The maintenance and protection of skin and its integrity is one of the major components of nursing care. Yet, wound care in clinical practice continues to be considered a high-cost, complex, inconsistent activity. The treatment and management of wounds is a specialism and requires nurses to attend regular updates and training (Guest et al, 2015).
The wound-healing process follows four distinct phases. These are:
Barriers to wound healing often occur in one of these four stages, consequently delaying the healing process (Mitchell, 2020). Hypergranulation, also called overgranulation, is a common issue in wounds and often inhibits healing. The number of hypergranulation cases in wounds is relatively unknown and limited knowledge of the problem among health professionals can lead to underdiagnosis (Vuolo, 2010). Additionally, the absence of best practice guidance for managing hypergranulation can lead to a disparity in treatment and nursing practice.
Hypergranulation
Granulation tissue forms in the proliferation phase of wound healing (Figure 1). Granulation comprises newly growing capillaries from the base of the wound and leads to the formation of new blood vessels (angiogenesis), which deliver nutrients and oxygen to the healing tissues (Mitchell, 2020). During this phase fibroblasts from the surrounding tissue are activated by growth factors released in the inflammatory phase. These rapidly replicate and produce a collagen-rich matrix that builds strength and elasticity into the wound. Healthy granulation tissue presents as a highly vascular, moist, pink/red tissue that creates the appearance of a red velvety carpet on the bed of the wound (Vuolo, 2010). This is an essential phase of wound healing and, when complete, leads to the maturation phase.
In some wounds, granulation tissue will ‘over grow’ beyond the wound surface. This is commonly known as ‘proud flesh’, ‘hypergranulation’ or ‘overgranulation’. Hypergranulation is defined as an excess of granulation tissue and usually presents in wounds healing by secondary intention (see Box 1).
Unhealthy granulation (hypergranulation) is characterised by dark discolouration of the wound, with raised or swollen tissue (Peate and Stephens, 2019). It bleeds easily and tends to produce higher levels of exudate, inhibiting epithelialisation and increasing the risk of infection. This is because the longer the wound is open, the greater the risk of infection (Vuolo, 2010; Brown, 2019). This protruding, red, friable tissue can be distressing to patients and creates challenges for health professionals. Hypergranulation can inhibit wound closure by creating a barrier to epithelial cells migrating across the wound surface. It has also been suggested that hypergranulation can increase the risk of scar formation by forcing wound edges further apart.
There are several causative and predisposing risk factors for hypergranulation. These relate to three areas: inflammation, occlusion or cellular imbalance and are categorised as three types of hypergranulation (see Box 2;Vuolo, 2010)
Hypergranulation is precipitated by an aberrant inflammatory phase, caused by infection or foreign bodies. The inflammatory phase in wound healing is responsible for vasodilation, allowing white blood cells to migrate into the area and engulf harmful foreign bodies (Peate and Stephens, 2019). Prolonged inflammation caused by infection or fibre irritant can hinder the healing process, increase fluid loss and contribute to hypergranulation. Foreign bodies and/or persistent irritation result in a prolonged inflammatory phase as the body perceives this as a risk to skin integrity (Brown, 2019).
Friction is a physiological risk factor that has been linked with hypergranulation. For example, in patients with suprapubic catheters and/or gastrostomy tubes, frequent rubbing of the tube against the skin can create a persistent inflammatory response, resulting in hypergranulation (McGrath, 2011). Friction or inflammation can also be caused by an allergic reaction to dressing adhesive or the traumatic removal of dressings.
Trauma to the granulation tissue that leads to a pH imbalance can prevent the wound from progressing and cause a relapse back to the inflammation phase of wound healing. Links between occlusive wound dressings and hypergranulation have been made (Falanga, 1988). Overuse of occlusive dressings can influence hypergranulation by creating a hypoxic environment that causes the body to produce more immature blood vessels to compensate (Dealey, 2005). Occlusive dressings are prone to keeping the wound surface wet, causing oedema and swelling in the wound bed. Occlusivity induces cytotoxic effects detrimental to wound healing (van Luyn et al, 1992).
