Cellulitis is an inflammatory skin condition caused by acute infection of the dermal and subcutaneous layers of the skin. (Clinical Resource Efficiency Support Team [CREST], 2005; Atkins, 2016; BLS/LSN, 2022). It is characterised by a superficial, diffuse, spreading skin infection without an underlying collection of pus. Any breach in skin integrity can allow bacteria to enter the skin and cause infection, which can then spread, leading to cellulitis (CREST, 2005; Atkins, 2016).

If left untreated, the spreading infection may become life-threatening. Therefore, it is important that clinicians are aware of the signs and symptoms of cellulitis. The most common infective organisms in adults are streptococcus pyogenes and staphylococcus aureus (CKS NICE, 2023), and this may be caused by any break in the skin such as a bite, scratch, trauma, leg ulcer, or dry, broken skin. Fungal infections such as athlete’s foot may be attributed to the development of cellulitis (Beldon, 2011).

Cellulitis presents as the acute and progressive onset of a red, painful, hot, swollen and tender area of skin. The edge or border of the inflammation may be clearly demarcated (outlined) with blistering (erysipelas) or even superficial bleeding into blisters, which may cause ulceration if left untreated (Beldon, 2011; Sutherland & Parent, 2017). Lymphangitis and lymphadenopathy may also occur (CREST, 2005).

The onset of cellulitis symptoms can vary greatly. It can be over a few hours or even days and occurs as a result of infection. The patient will demonstrate the signs of infection which include:

  • Pyrexia
  • Malaise/fever
  • Pain
  • Tenderness
  • Acute inflammation/erythema
  • Oedema
  • Flu like symptoms - such as fever, malaise, nausea, shivering, and rigors

These can accompany or precede skin changes.

(Beldon, 2011; Sutherland & Parent, 2017; CKS NICE, 2023)

The lower limb is the most common site of infection and usually affects one limb (a bilateral leg cellulitis is very rare. However, cellulitis may occur on any part of the body but most commonly the arms, face and periorbital area. (CREST, 2005; CKS NICE, 2023)