Cellulitis Darren Wilson Antibiotic Pharmacist Royal Bournemouth Hospital

Some Facts Definition – “a diffuse spreading inflammation of the subcutaneous tissue caused by bacterial infection” Definition – “a diffuse spreading inflammation of the subcutaneous tissue caused by bacterial infection” True incidence not really known True incidence not really known –Not reportable so no definitive data –SSTI’s account for around 176 admissions per 100,000 of the UK population –Accounted for ~3% of emergency medical consultations in one UK hospital –A 2006 study in the USA found an incidence of 24.6 cases per 1000 person years

Risk Factors Bites / Stings Bites / Stings Skin breaks E.g. fissures, cuts, puncture wounds, lacerations Skin breaks E.g. fissures, cuts, puncture wounds, lacerations Other infections E.g.Athletes foot Other infections E.g.Athletes foot Diabetes Diabetes PVD PVD Ischaemic ulcers Ischaemic ulcers Obesity Obesity Lymphoedema Lymphoedema

Clinical Signs and Symptoms Tenderness and heat Tenderness and heat Pain Pain Erythema Erythema Swelling Swelling

Clinical Signs and Symptoms Tenderness and heat Tenderness and heat Pain Pain Erythema Erythema Swelling Swelling Malaise Malaise Fever / Chills Fever / Chills Poorly demarcated borders Poorly demarcated borders Local abcesses Local abcesses

Complications Abcess formation Abcess formation Septicaemia Septicaemia Lymphoedema Lymphoedema Necrotizing skin infections Necrotizing skin infections

Causes Microbiological diagnosis is rare Microbiological diagnosis is rare Primarily Gram +ve organisms Primarily Gram +ve organisms –Group A Streptococcus (also groups B,C and G) –Staphylococcus aureus Less commonly: Less commonly: –Gram –ve’s such as E.coli, Pseudomonas –Anaerobes - esp secondary to wounds, ulcers, diabetic foot Some rare other causes Some rare other causes

Treatment Prompt Antibiotics Prompt Antibiotics –Severe cases need hospital admission for IV therapy –Non-severe cases can be managed at home with oral antibiotics Bed rest and elevation of the affected part Bed rest and elevation of the affected part Analgesia Analgesia Good skin care Good skin care

Which patients should be admitted to hospital? Signs of septicaemia (hypotension, tachycardia, severe pyrexia, confusion, tachypnoea or vomiting) Signs of septicaemia (hypotension, tachycardia, severe pyrexia, confusion, tachypnoea or vomiting) Continuing or deteriorating systemic signs after 48 hours of treatment Continuing or deteriorating systemic signs after 48 hours of treatment Unresolving or deteriorating local signs despite trials of first and second line antibiotics Unresolving or deteriorating local signs despite trials of first and second line antibiotics

Antibiotic Therapy MUST choose a drug which covers Group A Streptococcus and Staph aureus* MUST choose a drug which covers Group A Streptococcus and Staph aureus* Flucloxacillin is the first line choice (good activity against both organisms) Flucloxacillin is the first line choice (good activity against both organisms) Amoxicillin is highly active against Group A Strep but not against Staph. aureus Amoxicillin is highly active against Group A Strep but not against Staph. aureus Several alternatives in penicillin allergy including Macrolides (erythromycin, clarithromycin), Clindamycin, Cephalosporins (Cefuroxime) and some others Several alternatives in penicillin allergy including Macrolides (erythromycin, clarithromycin), Clindamycin, Cephalosporins (Cefuroxime) and some others *Group A Strep is the most common in Lymphoedema

Antibiotic Therapy (2) Very occasionally use two agents in combination most usually Benzylpenicillin + Flucloxacillin Very occasionally use two agents in combination most usually Benzylpenicillin + Flucloxacillin In severe case may add another agent such as Gentamicin to give good gram –ve cover In severe case may add another agent such as Gentamicin to give good gram –ve cover If MRSA is suspected will need an anti- MRSA agent such as Vancomycin or Teicoplanin If MRSA is suspected will need an anti- MRSA agent such as Vancomycin or Teicoplanin

Outcomes Cellulitis usually responds fully to appropriate antibiotics Cellulitis usually responds fully to appropriate antibiotics IV Abx can be switched to PO once a good response occurs IV Abx can be switched to PO once a good response occurs Total course lengths of 7-14 days are usually required Total course lengths of 7-14 days are usually required In lymphoedema longer courses may be necessary – the BLS recommend a minimum of 14 days from the time a definite clinical response is observed In lymphoedema longer courses may be necessary – the BLS recommend a minimum of 14 days from the time a definite clinical response is observed

Other Considerations Cellulitis is often recurrent especially in lymphoedema Cellulitis is often recurrent especially in lymphoedema “in case” antibiotics are recommended for any patient who has had a previous attack “in case” antibiotics are recommended for any patient who has had a previous attack –2 weeks of amoxicillin, flucloxacillin or clindamycin Prophylactic antibiotics - the jury is undecided! Prophylactic antibiotics - the jury is undecided! –BLS suggest this should be offered to patients who have two or more attacks per year –Penicillin or erythromycin is appropriate –Initially for 1 – 2 years (lifelong if further episode) –Limited evidence only – a 2014 meta analysis of 5 trials (535 pts) concluded that prophylaxis is effective but much more research is needed