What does it mean if there's a hollow small hole inside a callus on the sole of the foot, and what should be done about it?
Dec 01, 2025
Source: Cainiu Health
Dr. Liu Wenmin
Introduction
In general, hollow small holes within calluses on the soles of the feet may be caused by prolonged friction and pressure, dry skin with accumulated keratin, plantar warts, porokeratosis plantaris (pitted keratolysis), athlete's foot, or other reasons. Depending on the specific situation, improvements can be achieved through daily care, medication, surgical treatment, or other methods. It is important to wear properly fitting shoes and socks in daily life, avoid prolonged walking or standing, keep the feet dry, and thoroughly dry the feet after soaking.
Generally, the presence of hollow small holes within calluses on the soles of the feet may be caused by prolonged friction and pressure, dry skin with keratin buildup, plantar warts, pitted keratolysis, or athlete's foot (tinea pedis). Improvements can be made through daily care, medication, surgical treatment, or other methods depending on the specific situation. Detailed analysis is as follows:
1. Prolonged Friction and Pressure
When the sole is subjected to long-term pressure or friction, the stratum corneum thickens and forms calluses. Localized tissue ischemia and necrosis due to pressure can result in hollow holes. Choose loose, breathable footwear and socks to reduce foot pressure. Soak feet in warm water each night and gently trim the edges of calluses, taking care not to over-trim.
2. Dry Skin and Keratin Buildup
Dry, dehydrated skin leads to abnormal accumulation of keratin, forming calluses. Keratinocytes lacking moisture become loosely adherent, making them prone to forming hollow spaces. Soak feet in warm water for 10 minutes daily, apply a moisturizing cream containing urea to keep the skin hydrated, and regularly exfoliate excess keratin gently.
3. Plantar Warts
Infection of the sole skin by human papillomavirus (HPV) stimulates abnormal proliferation of keratinocytes, resulting in rough plaques. The center may develop black dots or hollow holes due to insufficient blood supply. Topical treatments such as imiquimod cream or fluorouracil ointment may be used under medical guidance. Oral transfer factor solution can also be prescribed. For persistent cases, liquid nitrogen cryotherapy may be performed.
4. Pitted Keratolysis
Bacterial infection causes dissolution of the stratum corneum on the soles, leading to multiple scattered hollow holes, often accompanied by excessive sweating and odor. Follow medical advice to apply topical fusidic acid cream or mupirocin ointment, take oral amoxicillin capsules, keep feet dry, and frequently change into breathable socks and shoes.
5. Athlete’s Foot (Tinea Pedis)
Fungal infection damages the structure of the stratum corneum, causing hollow holes within calluses, commonly associated with itching and scaling. Under medical supervision, topical antifungals such as terbinafine hydrochloride cream or miconazole nitrate cream may be applied, along with oral itraconazole capsules. Avoid sharing footwear or socks with others and maintain clean, dry feet.
In daily life, wear properly fitting shoes and socks and avoid prolonged walking or standing. Keep feet dry and thoroughly dry them after soaking. Promptly address any skin abnormalities; if symptoms worsen or pain develops, seek timely evaluation at a dermatology clinic.
