Cellulitis


44. A 23 year old man presents with acute cellulitis around the right knee with lymphangitis along the medial thigh and tender right inguinal lymphadenopathy. His temperature is 38.3°. He sustained a wound over the right knee 10 days ago. The wound appeared to heal fairly well initially but redness and tenderness commenced two days ago. How will you manage him?

 

This young man presents with features of wound infection complicated by acute cellulitis, lymphangitis & lymphadenitis

 

Given the location over an underlying joint, this is a high-risk infection

 

I would manage this problem by performing a thorough clinical assessment & some investigations with a view to:

 

Followed by the appropriate treatment & arrangement of F/U

 

In further detail, I would

 

1)    Further focused history- to confirm dx & exclude complications

a.     Cause of wound- guide to likely organism & Rx

                                               i.     Laceration/ cut/ penetrating injury

                                             ii.     Dirty/ soiled wound

                                            iii.     Animal or human bite

                                            iv.     Water-related injury

1.     Fisherman

2.     Swimmers

3.     Aquarium owners

b.     Consequences

                                               i.     Cellulitis

1.     Spreading, tender erythema

2.     + Fever & systemic toxicity

3.     +/- Lymphangitis/ lymphadenitis

4.     +/- Blistering

                                             ii.     Lymphangitis

                                            iii.     Lymphadenitis

                                            iv.     Septic arthritis

                                             v.     Osteomyelitis

                                            vi.     Necrotising fasciitis

1.     Severe systemic toxicity

                                          vii.     Septicaemia

c.     Past Hx

                                               i.     Immunosuppression

1.     Atypical organisms

2.     Lower threshold for IV treatment

                                             ii.     Prostheses

1.     Joint

2.     Vascular

d.     Medications

                                               i.     Previous antibiotic treatment- resistance

                                             ii.     Interactions

                                            iii.     Tetanus vaccination status

e.     Allergies

                                               i.     Penicillin

f.      Social history

                                               i.     Ensure compliance with Ax treatment & F/U

2)    Examination

a.     General

                                               i.     Vital signs

                                             ii.     Hydration status

b.     Wound (portal of entry)

                                               i.     Open or closed

                                             ii.     Inflammation

                                            iii.     Abscess formation- fluctuance

c.     Complications

                                               i.     Surrounding tissue- cellulitis

                                             ii.     Inguinal LNs- tender lymphadenopathy

                                            iii.     Knee Jt

1.     Red flags for septic arthritis

a.     Swelling

b.     Erythema

c.     Marked reduction in ROM

d.     Systemic features of inflammation

3)    Investigations

a.     Bloods

                                               i.     FBC/ ESR/ CRP

                                             ii.     Blood cultures?

1.     Low diagnostic yield < 5%

b.     Imaging

                                               i.     Knee X-ray- AP/ Lat/ oblique

c.     Microbiology

                                               i.     Wound swab

                                             ii.     Joint aspirate +/- knee US

4)    Admit to hospital for IV Axs (or HITH program)

a.     Complicated cellulitis over large joint

b.     Significant systemic features

5)    Treatment

a.     Non-pharmacological

                                               i.     Rest

                                             ii.     Elevation of limb

                                            iii.     Delineate margins with a textor

                                            iv.     Non-adhesive dressings

b.     Pharmacological

                                               i.     Analgesia

                                             ii.     IV Antibiotics

1.     Flu/dicloxacillin 2g IV qid

OR if penicillin hypersensitivity

2.     Cephazolin or Cephalothin IV

OR if immed pen hypersensitivity

3.     Clindamycin IV or Lincomycin IV

OR

4.     HITH IV therapy

a.     Cephazolin 2g IV daily + probenacid PO 1g daily

b.     Cephazolin 2g IV bd

                                            iii.     Treatment of underlying cause

1.     Tinea pedis

2.     Dermatitis

                                            iv.     DVT prophylaxis- if immobilised for a while

1.     Compression stockings

2.     +/- UF heparin SC 5000 u bd

c.     Surgical

                                               i.     Joint lavage/ wash-out

6)    Ongoing management

a.     Supportive therapy

b.     Change to oral Axs

                                               i.     Afebrile

                                             ii.     + Substantial improvement in erythematous rash

1.     From 3 days- 2 wks!

                                            iii.     Continue oral Axs for further 10 days

7)    Follow-up

 

Cellulitis

Mild early cellulitis or erysipelas

Severe cellulitis

Severe systemic symptoms

Unresponsive to PO Rx after 48 hrs

OR

 

Erysipelas

 

Necrotising fasciitis

PLUS

PLUS

+/-

 

 

 

DD – gout, septic arthritis, osteomyelitis

 

NB – the lymphangitis, acute onset, tender lymphadenopathy all indicate Strep pyogenes as the cause. Spreads by hyaluronidase + streptokinase enzymes

Other micro – S Aureus (remember MRSA if he has been hospitalised) – high risk as post injury

 

History

 

Examination

 

Investigations

 

Management