Solve the case of red legs: preventing misdiagnosis of cellulitis21st March 2013
Linda Nazarko (2013) Nurse Prescribing 11(2): 62–69
Although red legs can suggest a diagnosis of cellulitis, about 30% of diagnosed cases of cellulitis will be incorrect. This article attempts to lay out the common errors made and guide advanced nurses into making correct diagnoses and avoiding unnecessary antibiotic therapy. Cellulitis is most commonly confused with venous eczema. Other conditions that are commonly misdiagnosed as cellulitis are lymphoedema and lipodermatosclerosis.
What is cellulitis?
Cellulitis is a bacterial infection that spreads through the dermis and subcutaneous tissue. Its main features are:
- It develops rapidly
- It is accompanied by flu-like symptoms and systemic illness with fever, vomiting and malaise
- It normally occurs in one leg (bilateral cellulitis is rare)
- The skin will be red, hot and swollen
- The edge of the redness will be clearly defined and it may extend quickly
- The skin will often have a break, such as a cut or ulcer, where the bacteria could have entered
- The patient may have lymphangitis and enlarged lymph glands.
What is venous eczema?
Venous eczema is a venous disease that affects about 20% of older people (defined as over 70). It is non-infective and affects the lower legs. It occurs when there is increased venous pressure in the legs as a result of damaged valves, which can be caused by carrying extra weight, abdominal tumours, or deep vein thrombosis (DVT).
Venous eczema is difficult to diagnose and is part of a continuum of venous disease which is classified from C0–C4. Venous eczema is classified as C4 established disease and it involves pigmentation changes, often called staining, caused by haemosiderin deposition.
What is lipodermatosclerosis
This is an inflammation of subcutaneous fat that occurs in patients with venous insufficiency. Two-thirds of sufferers are obese. It has an acute and chronic phase, and the acute phase can resemble cellulitis. Symptoms include:
- Hardened, thickened skin
- Increased pigmentation
- Atrophe blanche
- Varicose veins
- The skin feels woody
- The leg may change shape and resemble an inverted champagne bottle
- Feeling generally unwell.
Tests to use when investigating cellulitis
A full blood count will show a raised white cell count and C-reactive proteins. Tests will be normal for patients with venous eczema or lipodermatosclerosis (although in acute stages of lipodermatosclerosis there may be a slightly higher level of white cells). Cellulitis should be treated with antibiotics.
Treating venous eczema and lipodermatosclerosis
Inflammation can be treated with careful use of topical steroids. If there is not a bacterial cause of the inflammation, there is no need for antibiotics. Emollients can be used after acute symptoms have subsided. Patients should be supplied with plenty of emollients and encouraged to ensure that their skin is properly hydrated.
Class 2 below-knee compression hosiery may be suitable for a patient with venous eczema, but should only be used after a full assessment including a Doppler ultrasound.
Advice on weight control may be appropriate and the patient should be encouraged to walk regularly and elevate their legs when sitting. Good skin care should be recommended and the patient should use emulsifying ointment and avoid products that can strip the skin.
The author uses a case report to illustrate the way to correctly diagnose venous eczema. It shows how a diagnosis can be reached by using appropriate assessment and how treatment can employ interdisciplinary solutions. It is important to safeguard against inappropriate diagnoses and the misuse of antibiotic therapy.
Pauline Beldon, Tissue Viability Nurse Consultant, Epsom & St Helier University Hospitals NHS Trust commented:
A valuable paper for many reasons; Nazarko correctly points out that a differential diagnosis is important to prevent the unnecessary use of antibiotic therapy — something which is still prevalent in primary care. Table 2, which differentiates between cellulitis, lipodermatosclerosis and venous eczema, is excellent, guiding the practitioner through appropriate investigation leading to diagnosis. Later in the paper, Nazarko guides the reader towards correct treatment for each condition. I would venture to say this paper should be read by all practice and community nurses — it could save a patient unnecessary treatment, ensure the appropriate treatment and prevent acute hospital admission.