Social risk factors can be a causative factors for hypergranulation; these may include malnutrition. Protein is composed of amino acids, which are essential for tissue repair and regeneration. Any deficiency in protein impacts the formation of granulation tissue (Medlin, 2012). Patients with any type of wound often report difficulties regarding uncertainty around timescales and prognosis, which cause significant psychological distress. Stress stimulates the hypothalamic-pituitary–adrenal (HPA) axis to produce stress hormones (cortisol and catecholamines), which activate a fight or flight response and prolong inflammation (Samele et al, 2018).
Wound assessment
A holistic wound assessment is essential to identify causative and contributory factors, support diagnosis and highlight factors that may contribute to delayed wound healing (Mitchell, 2020). A holistic assessment should include specific questions relating to the patient's health and wellbeing. In addition to a full holistic wound assessment for hypergranulation, nurses should consider the following:
Treatment
The recommended treatment will vary depending on classification of the type of hypergranulation. Wound infections should be treated with topical antimicrobials, and systemic infections treated with oral or intravenous antibiotics as indicated (Vuolo, 2010).
If hypergranulation fails to respond, the use of licensed topical steroids should be considered (McShane and Bellet, 2012; Jaeger et al, 2016). Steroids work by dampening down the inflammatory response (National Institute for Health and Care Excellence (NICE), 2004; Lyman, 2019). However, according to the British National Formulary, topical steroids are not licensed to treat overgranulation, and a cautious approach must be taken after consultation with a wound specialist (Joint Formulary Committee, 2021). Haelan tape is a topical steroid product that has been used for hypergranulation (Johnson, 2007; Oldfield, 2009). More evidence is required to understand whether Haelan tape would be suitable for large areas of hypergranulation that have moderate levels of exudate. Most recent studies on Haelan tape focus on closed wounds and target keloid and hypertrophic scar management (Goutos and Ogawa, 2017) and are therefore not relevant to open wounds.
Historically, caustic products, such as silver nitrate sticks, were used to reduce hypergranulation by burning the tissue. There are several documented disadvantages of using silver nitrate: damage to the periwound area, increased pain, potential tissue necrosis and infection, and it can cause systemic problems if used over a wide area (Jaeger et al, 2016; Brown, 2019). These products are therefore no longer recommended and should only be considered under specialist instruction and local policy guidelines as a last resort when all other treatment options have been tried and failed.
For type 2 hypergranulation, a more permeable dressing type should be considered, such as a film or polyurethane dressing with a higher moisture vapour transmission rate. Some foam dressings improve gaseous exchange at the wound surface and increase vapour loss through the back of the dressing (for full dressing selection guidance see NICE (2016)). For hypergranulating wounds with higher exudate levels, a more absorbent dressing will be required. Ensure that the dressings are secured in such a way that allows for vapour loss (Vuolo, 2010). Whenever possible, apply moderate pressure to the wound without compromising the blood supply. Pressure to the wound may inhibit hypergranulation tissue.
Mechanical removal of hypergranulation is not recommended as this may cause a return to the inflammatory phase. Leaving the wound open is also not recommended. This could lead to cell death through tissue desiccation, which impacts on the healing process.
Summary
Hypergranulation can be caused by several risk factors, triggering a prolonged inflammatory response. Potential physiological, psychological and social factors that influence hypergranulation include infection, friction to the wound region, nutritional deficit and stress.
Topical steroid ointment is a recognised off-licence product for treatment of hypergranulation by dampening down the inflammatory response. Overall, studies seem to support this treatment, but there are limitations in their design (McShane and Bellet, 2012; Jaeger et al, 2016). This calls attention to the dearth of experimental studies on the use of topical steroid products for the treatment of hypergranulation, highlighting the urgent need to examine its safety and efficacy given that this is an off-label use. Staff need to ensure they have the correct knowledge to identify and treat hypergranulation in practice.