Cellulitis: a practical guide

Dr John Day Consultant in Infectious Diseases & General Medicine Southend University Hospital NHS Foundation Trust

77 yr old retired civil servant

 A&E presentation  c/o rigors  No significant past history  o/e pyrexial, lung creps

Investigations & Treatment

 Neuts 20.3 x 109/L  CRP 19 mg/L  CXR Normal

 Δ Pneumonia  Rx antibiotic  Discharged

Two days later

 Left lower leg   Red   Swollen   Painful

 Wife (retired casualty sister) Δ cellulitis   Investigations

  Neuts 20.3▼7.9   CRP 19▲100

OPAT: Out-Patient Antibiotic Treatment

 Ceftriaxone 2g od iv for 7 days  Reviewed

  Days 1, 3 & 7 Day Unit   Days 2, 4, 5 & 6 District Nurse

 CRP Days 1,3 & 7: 100▲136▼28  3 week review

  Erythema, desquamation, oedema   Bilateral VVs and chronic pedal oedema noted

Definition

 Cellulitis – an acute or sub-acute inflammation of subcutaneous tissue caused by bacterial infection

 Erysipelas – a type of cellulitis affecting dermal layer

Symptoms & Signs

 Flu-like symptoms: fever, rigors, chills  Delirium  Lethargy  Nausea & vomiting  Lower limb rash

  Rapidly-progressive   Erythematous areas   Painful when swollen

Precipitating Cause

 Leg ulcer  Penetrating injury  Blunt injury   Inter-digital intertrigo   Insect bites  None obvious

Predisposing Factors: Lymphoedema

 Chronic lymphoedema   Venous insufficiency   Obesity   Trauma   Surgery   Congenital   Previous Cellulitis

The Lymphoedema Support Network www.lymphoedema.org

Examination

  Inspect skin   Demarcation   Ulcers, Bullae   Features of chronic venous stasis or lymphoedema   Lymphangitis

  Palpate   Tenderness   Oedema, Fluctuance, Crepitus   Lymphadenopathy   Pedal pulses

Differential Diagnosis: Chronic Venous Disease

  Varicose eczema   Lipodermatosclerosis   Deep vein thrombosis   Thrombophlebitis

Differential Diagnosis: Other

  Oedema   Gout   Allergic reaction   Contact dermatitis   Erythema nodosum   Vasculitis

Differential Diagnosis: Complex Infections

 Diabetic feet  Pyomyositis  Septic arthritis  Osteomyelitis  Foreign bodies  Necrotizing fasciitis

Investigations

 WCC, CRP  Blood culture  Wound swab?  Doppler US?

Bacteria

  Isolated in only ¼ of hospital cases  Yield increased by skin biopsy testing  80% of isolated organisms are β-

haemolytic streptococci (Group A or G)  Staphylococcus aureus may contribute

to some cases

Antibiotic Treatment

 Cochrane Review 2010: “most recommendations made on single trials”

 Mild-Moderate   Flucloxacillin +/or Amoxicillin   Erythromycin or Clindamycin

 Severe   Benzylpenicillin + Flucloxacillin iv   Vancomycin or Clindamycin

Antibiotic Treatment

 OPAT   Ceftriaxone   Daptomycin

Considerations for IV treatment

 No studies of risk factors for complications  Septic shock  Rapid progression  Chronic oedema   Immunocompromised  Poorly-controlled diabetes  Other significant co-morbidities

Duration

 Duration of treatment   5-10 days

 The natural course of treated cellulitis:   Rapid defervesence   Skin gets worse before better   The post-cellulitic leg

CRP Day 0: 64 mg/l Day 1: 180 Day 2: 132 Day 5: 75 Day 7: 34

Day 2

Day 5

Day 7

Other Measures

 Analgesia  Anti-inflammatories?  Wound Care  Elevation  Emollients  Exercise  Elasticated compression

Cellulitis

Chronic oedema

Risk of recurrence

 Hospital cohort: 25 - 46% 1

 Population-based cohort: 11% 2  Associated with 1

  Chronic venous insufficiency   Lymphoedema   Obesity   Smoking   Tinea pedis   Local injury

1 Cox 1998; Jorup-Rönström 1987; Pavlotsky 2004. 2 Ellis Simonsen 2006

Prophylactic Antibiotics

 PATCH study 1

 Randomised control trial  ≥2 previous episodes of cellulitis  Penicillin 250mg bd  Recurrence rate 22 vs 37% (HR 0.55,

P=0.01)  However: effect less in patients with

lymphoedema 1 Thomas 2013

What came first…

…the systemic or the local infection?

Top Cellulitis Tips

 Often preceded by chills & rigors   If it’s not a UTI or an RTI, check the legs  Be sceptical about “chronic” and

“bilateral” cellulitis  Cellulitis and DVT rarely co-exist  Beware of treating wound swabs  Recognise the post-cellulitic leg and the

value of the CRP