A pressure ulcer — also called a bed sore, pressure injury, or decubitus ulcer — is a wound caused by sustained pressure on the skin and underlying tissue. Once the skin is broken, the wound becomes an open doorway for bacteria. In a bedbound or chair-bound patient, that doorway often sits against fabric, moisture, and body fluids — exactly the conditions bacteria need to multiply.
Infected pressure ulcers can progress from localized skin infection to cellulitis (deeper tissue infection), osteomyelitis (bone infection), or sepsis (bloodstream infection). Older adults, patients with diabetes, and anyone with a compromised immune system are at especially high risk. Sepsis carries a mortality rate of roughly 30% in elderly patients, which is why catching an infection early is the single most important thing caregivers in St. Louis can do.
The good news: infection almost always announces itself before it becomes catastrophic. The warning signs are visible, specific, and — if you know what to look for — hard to miss.
Pressure ulcers are scored in stages from 1 (intact red skin) through 4 (exposed muscle, tendon, or bone). An infection can occur at any stage, but Stage 2 and above are at highest risk. Watch for these seven signs on every dressing change:
Clear or lightly pink-tinged fluid is normal for a healing wound. Yellow, green, grey, or brown pus — especially if thick or cloudy — indicates bacterial colonization. Sudden increase in drainage volume (a dressing that was dry for days now soaking through) is equally concerning. Bloody drainage that returns after it had stopped can also signal infection.
Healthy wounds do not smell. A persistent foul odor, especially one that remains after the dressing is changed and the wound is cleaned, is a hallmark of bacterial infection. A sweet, fruity odor can indicate Pseudomonas, which often produces a blue-green drainage. Trust your nose — caregivers are usually right when they report a wound "smells bad today."
A thin rim of pink or light red skin at the wound edge is normal. Redness that extends more than 1–2 cm beyond the wound, or that is spreading outward from visit to visit, suggests cellulitis. Try drawing a light pen line at the edge of the redness and checking again in 8–12 hours — if the redness has crossed the line, call a clinician today.
The skin surrounding an infected wound often feels noticeably warmer than nearby unaffected skin. Compare the skin immediately around the wound to skin an inch or two away, using the back of your hand. Unilateral warmth (warm on one side of the body, normal on the other) is particularly suspicious.
Many patients with deep pressure ulcers have neuropathy and cannot reliably feel pain. But when a previously painless wound starts hurting — or a painful wound becomes significantly worse — infection is a likely cause. Watch for non-verbal signs in cognitively impaired patients: grimacing during dressing changes, guarding the area, new restlessness, or refusal to be repositioned.
A temperature above 100.4°F (38°C), new chills, shaking, or a patient who is suddenly confused, lethargic, or refusing food and fluids may be showing systemic infection. In elderly patients, a change in mental status is often the first and only sign of serious infection — even before fever appears. This is always a same-day call.
Healthy pressure ulcers should slowly contract, with granulation tissue (pink, beefy, bumpy) filling the wound bed. A wound that is expanding in width, depth, or surface area despite consistent care is not healing — and infection is one of the most common reasons. If you measure the wound weekly, a 0% improvement over two weeks is a flag; 20% growth is urgent.
Not every concerning finding requires an ER visit, but knowing which tier of response is appropriate can prevent both under-reaction and unnecessary hospital trips.
| What You See | Response Timeline |
|---|---|
| New drainage color, increased exudate, mild odor | Call wound care within 24 hours |
| Spreading redness, warmth, or increasing pain | Call wound care within 24 hours; same-day if rapidly progressing |
| Wound enlarging week over week | Call wound care this week for reassessment |
| Fever ≥ 100.4°F, chills, confusion, lethargy | Same-day evaluation — call 911 or ER if clinically unstable |
| Exposed bone, foul "rotten" odor, necrotic tissue expanding rapidly | Same-day — urgent evaluation required |
| Sudden severe pain, blistering, discoloration spreading hour-by-hour | Call 911 — rule out necrotizing infection |
A mobile wound care nurse practitioner does more than change dressings. During every visit, a Gateway NP performs a structured assessment designed specifically to catch infection early:
Most pressure ulcer infections in St. Louis can be managed at home once identified — topical antimicrobials (silver, iodine, or honey dressings), oral antibiotics ordered through the primary care physician, and more aggressive offloading often bring infection under control within 7–14 days. For deeper infections, we coordinate hospital admission or wound clinic referral. Learn more about our pressure ulcer care in St. Louis.
Once a pressure ulcer exists, you can't prevent it from being a wound — but you can dramatically reduce the chance of it becoming infected. These evidence-based habits should be part of every caregiver's routine:
Our nurse practitioners visit homes and facilities within 24–48 hours. We assess, document, treat infection, and coordinate with the primary care physician — no ER trip required.
📞 Call (314) 689-1320Infection is the difference between a pressure ulcer that heals in weeks and one that leads to hospitalization, surgery, or worse. The seven red flags above are not exotic clinical signs — they are findings any attentive caregiver can spot. When in doubt, call early. A 10-minute phone consultation can tell a clinician whether you need a same-day visit, a scheduled visit this week, or simply reassurance that what you're seeing is normal healing. Submit a referral online or contact our team to get started.
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