Cellulitis Flashcards
What is cellulitis?
Cellulitis is an acute bacterial infection of the dermis and subcutaneous tissue.
What is erysipelas?
Erysipelas is a distinct form of superficial cellulitis with notable lymphatic involvement. It is raised and sharply demarcated from uninvolved skin.
What are the most common organisms causing cellulitis?
- Streptococcus pyogenes
- Staphylococcus aureus
What are the risk factors for cellulitis?
- Trauma (due to a bite, burn, or laceration)
- Leg ulceration, maceration or fungal infection between the toes
- Concomitant skin disorder (such as atopic eczema)
- Lymphoedema
- Leg oedema
- Venous insufficiency and history of venous surgery
- Obesity
- Pregnancy
Where does cellulitis commonly occur?
Most commonly occurs on the leg.
What are the signs of cellulitis?
- Usually an obvious skin break where the infecting organism may have entered, such as a wound, macerated skin, fungal skin infection, an ulcer or a concomitant skin disorder (such as atopic eczema)
- Bullae (fluid-filled blisters) may also be present.
What are the symptoms of cellulitis?
- An acute onset of red, painful, hot, swollen, and tender skin, that spreads rapidly
- Fever, malaise, nausea, shivering and rigors- these may accompany or even precede skin changes
- Oedematous
What sign/ symptom would indicate infection with Staphylococcus aureus?
A golden-yellow crust can be present and indicate a staphylococcus aureus infection.
How can changes in cellulitis be monitoried?
There may be diffuse redness or a well-demarcated edge that can be marked with a pen in order to monitor progress.
What classification system is used to diagnose cellulitis?
Eron classification system.
Briefly describe 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 compromize.
Class IV- the person has sepsis or a severe life-threatening infection, such as necrotizing fasciitis.
What investigations should be ordered for cellulitis?
Investigations are not usually necessary but may be considered in certain cases and/or performed in secondary care settings, for example:
- A swab for culture
- Ultrasonography
- A skin biopsy
- White blood cell count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP)- to detect acute inflammation
When may a swab for culture be appropriate in diagnosing cellulitis?
If there is an open wound, penetrating injury, drainage, or an obvious portal for microbial entry, exposure to water borne-organisms, an infection acquired outside the UK or in severe cellulitis.
Briefly describe the treatment for class I cellulitis (no signs of systemic toxicity and no uncontrolled comorbidities)
Prescribe flucloxacillin 500–1000 mg four times daily for 5–7 days.
If this is unsuitable, or the person has a penicillin allergy prescribe doxycycline 200 mg on the first day then 100 mg once daily, for a total of 5–7 days.
When should IV antibiotics be considered in cellulitis?
Admit the patient for intravenous antibiotics if they are class 3 or 4. Also consider admission for frail, very young or immunocompromised patients.
