INTRODUCTION / NEED FOR STUDY:

Corns are painful, hyperkeratotic lesions of the skin that develop in response to excess pressure on the bony prominences of the feet and toes. They are often seen in athletes and in patient populations exposed to uneven friction from footwear or gait abnormalities, including elderly persons, diabetic patients, and amputees.1 Pathogenesis involves hyperplasia of the epidermis particularly stratum corneum, resulting from mechanical trauma to the skin. Various clinical types of corns include hard, soft, seed, periungual, neurofibrous and neurovascular. The hard corn, which is the most common type, appears as a dry, horny mass of hyperkeratosis with a hard central core. The soft corn results from the absorption of moisture from perspiration and is noted by its characteristic macerated appearance. Its an extremely painful lesion that can develop between any of the toes but most commonly develops between the fourth and fifth toes.

The various treatment options for relief of symptoms in corns include regular paring, use of keratolytics like salicylic acid, use of properly fitting footwear and better foot hygiene. However, soft corns are often difficult to treat.  Applying an antifungal or antibacterial powder and using a toe spacer are additional techniques used to treat soft corns. But results are often unsatisfactory.

Cryotherapy, also known as cryosurgery, is a commonly used in-office procedure for the treatment of a variety of benign and malignant lesions like keloids, viral warts, seborrheic keratosis, actinic keratosis, bowen’s disease, corns and calluses etc. The mechanism of action in cryotherapy can be divided into 3 phases: (1) heat transfer, (2) cell injury, and (3) inflammation. When using the spray cryotherapy technique, the liquid nitrogen is applied directly on the skin, and evaporation (boiling heat transfer) occurs in which the heat in the skin is quickly transferred to the liquid nitrogen. Cell injury occurs during the thaw, after the cell is frozen. The transformation of water to ice concentrates the extracellular solutes and results in an osmotic gradient across the cell membrane, causing further damage. Inflammation is the response to cell death and helps in local cell destruction. By virtue of its property to cause keratinocyte cell death and epidermal sloughing, cryotherapy potentially has a role in the treatment of soft corns.

Very few studies have been conducted to assess the efficacy of various treatment modalities in patients with corns. Recently Akdemir O et al found that tangential excision together with topical cantharidin was a simple, minimally invasive and reliable treatment for calluses and corns.  Although prevalence data in India is not available,  Indian population is more prone to develop corns due to prolonged engagement in wet work, habit of walking bare foot and poor maintenance of  foot hygiene. Till date, there is no published data on corn treatment in Indian context. Hence, we take up this study to find the role of cryotherapy in treating soft corns.

AIMS

To assess the efficacy of liquid nitrogen cryotherapy in the treatment of soft corns.

MATERIALS AND METHODS

Source of data collection

Patients coming to Dermatology OPD, Father Muller Medical College and Hospital, Mangalore with clinical diagnosis of Soft corns

Inclusion criteria-

•Age more than 18 years

•Patients willing to undergo cryotherapy

Exclusion criteria-

•Patients with Diabetes mellitus and Peripheral vascular disease

•Uncooperative patients

Method of data collection

Informed consent will be taken from all patients.

Detailed history taking and clinical examination will be done for each patient and information entered in a proforma.  Cryotherapy will be given with liquid nitrogen spray technique using a spray gun. Two 15- to 20-second freeze-thaw cycles will be given in each treatment session. Four such sessions will be given at an interval of 2 weeks each and any change in the lesions will be noted. Patients will be followed up for 1 month after the last treatment. Patients with secondary fungal or bacterial infection will be treated appropriately before starting cryotherapy.

Sample size

32 (Calculated based on a pilot study comprising of 5 patients)

Study period

One year