Cellulitis

Question 1

What is cellulitis?

Answer 1

An infection of the dermis and subcutaneous tissue

Typically caused by bacteria such as staphylococcus aureus, Group B streptococci, Group A streptococcus pyogenes, and MRSA.

Question 2

What are the causative agents for cellulitis?

Answer 2

*staphylococcus aureus
*Group B streptococci
*Group A streptococcus pyogenes
*MRSA

Question 3

List some associations with cellulitis.

Answer 3

• Immunosuppressed conditions like diabetes
• History of tinea pedis, a fungal infection between toe webs
• Trauma
• Pre-existing skin condition like dermatitis
• Lymphoedema
• Diabetes
• Obesity

These factors can increase the risk of developing cellulitis.

Question 4

Where does cellulitis typically occur?

Answer 4

commonly occurs on the shins and is usually unilateral - bilateral cellulitis is rare and suggests an alterative diagnosis

Question 5

What are common clinical presentations of cellulitis?

Answer 5

• well defined Erythema
• Swelling
• Blisters and bullae
• Systemic upset like Fever, Malaise and Nausea
  *evidence of Breach in skin barrier, linked to skin trauma, eczema, ulcers or fungal nail infection
• bullae formation

Cellulitis usually occurs on the shins and is often unilateral.

Question 6

What does a golden yellow crust with cellulitis indicate?

Answer 6

saphylococcus aureus infection

Question 7

What are the investigations for cellulitis?

Answer 7

• Swab culture
• X-ray for suspected osteomyelitis
• Ultrasound for suspected abscess

These investigations help confirm the diagnosis and assess complications.

Question 8

What is the management of cellulitis?

Answer 8

Mark the area of erythema to aid in detection of rapidly spreading cellulitis, and to monitor treatment response

Elevate if possible; Review if wound debridement is required

Antibiotic therapy

Question 9

What is the first-line antibiotic for cellulitis?

Answer 9

Flucloxacillin

It is effective against staphylococcus aureus and can be given orally or intravenously.

Question 10

What to give for antibiotic infection with penicillin sensitivity?

Answer 10

cephalosporin

Question 11

What to give for cellulitis infection with penicillin allergy

Answer 11

clindamycin macrolide antibiotic

Question 12

What is the classification for cellulitis?

Answer 12

Enron classification

Question 13

What is class I cellulitis?

Answer 13

no systemic toxicity or comorbidities

Question 14

What is class II cellulitis?

Answer 14

systemic unwell OR co-morbidity which can complicate or delay infection resolution

Question 15

What is class III cellulitis?

Answer 15

significant toxicity OR signficant co-morbidity

Question 16

What is class 4 cellulitis?

Answer 16

Sepsis or life threatening infection like necrotising fasciitis

Question 17

What does systemic toxicity indicate?

Answer 17

Systemic toxicity includes acute confusion, tachycardia, tachypnoea, hypotension.

Question 18

True or false: Class I cellulitis requires admission to the hospital.

Answer 18

FALSE

Class I cellulitis can often be treated with oral antibiotics without admission.

Question 19

What co-morbid iss complicate cellulitis resolution?

Answer 19

Co-morbidities that complicate infection resolution includes peripheral arterial disease, chronic venous insufficiency, or morbid obesity.

Question 20

What are the Eron classes for assessing severity of cellulitis?

Answer 20

• Class 1: No systemic toxicity or comorbidities
• Class 2: Systemic unwell OR co-morbidity
• Class 3: Significant toxicity OR significant co-morbidity
• Class 4: Sepsis or life-threatening infection

These classifications help determine the appropriate management and treatment.

Question 21

What are indications for admission in cellulitis cases?

Answer 21

• Class III - Class IV cellulitis
• Rapidly deteriorating cellulitis
• Under 1 year of age or frail
• Immunosuppression
• Significant lymphoedema
• Facial cellulitis

Admission is necessary for severe cases or specific risk factors.

Question 22

Which class cellulitis should hospital admission be considered individually?

Answer 22

class II

Question 23

What are some differentials for cellulitis?

Answer 23

• Deep vein thrombosis
• Allergic reactions or contact dermatitis
• Superficial thrombophlebitis
• Necrotizing fasciitis
• Erysipelas

Differentiating these conditions is crucial for appropriate management.

Question 24

What is erysipelas?

Answer 24

an infection of the supericial dermal layer. It will have markedly raised reddened skin with distinct borders and has lymphatic involvement.

Question 25

What is the cause of erysipelas?

Answer 25

Group A streptococcus pyogenes Is the most common causative agent.

Question 26

What is the presentation of erysipelas?

Answer 26

*Swelling inflamed butterfly appearance of rash *Fever *Chills *Rigours *Warmth *Lymphoedema

Question 27

What distinguishes **orbital cellulitis** from **peri-orbital cellulitis**?

Answer 27

Orbital cellulitis involves optic nerve dysfunction. Peri-orbital cellulitis is the infection of the soft tissue around the eye ## Footnote Peri-orbital cellulitis does not involve the orbit itself.

Question 28

What are **red flag symptoms** for orbital cellulitis?

Answer 28

* Limited or painful eye movements * Vision changes * Proptosis * Focal neurologic signs ## Footnote These symptoms indicate a more serious condition requiring urgent attention.

Question 29

What are the **common causative organisms** for orbital cellulitis?

Answer 29

* Haemophilus influenzae type B * Streptococcus pneumoniae * Staphylococcus aureus ## Footnote These organisms often spread from upper respiratory tract infections.

Question 30

What are the investigations for cellulitis?

Answer 30

Bacterial swab from eye, throat, nose Bloods: FBC, blood cultures Contrast CT orbits, sinuses +/- brain to look for spread/complications

Question 31

What investigation is contraindicated for orbital cellulitis?

Answer 31

An LP is contra-indicated due to the risk of raised ICP associated with intracranial spread

Question 32

What is the management for **severe peri-orbital or orbital cellulitis**?

Answer 32

* Refer to an ophthalmologist urgently * Administer antibiotics according to local guidelines ## Footnote IV antibiotics are typically required for orbital cellulitis.

Question 33

What complications can arise from **peri-orbital cellulitis**?

Answer 33

* Orbital cellulitis * Lagophthalmos * Lid necrosis ## Footnote These complications can lead to more severe conditions.

Question 34

What complications can arise from **orbital cellulitis**?

Answer 34

* Permanent vision loss * Intracranial spread * Cavernous sinus thrombosis * Fulminant sepsis * Exposure keratopathy * Optic neuropathy ## Footnote Orbital cellulitis is a serious condition that can lead to significant morbidity.

Question 35

How to differentiate cellulitis from erysipelas?

Answer 35

Erysipelas= raised border, well-demarcated Cellulitis = flat border, poorly-demarcated

Question 36

What is the cause of purulent cellulitis?

Answer 36

Staphylococcus aureus or Streptococcus pyogenes

Question 37

What is the cause of non purulent cellulitis?

Answer 37

Streptococcus pyogenes

Question 38

What may investigation reveal with cellulitis?

Answer 38

High WCC, AKI on U&Es

Question 39

What is the medical management of erysipelas?

Answer 39

Flucloxacillin

Question 40

What microbrisl agent is involved in bite wounds?

Answer 40

Mixed flora like Pasteurella species

Question 41

How to manage moderate severity insect bite wounds?

Answer 41

Oral co-amoxiclav for broad spectrum coverage against Staphylococcus aureus, Streptococcus pyogenes, and Pasteurella species