Cellulitis

Cellulitis is an acute infection of the dermal and subcutaneous layers of the skin, often occurring after a local skin trauma (Bailey and Kroshinsky, 2011). Cellulitis can affect any part of the skin but is more common in the lower legs.

Cellulitis develops rapidly. The skin is red, hot swollen, tender and may be painful (Santer et al, 2018). There is often a distinct border between normal skin and skin affected by cellulitis. Marking the border with an indelible pen enables the nurse to observe improvement or deterioration. If cellulitis is not treated, it will rapidly progress beyond the marked area.

Enlarged lymph glands in the groin and lymphangitis (red streaking of the skin spreading proximally from the area of cellulitis) may be present. Clinical features of cellulitis include:

• potential to develop fever
• pain
• chills, excessive sweating and feeling unwell
• erythematous, inflamed and clear area of demarcation
• tenderness
• one or a few bullae
• break in skin, ulcers, trauma, athlete's foot implicated
• high white cell count and C-reactive protein, blood culture is usually negative

Cellulitis is a bacterial infection and the bacteria that most commonly cause cellulitis are streptococcus spp. and Staphylococcus aureus. Other bacteria that can cause cellulitis include Gram-negative bacillus spp., Strep. pneumoniae and anaerobes such as pseudomonas spp. (Stevens and Bryant, 2016).

Cellulitis is diagnosed on the basis of clinical findings and history. The person will usually have clinical indications of infection such as:

• fever
• malaise
• nausea
• shivering and rigors
• red sore skin with a clear line of demarcation
• possibly bullae

Enlarged lymph glands in the groin and lymphangitis (red streaking of the skin spreading proximally from the area of cellulitis) may be present. Complications include subcutaneous abscesses, septicaemia, post-streptococcal nephritis and death (David et al, 2011; Levell et al, 2011; Nazarko, 2016).

The person may have a lesion such as a leg ulcer, a cut, or a scratch on the skin, which enabled bacteria to breach the skin’s defences and cause an infection. For example, people who inject drugs are at risk of cellulitis and abscesses (Wright et al, 2020).

Baseline observations of temperature, pulse blood pressure and respirations should be recorded. A full blood count will show raised inflammatory makers

Management and treatment are based on the severity of infection and the presence of any indications of systemic inflammatory response syndrome (Sullivan and de Barra, 2018). People with cellulitis can be divided into four categories (Table 2).

Nursing and Midwifery Council: standards of proficiency for registered nurses

Part 1: Procedures for assessing people’s needs for person-centred care

2.7 undertake a whole body systems assessment including respiratory, circulatory, neurological, musculoskeletal, cardiovascular and skin status

Part 2: Procedures for the planning, provision and management of person-centred nursing care

4. Use evidence-based, best practice approaches for meeting the needs for care and support with hygiene and the maintenance of skin integrity, accurately assessing the person’s capacity for independence and self-care and initiating appropriate interventions

4.1 observe, assess and optimise skin and hygiene status and determine the need for support and intervention

Bailey E, Kroshinsky D. Cellulitis: diagnosis and management. Dermatol Ther. 2011;24(2):229-39. https://doi.org/10.1111/j.1529-8019.2011.01398.x 

David CV, Chira S, Eells SJ et al. Diagnostic accuracy in patients admitted to hospitals with cellulitis. Dermatol Online J. 2011;17(3)

Eron, LJ, Lipsky BA, Low DE et al. Managing skin and soft tissue infections: expert panel recommendations on key decision points. J Antimicrob Chemother. 2003;52(Suppl 1):i3-i17. https://doi.org/10.1093/jac/dkg466 

Levell NJ, Wingfield CG, Garioch JJ. Severe Lower Limb Cellulitis is Best Diagnosed by Dermatologists and Managed with Shared Care between Primary and Secondary Care. Br J Dermatol. 2011;164(6):1326-1328. https://doi.org/10.1111/j.1365-2133.2011.10275.x 

Marwick C, Broomhall J, McCowan C et al. Severity assessment of skin and soft tissue infections: cohort study of management and outcomes for hospitalized patients. J Antimicrob Chemother. 2011;66(2):387-97. https://doi.org/10.1093/jac/dkq362 

National Institute for Health and Care Excellence (NICE). Cellulitis - acute. 2023. https://cks.nice.org.uk/topics/cellulitis-acute/ (accessed 21 November 2023)

Nazarko L. Cellulitis: correct diagnosis and treatment of red legs. Dermatology in practice.