Topical oxygen therapy (TOT) is built on a simple premise: if tissues within a wound are oxygen-deprived, increasing local oxygen availability may support repair. In this approach, oxygen is delivered directly to the wound surface and diffuses into the tissues [1].

Why oxygen matters in wound healing

Oxygen plays multiple roles in wound healing, acting in immune defense, microcirculatory regulation, and extracellular matrix formation. It is essential for intracellular processes and particularly important for antimicrobial activity: neutrophils and macrophages use oxygen to generate reactive oxygen species during the respiratory burst, helping clear bacteria and cellular debris. Oxygen also supports angiogenesis and influences collagen formation, as oxygen-dependent enzymes are involved in fiber synthesis and cross-linking, ultimately affecting tissue strength and organization [2].

From a practical standpoint, oxygen is effective only if it can reach the wound. Delivery occurs along a partial pressure gradient: higher oxygen concentration at the wound surface and favorable diffusion conditions lead to more predictable increases in oxygen availability in superficial tissues.

Indications: when TOT is used as an adjunct

TOT is considered an adjunctive option in patients with chronic wounds that do not heal despite standard care. This includes diabetic ulcers, vascular ulcers, pressure injuries, postoperative wounds with infection, post-amputation wounds (including infected stumps), skin graft sites, ischemic tissues, burns, and frostbite.

A starting point in treatment planning is the assessment of the arterial blood supply. For chronic lower extremity wounds, ankle-brachial index screening is recommended, with referral to a vascular specialist if arterial insufficiency is suspected. If revascularization is indicated, it should be performed before introducing adjunctive therapies, including oxygen-based approaches.

Contraindications and limitations

Only a few strict contraindications are described for modern systems. However, the method is not used in the presence of malignancy within the wound area or in untreated severe ischemia with critically reduced blood supply.

The effectiveness of TOT depends on several key conditions.

First, proper wound bed preparation. Necrotic tissue (eschar, fibrin) creates a physical barrier, preventing oxygen from reaching viable tissue.

Second, unobstructed contact between oxygen and the wound surface. Petrolatum-based ointments may impair diffusion.

Third, a moist environment. Dry, non-humidified gas can desiccate the wound surface, negatively affecting both oxygen transfer and patient comfort.

Oxygen delivery: understanding different technologies

In clinical practice, differences between technologies come down to how oxygen reaches the tissue and how long delivery is maintained.

Hyperbaric oxygenation is a systemic method: oxygen is inhaled through the lungs and then transported via the bloodstream, making local perfusion a critical determinant of effectiveness.

In contrast, topical approaches deliver oxygen directly to the wound surface, where it diffuses into the tissue, reducing reliance on microcirculation as the sole delivery route to the wound bed.

Three main classes of topical gaseous systems are described:

• Topical oxygen (TO, topical oxygen) — intermittent systems in which oxygen (usually from a concentrator) is delivered into a sealed chamber or enclosed space around the wound area. During treatment, dressings are removed, and the wound is maintained in a moist environment; humidification is important to prevent drying.
• Transcutaneous oxygen therapy (TCOT, transcutaneous oxygen therapy) — wearable single-use electrochemical generators that deliver oxygen under a dressing via tubing. Proper operating conditions (including adequate moisture) and pressure offloading (reducing pressure and friction on the wound) are essential in practice.
• Continuous diffusion of oxygen (CDO, continuous diffusion of oxygen) — wearable systems that provide continuous oxygen delivery, often using distribution components to enhance uniform exposure across the wound bed. Some versions include integrated oxygen dressings and flow or pressure control features.

Why monitoring matters

TOT is generally considered safe, but its effectiveness depends on ongoing monitoring.

At a minimum, four areas require attention:

• the wound itself (size, depth, exudate, pain, signs of infection);
• wound bed preparation (adequate debridement, absence of necrosis, maintained moisture, no diffusion barriers);
• vascular status (identifying arterial insufficiency requiring correction);
• device performance (adherence to protocol, effective pressure offloading, proper functioning).

When these elements are addressed, TOT becomes a practical tool in the comprehensive management of chronic wounds. Evidence from a randomized, double-masked study of continuous oxygen diffusion in diabetic foot ulcers demonstrates higher healing rates and faster closure than with a placebo device under identical standard care conditions [3].

Note

The described effects of topical oxygen therapy apply specifically to wound conditions characterized by hypoxia and impaired healing mechanisms. For intact skin, where barrier function is preserved, and tissues are not oxygen-deprived, no clinical need for this therapy has been described. Therefore, TOT should be viewed primarily as a tool for managing chronic and complex wounds rather than a universal approach for healthy skin.

References

1. Oropallo A., Andersen C.A. Topical oxygen. StatPearls [Internet]. 2026.
2. Sen C.K. Wound healing essentials: let there be oxygen. Wound Repair Regen. 2009; 17(1): 1–18.
3. Niederauer M.Q., Michalek J.E., Liu Q. et al. Continuous diffusion of oxygen improves diabetic foot ulcer healing when compared with a placebo control: a randomised, double-blind, multicentre study. J Wound Care. 2018; 27(Sup9): S30–S45.