Cellulitis and Erysipelas Flashcards
What is cellulitis?
Cellulitis is an acute spreading infection of the skin with visually indistinct borders that principally involves the dermis and subcutaneous tissue. It is characterised by redness, swelling, heat, and tenderness, and commonly occurs in an extremity.
Briefly describe the pathophysiology of cellulitis
Cellulitis develops when micro-organisms gain entry to the dermal and subcutaneous tissues via disruptions in the cutaneous barrier. Beta-haemolytic streptococci and Staphylococcus aureus are most commonly implicated as the causative agents of cellulitis.
What are the risk factors for cellulitis?
- Previous episode(s) of cellulitis
- Fissuring of toes or heels
- Due to athlete’s foot, tinea pedis or cracked heels
- Venous disease
- Due to gravitational eczema, leg ulceration and/or lymphoedema
- Injury to skin
- Immunodeficiency
- Immune suppressive medications
- Diabetes
- Chronic kidney disease
- Chronic liver disease
- Obesity
- Pregnancy
- Alcoholism
What bacteria commonly cause cellulitis?
The most common bacteria causing cellulitis are Streptococcus pyogenes (two-thirds of cases) and Staphylococcus aureus (one third).
What are the clinical features of cellulitis?
The first sign of the illness is often feeling unwell, with fever, chills and rigors. This is due to bacteraemia. Systemic symptoms are soon followed by the development of a localised area of painful, red, swollen skin.
Other signs include:
- Dimpled skin (peau d’orange)
- Warmth
- Blistering
- Erosions and ulceration
- Abscess formation
- Purpura: petechiae, ecchymoses, or haemorrhagic bullae
Cellulitis may be associated with lymphangitis and lymphadenitis, which are due to bacteria within lymph vessels and local lymph glands. A red line tracks from the site of infection to nearby tender, swollen lymph glands.
How is cellulitis diagnosed?
The diagnosis of cellulitis is primarily based on clinical features including a physical exam.
Investigations such as FBC, CRP, ESR, urea and electrolytes and blood culture and sensitivities may be ordered.
Name the classification system grading the severity of cellulitis
Eron classification system
Briefly differentiate stage I-IV of cellulitis using the Eron classification system
Class I: there are no signs of systemic toxicity and the person has no uncontrolled comorbidities.
Class II: the person is either systemically unwell or systemically well but with a comorbidity (for example peripheral arterial disease, chronic venous insufficiency, or morbid obesity) which may complicate or delay resolution of infection.
Class III: the person has significant systemic upset, such as acute confusion, tachycardia, tachypnoea, hypotension, or unstable comorbidities that may interfere with a response to treatment, or a limb-threatening infection due to vascular compromise.
Class IV: the person has sepsis or a severe life-threatening infection, such as necrotizing fasciitis.
When does a patient need admitting with cellulitis?
Admit the patient for intravenous antibiotics if they are class 3 or 4. Also consider admission for frail, very young or immunocompromised patients.
What is the first action that needs to be taken in order to monior the spread of cellulitis?
Before treatment, mark the area of cellulitis, if possible. Draw around the extent of the infection with a permanent marker pen for future comparison and to track the spread of infection. This may be difficult in people with lymphoedema as the rash is often blotchy.
What is the antibiotic of choice for treating cellulitis?
Fucloxacillin is very effective against staph infections and also works well against other gram positive cocci.
What antibiotics can be prescribed if the patient is penicillin allergic?
Alternatives:
- Clarithromycin
- Doxycycline
What is the dose of flucloxacillin prescribed in the community?
Prescribe flucloxacillin 500–1000 mg four times daily for 5–7 days.
Briefly describe the treatment of non-severe cellulitis
If there are no signs of systemic illness or extensive infection, patients with mild cellulitis can be treated with oral antibiotics at home, for a minimum of 5–10 days. In some cases, antibiotics are continued until all signs of infection have cleared (redness, pain and swelling), sometimes for several months. Treatment should also include:
- Analgesia to reduce pain
- Adequate water/fluid intake
- Management of co-existing skin conditions like venous eczema or tinea pedi
Briefly describe the treatment of severe cellulitis
More severe cellulitis and systemic symptoms should be treated with fluids, intravenous antibiotics and oxygen.
For patients with severe infection, give intravenous flucloxacillin in the first instance. If flucloxacillin is unsuitable (e.g. patient has a penicillin allergy), give intravenous clarithromycin.
Treatment may be switched to oral antibiotics when the fever has settled, cellulitis has regressed, and CRP is reducing.
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Erysipelas
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Erysipelas
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Erysipelas
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Cellulitis
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Cellulitis
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Cellulitis
