cellulitis

Question 1

definition of cellulitis

Answer 1

acute non-purulent spreading infection of the subcut tissue, causing overlying skin inflammation

Question 2

aetiology of cellulitis

Answer 2

from penetrating injury (eg IV cannulation, local lesions (insect bites, subcut cysts, surgery) or fissuring (anal fissures, toe webspaces)

allow pathogenic bacteria to enter the skin

in rare cases of septicaemia - can arise spontaneously from blood-borne sources

Question 3

most common organisms causing cellulitis

Answer 3

staphy pyogenes and staph aureus

MRSA

if in orbit - Haemophilus influenzae is the most common cause - often arises from adjacent sinuses

Question 4

epidemiology of sinusitis

Answer 4

very common

Question 5

RF for cellulitis

Answer 5

skin break

poor hygiene

poor vascularisation of tissue = dm

venous insufficiency - fragile skin and reduced local host defence

eczema

oedema and lymphoedema

obesity

previous episodes of cellulitis

toe web abnormalities

Question 6

sx of cellulitis

Answer 6

may be history of a cut, scratch or injury

red

swollen

heat

tenderness

periorbital - painful, swollen red skin around eye

orbital cellulitis - painful or limited eye movements, visual impairment

Question 7

signs of cellulitis

Answer 7

lesion - erythema, oedema, warm tender, indistinct margins. Pyrexia may signify systemic spread

exclude abscess - test for fluid thrill or flucturation. Aspirate if pus suspected

periorbital - swollen eyelid, conjunctival injection

orbital cellulitis - proptosis, imparied acuity and eye movement. Test for relative afferent pupillary defect, visual acuity, and colour vision (to monitor optic nerve function)

Question 8

Ix for cellulitis

Answer 8

blood - WCC (high or low) and culture and sensitivity, ESR (high), CRP (high), UE

discharge - culture and sensitivity

aspiration - often non-purulent, not necessary

CT/MRO - when orbital cellulitis is suspected - to assess posterior spread of infection

Question 9

medical management of cellulitis

Answer 9

oral penicillin - flucloxacillin, benylpenicillin, coamxiclav or tetracyclins for community aquired

in hospital - empirically using local microbiological guidelines - change depending on sensitivity of any cultured organisms

IV AB may be necessary

Question 10

surgical treatment of cellulitis

Answer 10

orbital decompression may be necessary in orbital cellulitis

this is an emergency

Question 11

Mx of abscess

Answer 11

can be aspirated, incised or drained or excised completely

Question 12

complications of cellulitis

Answer 12

sloughing of overlying skin

localised tissue damage

in orbital - permenant vision loss, spread to brain, abscess formation, meningitis, cavernous sinus thrombosis

Question 13

prognosis of cellulitis

Answer 13

good with treatment

Question 14

definition of erysipelas

Answer 14

distinct from superficial cellulitis with notable lymphatic involvement

raised and sharply demarcated from uninvolved skin