during chemotherapy or wish to arrange an appointment for preventive foot care, please feel free to contact us directly. We are here as a reliable partner to safeguard your foot health and mobility to the highest degree during this challenging phase.