A diabetic foot ulcer (DFU) is an open wound, most commonly on the bottom of the foot, that develops because of the combined effects of diabetes on the nerves and blood vessels. Peripheral neuropathy dulls sensation — a patient may not feel a stone in the shoe, a blister forming, or a callus breaking open. Peripheral arterial disease slows blood flow, so once the wound exists, the tissue lacks the oxygen and nutrients it needs to heal. The result is a wound that often appears painless, opens under a callus, and gets larger over weeks while the patient is unaware.
This is the trap: the wound doesn't hurt, so it doesn't feel urgent. But the longer a DFU stays open, the more ground an infection can gain — and infection in an ischemic foot is a leading path to amputation. Understanding exactly what happens, and when, is the single best motivator to seek prompt care in St. Louis.
The ulcer begins as a break in the outer layer of skin. There may be a callus that lifts to reveal a shallow crater, a blister that has drained, or a small puncture. The wound bed is typically pink or red, with minimal drainage. At this stage, offloading (removing pressure from the wound), basic wound care, and tight glucose control can often heal the wound in 4–8 weeks. This is the easiest stage to treat and the stage where most patients are not in clinic, because the wound doesn't hurt.
Without intervention, the wound deepens. The bed becomes pale yellow (slough — dead tissue) or black (eschar — dried dead tissue). Surrounding callus thickens, trapping drainage beneath it. The wound extends into fat, fascia, and eventually tendon or joint capsule. Foul odor begins. At this stage, healing still happens, but it requires active debridement — the removal of dead tissue — every 1–2 weeks, advanced dressings, and close monitoring. Home care by a wound NP is highly effective.
Once bacteria breach the wound's defenses, local infection develops: increased drainage, warmth, spreading redness, sometimes a low-grade fever. Worse, infection can track along tendons or into bone — this is called osteomyelitis, and it is notoriously difficult to eradicate. Infected DFUs often require oral or IV antibiotics, surgical debridement, and sometimes hospital admission. Without aggressive intervention at this stage, the infection continues deeper.
Deep infection with compromised blood flow produces necrosis — tissue death. When the foot can no longer be salvaged, partial or total amputation becomes medically necessary. This is the outcome every stage of care is designed to prevent. The path from a painless surface wound to amputation can be as short as 3–6 months if the wound is left entirely untreated; even intermittent or poor-quality care lengthens the timeline only modestly.
Clinicians use the Wagner Ulcer Classification System to grade DFU severity. Understanding where a wound sits on this scale helps patients and families ask the right questions:
| Grade | What It Means | Typical Care Setting |
|---|---|---|
| 0 | At-risk foot — intact skin with callus, deformity, or prior ulcer history | Prevention, offloading, home education |
| 1 | Superficial ulcer through the outer skin layers | Home wound care — debridement, dressings, offloading |
| 2 | Deeper ulcer into tendon, joint capsule, or bone — no abscess or bone infection yet | Home wound care with close monitoring; possible wound vac |
| 3 | Deep ulcer with abscess or osteomyelitis (bone infection) | Coordinated care — home NP + podiatrist or vascular surgeon, possible hospital admission |
| 4 | Partial gangrene of the forefoot | Hospital / surgical intervention required |
| 5 | Extensive gangrene of the whole foot | Surgical amputation typically required |
Most patients in St. Louis who call a mobile wound care service are Grade 1 or Grade 2 — the sweet spot where home-based specialist care can reliably heal the wound and prevent progression.
These timelines assume no specialist wound care. Individual outcomes vary based on glycemic control, vascular status, and nutrition — but the general trajectory holds across most untreated cases:
This is not inevitable — it's what tends to happen in the absence of treatment. Every week of structured wound care reduces the risk curve.
Published outcomes on diabetic foot ulcers are sobering, but the pattern is consistent across studies:
The inverse of these numbers is the hopeful part: 80–85% of DFUs can heal without amputation when patients receive consistent, specialist-level wound care. The difference between the 15% that amputate and the 85% that don't is almost entirely about access to care — which is exactly the problem mobile wound care is designed to solve in St. Louis.
The reason DFUs so often go untreated in St. Louis is not that patients don't want care. It's that diabetic patients are often the least able to get to care: neuropathy affects driving; arterial disease affects walking; vision changes from retinopathy affect everything. A "simple" twice-weekly clinic visit becomes logistically impossible.
Mobile wound care inverts the problem. A nurse practitioner with specialty wound training comes to the home, performs the same bedside debridement, applies the same advanced dressings, initiates wound vac therapy when indicated, and documents wound progress with measurements and photographs. Care continuity is maintained — the same clinician sees the wound week after week, catches subtle deterioration, and coordinates referrals to podiatry or vascular surgery when needed. You can learn more about our in-home diabetic foot ulcer treatment in St. Louis.
What mobile wound NPs typically do at a DFU visit:
Our nurse practitioners visit homes and facilities within 24–48 hours. Early, consistent care is the single strongest predictor of healing — and amputation avoidance.
📞 Call (314) 689-1320If you or a family member has an open wound on the foot that is more than a few days old, three actions this week meaningfully change the trajectory:
DFU outcomes are written not at the moment of amputation but in the weeks and months before. Act now.
Continue reading: Signs your pressure ulcer is infected · Does Medicare cover mobile wound care at home in St. Louis?