The technology

InterDry (Coloplast Limited) for treating intertrigo is made of a non-sterile, polyester fabric that wicks away moisture from the skin and allows it to evaporate. It has a polyurethane coating that is designed to reduce skin-to-skin friction and silver within the fabric to provide antibacterial action. The company states the silver can also fight fungi, although evidence to support this is uncertain. According to the instructions for use, each piece of InterDry fabric can be applied for up to 5 days depending on soiling, odour, amount of moisture and general skin condition. It should be removed before bathing. The technology is available in the form of a non-sterile roll (25 cm × 366 cm) or pouch (25 cm × 91 cm). InterDry can be cut to size with clean scissors to cover the affected area. It should be secured to the skin in 1 of several ways: with the skin fold, with skin-friendly tape, or by tucking under clothing.

Innovations

InterDry is designed to target the 3 main factors associated with intertrigo: moisture from perspiration, friction from skin-to-skin contact and the presence of fungi or bacteria. Existing treatment options tend to address only 1 or 2 factors associated with intertrigo. Current treatments, such as antifungal and corticosteroid creams may need to be applied frequently (such as twice daily), whereas InterDry can be left in place for up to 5 days.

Current care pathway

No relevant NICE guidelines for the treatment of intertrigo were identified. Clinical guidance produced by the primary care dermatology society (PCDS) recommends a 3-step approach to the management of intertrigo: prevention and general measures, medical treatment and other treatments.

For prevention, PCDS recommend minimising skin-to-skin friction, reducing heat and moisture around skinfolds and keeping high-risk areas clean and dry. Patients are also advised to wear light, non-constricting, and absorbent clothing and to avoid synthetic fibres. People with obesity are advised to consider weight loss, if possible. The use of absorptive powders, such as talc and cornstarch, are not recommended by PCDS because they can irritate the skin.

Daktacort cream is recommended as a first-line treatment option because it can treat candida and help to reduce inflammation. Short-term use of Trimovate cream should be considered for more substantial inflammation. Further treatment with topical or oral antibiotics, or oral antifungal therapy may be needed and should be guided by results of skin swabs, which aim to identify the organisms present.

Other treatment, such as surgery to remove excess skin, may be needed for patients with moderate-to-severe intertrigo that is difficult to manage.

According to the company, awareness of intertrigo is low among healthcare professionals.

Population, setting and intended user

InterDry is intended to be used for managing intertrigo, a common inflammatory skin condition caused by moisture, heat and friction from skin-to-skin contact. Intertrigo tends to develop in skin folds, most commonly in the groin, under the breast and in the armpits. It can also become infected by fungi (such as Candida or dermatophytes) or bacteria (such as staphylococci, streptococci, Pseudomonas and Proteus, and can include antibiotic-resistant strains such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant Staphylococcus aureus). Symptoms of intertrigo include redness, inflammation and skin erosion, as well as itching or burning, odour and pain. It is more common in people with obesity. Other risk factors include excessive sweating, systemic infection, chronic steroid and antibiotic use, immunosuppression, immobility and diabetes.

The true incidence and prevalence of intertrigo in the UK is currently unknown. European studies report prevalence rates that vary from 6% in hospital patients to 17% in nursing home patients (Mistiaen and van Halm-Walters 2010). Based on the reported prevalence rates across care settings and patient groups, the company estimates that up to 1.2 million patients are susceptible to intertrigo in the UK.

InterDry can be used in any care setting where people have intertrigo. This includes acute care facilities, community hospitals, hospices, care homes and community care. After brief training by a nurse, patients may apply InterDry themselves. The company provides clinical support and application guides for clinicians and patients on the appropriate and practical use of InterDry.

Costs

Technology costs

InterDry is available as a non-sterile pouch or roll. Costs per unit are £43.07 for the 25 cm × 91 cm pouch and £105.95 for the 25 cm × 366 cm roll (excluding VAT). According to the company, the average cost of managing intertrigo with InterDry is estimated as £63.83, assuming a 73% probability that symptoms are resolved within 5 days. This is based on assumed daily nursing treatment times (15 minutes of cleaning and InterDry by a band 5 nurse) from the expert estimates of 4 tissue viability nurses. This includes the use of approximately 14 cm of InterDry per day for each patient.

Costs of standard care

According to the company, the average cost of managing intertrigo with standard care is estimated as £64.15, assuming a 36% probability that symptoms are resolved within 5 days. This takes the efficacy of standard care from a randomised controlled trial of Daktacort in UK primary care and conservatively assumes treatment with Daktacort cream only (20 minutes of cleaning and Daktacort treatment by a band 5 nurse) from expert estimates of 4 tissue viability nurses. However, application twice every day would be more usual. This includes the use of approximately 4 g per day for each patient of Daktacort cream (£2.49/30 g, BNF).

Resource consequences

InterDry is currently being evaluated in 4 NHS trusts. Adopting InterDry would involve an initial cost increase compared with current treatment options. This could be offset if using InterDry allowed quicker healing, leading to subsequent reductions in the use of dressings, antimicrobials and healthcare resources. There is no comparative clinical evidence relating to these outcomes.

Economic data are available on the company website. It consists of an unpublished conference abstract and a master's thesis reporting results from a cost-effectiveness analysis of InterDry compared with standard care (as recommended by PCDS) in a UK community care setting. The analysis used a Markov decision model and was based on 2015 to 2016 costs. The cost-effectiveness model was revised by the company in 2019 and this is available on the website as a report and presentation. The analysis shows an estimated cost saving of £0.32 per patient with InterDry compared with standard care. Because of a lack of quality evidence on InterDry and other existing treatments for intertrigo, the model makes a number of conservative assumptions. It only allows for first-line treatment (InterDry compared with Daktacort cream). The resolution rates for InterDry come from a study of patients with hard-to-treat intertrigo whereas the resolution rates for Daktacort come from a study without severity inclusion criteria. Downstream health benefits gained from faster resolution were not captured. All presented economic data have not been peer reviewed.