Pressure ulcers

What is a pressure ulcer, and how common is it?

A pressure ulcer is damage to the skin and the tissue under it, usually over a bony area or under a medical device¹. It's also called a pressure sore, bedsore or decubitus ulcer². The clinical term is pressure injury, which replaced "ulcer" in a 2016 update to the staging system, so you'll see both names³.

It can look like unbroken skin with redness that stays when pressed, or a blister. At the other end it can be an open ulcer that reaches muscle and bone¹.

Over one in ten adults in hospital have a pressure injury, and most of those that are staged are in the early stages⁴. They also affect people living at home and in long-term care⁵.

What causes pressure ulcers, and who gets them?

They form when sustained pressure on one part of the body interrupts the blood supply to the skin, so the tissue is injured and in time can die⁶. Pressure, shear (a dragging force on the skin) or friction can all cause this². How much harm results depends on how strong the pressure is, how long it lasts and how well the tissue tolerates it¹. They usually form over bony parts such as the heels, elbows, hips and tailbone⁷.

People most likely to get them move less, have reduced feeling or poor circulation, or have fragile skin⁵. Being seriously ill or having a neurological problem, such as a spinal cord injury, also raises the likelihood². Older people and anyone who stays in a bed or chair can develop sores quickly⁸.

Among older people in hospital, being older, being immobile, incontinence, poor nutrition and diabetes are all linked with pressure injuries⁹. These are links, not proof of cause. In adults with a spinal cord injury, the tailbone area is the most common site, followed by the sitting bones and the heel¹⁰.

If someone has urinary or faecal incontinence, it's worth paying particular attention to the skin around the anus and buttocks.

What do pressure ulcers look like, and what can make them serious?

Early on, the skin over a bony area looks red or darker and stays that colour when pressed lightly¹¹. On brown or black skin the patch can look purple or blue⁷. The area may feel warm, hard or spongy, and you may notice pain, tenderness, itching or tingling⁷¹¹. Skin can also look shiny, blistered or bruised, or become cracked⁶. Tissue changes can begin before anything shows on the surface³.

In adults, the tailbone area and the heels are most often affected. The sitting bones are often affected in people who sit a lot, and the hip in people who lie on their side¹. Sources number the stages differently (grades I to IV, or stages 1 to 4), so labels can vary³⁸.

A clinician looks at the skin and weighs up your risk. Guidelines advise a risk assessment, though that advice is weak¹². Formal risk scoring tools haven't been shown to be very accurate⁵, and in a good-quality trial they didn't lower the number of new ulcers compared with a nurse's judgement¹³.

Features that mark an ulcer as more serious

An ulcer can become infected. The infection can spread to the skin (cellulitis), the blood (septicaemia), or muscle and bone (osteomyelitis), and it can be life-threatening⁶. Untreated sores can also lead to an abscess (a collection of pus)⁸. Signs of infection include hot, swollen or red skin (blue or purple on brown or black skin), pus, a high temperature, and severe or worsening pain⁷. Infection that progresses quickly, or doesn't respond to oral antibiotics, can signal deep or spreading infection¹⁴.

Deep or fast-moving damage is also more serious. Examples are several deep ulcers, ulcers that can't be staged, wounds that are getting worse quickly, and lower-leg cellulitis with extensive tissue destruction¹⁵.

Pressure injuries on the feet or Achilles can sit alongside nerve damage (neuropathy), diabetes, infection, deformity, gangrene or weak pulses¹⁴.

Exposed bone in a long-standing ulcer over the tailbone doesn't always mean the bone is infected, and MRI can wrongly suggest it. Bone biopsy is the gold standard for confirming bone infection¹⁶¹⁷.

What helps first?

For people at higher risk, guidelines strongly recommend an advanced static mattress or mattress overlay, a type of pressure-relieving surface¹². This lowers the risk of an ulcer forming; it isn't a treatment for one that's already there. It isn't clear yet how much other preventive measures add beyond usual care¹³.

Everyday steps are sensible alongside this:

• Check your skin at least daily for redness or discolouration⁸.
• Keep skin at the right moisture level. Skin that's too dry or too moist is damaged more easily⁸.
• Keep active and move as much as you can⁶.
• Eat a variety of nutritious foods, including plenty of fruit and vegetables, drink plenty of fluids and avoid smoking⁶.
• Avoid firm massage over bony areas⁶.

Ulcers are generally best managed when they're found early⁷.

What helps if that isn't enough?

When an ulcer is infected or deep, care goes beyond self-care. For an acute soft tissue infection spreading from the ulcer, a short antibiotic course of up to a week may be used. Longer courses add side effects, secondary infections and resistant bacteria without extra benefit¹⁷. If bone infection is suspected, antibiotics are usually held until a bone biopsy (a small sample of bone) is done, unless there's sepsis or another urgent reason¹⁷.

Deep or fast-moving wounds are the kind a wound-care team gets involved with. Cellulitis with extensive tissue destruction can need debridement (removal of damaged tissue)¹⁵. For a pressure injury on the foot or Achilles, care includes checking for the conditions listed above, and a high-risk foot service may be involved¹⁴.

What affects recovery, and how can I stop it coming back?

A stage number isn't a fixed path. Pressure injuries don't reliably move in a straight line from stage 1 to stage 4: a stage 3 didn't necessarily start as a stage 1, and a stage 1 won't inevitably become a stage 4³. How long healing takes isn't clear yet, so a new skin change over a bony area counts whatever its stage.

The steps above are also what help keep pressure ulcers from coming back: a pressure-relieving surface if you're at higher risk¹², daily skin checks, staying active, eating well and keeping skin neither too dry nor too moist. Formal risk assessment is advised, but it isn't clear that using risk tools lowers the number of new ulcers¹²¹³.