Cellulitis and Erysipelas

Question 1

Definition of cellulitis and erysipelas (superficial form of cellulitis)?

Answer 1

Bacterial infection of the skin

Question 2

Commonest causative organisms of cellulitis/erysipelas?

Answer 2

Strep pyogenes

Staph aureus

Question 3

Presentation of cellulitis/erysipelas?

Answer 3

Acute onset

Inflammation (painful, hot, swollen, red)

Question 4

Risk factors for cellulitis/erysipelas?

Answer 4

Wounds, ulcers, bites
IV cannulae
Immunosuppression

Question 5

Cellulitis clinical features? (site, borders, systemic features/symptoms, sepsis potential)

Answer 5

Site - dermis, subcutaneous tissue

Borders - more patchy

Systemic - less common

Sepsis - more common

Question 6

Erysipelas clinical features? (site, borders, systemic features/symptoms, sepsis potential)

Answer 6

Site - epidermis

Borders - well demarcated

Systemic - fevers, rigors

Sepsis - less common

Question 7

Complications of cellulitis and which are medical emergencies?

Answer 7

Abscess
Sepsis (ME)
Necrotising fasciitis (ME)
Periorbital cellulitis (ME)
Orbital cellulitis (ME)

Question 8

Management of periorbital and orbital cellulitis?

Answer 8

Both medical emergencies

Periorbital - if visual impairment, give IV ABx

Orbital - if visual impairment, give IV ABx + consider surgery

Question 9

Investigations for cellulitis and erysipelas?

Answer 9

• Physical exam
• Basic obs (keeping an eye out for sepsis)
• Bloods
• Pus/wound swab for microscopy, culture, and sensitivities (MCS)
• CT/MRI (if orbital cellulitis to identify posterior spread of infection)

Question 10

Which bloods are appropriate in cellulitis/erysipelas and what would they show?

Answer 10

FBC - high WCC
CRP - elevated
Blood culture MCS - strep pyogenes positive (identifies pathogen + guides ABx choice)

Question 11

Management of cellulitis/erysipelas?

Answer 11

Conservative

• draw around lesion (to measure growth/shrinkage)
• monitor obs
• oral fluids

Medical

• oral ABx (e.g. flucloxacillin)
• IV ABx if severe

Admission necessary

• sepsis (high HR/RR, low BP)
• confusion/reduced consciousness (AVPU/GCS)