Cellulitis and Erysipelas

Question 1

Define:

Answer 1

• Acute non-purulent spreading infection of the subcutaneous tissue, causing overlying skin inflammation
• Cellulitis and erysipelas are very similar -difference is that cellulitis affects deeper layers of the skin (subcutis)

Question 2

Aetiology:

Answer 2

•	Often results from: 
o	Penetrating injury
o	Local lesions (e.g. insect bites) 
o	Fissuring (e.g. anal fissures) 
•	These allow pathogenic bacteria to enter the skin

Question 3

Most common organisms:

Answer 3

o Streptococcus pyogenes – more commonly causes erysipelas
o Staphylococcus aureus – more commonly causes cellulitis
o NOTE: beware of MRSA
• Cellulitis of the orbit (orbital cellulitis) is usually caused by Haemophilus influenzae

Question 4

Risk factors:

Answer 4

o Skin break e.g. cut, open ulcer, surgery wound, insect bite, eczema
o Poor hygiene
o Poor vascularisation of tissue (e.g. due to diabetes mellitus)
o Immunocompromised – steroids, chemotherapy, HIV
o Obesity

Question 5

Epidemiology:

Answer 5

Very common

Question 6

Symptoms of cellulitis:

Answer 6

reddened skin is less clearly defined, often it is dark-red/purple. Can produce pus.

Question 7

Symptoms of Erysipelas:

Answer 7

painful, shiny light-red swelling of clearly defined area of skin. May also cause blisters and swelling of nearby lymph nodes. Fever and malaise.

Question 8

Symptoms of oribital and periorbital cellulitis:

Answer 8

• Periorbital Cellulitis - painful swollen red skin around the eye
• Orbital Cellulitis - painful or limited eye movements, visual impairment

Question 9

Signs:

Answer 9

•	Lesion
o	Erythema 
o	Oedema 
o	Warm tender indistinct margins 
o	Pyrexia - may suggest systemic spread 
•	NOTE: exclude the presence of an abscess (aspirate if pus suspected)
•	Periorbital
o	Swollen eye lids 
o	Conjunctival infection 
•	Orbital Cellulitis
o	Proptosis 
o	Impaired visual acuity and eye movements 
o	Test for RAPD, visual acuity and colour vision

Question 10

Investigations:

Answer 10

• Bloods - WCC, blood culture
• Discharge - sample and send for MC&S
• Aspiration (if pus is suspected)
• CT/MRI - if orbital cellulitis is suspected (helps assess posterior spread of infection)

Question 11

Management:

Answer 11

• Medical
o Oral penicillins (e.g. flucloxacillin) or tetracyclines are effective
o If hospital-acquired - treat empirically based on local guidelines and change depending on the sensitivity of cultured organisms
o Anti-inflammatory painkillers such as ibuprofen also help
• Surgical
o Orbital decompression may be needed in orbital cellulitis (EMERGENCY)
• Abscess
o Aspirate
o Incision and drainage
o Excised completely

Question 12

Complications:

Answer 12

• Sloughing of overlying skin
• Orbital cellulitis - may cause permanent loss of vision, spread to the brain, abscess formation, meningitis, cavernous sinus thrombosis

Question 13

Prognosis:

Answer 13

Good prognosis