Cellulitis

Question 1

Define cellulitis

Answer 1

Cellulitis is a bacterial infection of the dermis (skin) and subcutaneous tissue (soft tissues)

Question 2

Which layers does cellulitis affect

Answer 2

Skin (dermis)

Subcutaneous tissue (soft tissue)

Question 3

Name the two most common causative organsims of cellulitis

Answer 3

Streptococcus pyogenes

Staphylococcus aureus

Question 4

A disruption in the skin barrier provides a point of entry for the bacteria in cellulitis.

Name potential causes that can result in a breach of the skin barrier

Answer 4

Skin trauma

Eczematous skin

Fungal nail infections

Ulcers

Question 5

What part of the body does cellulitis affect

Answer 5

May occur anywhere on the body

Most commonly affects the lower limbs

Question 6

Name some of the risk factors associated with cellulitis

Answer 6

Age: mostly seen in middle-aged to older adults

Immunocompromised e.g. diabetes

Predisposing skin condition that affect the integrity of the skin barrier or impair venous/lymph drainage e.g. ulcers, pressure sores, trauma, lymphoedema

Question 7

What are the hallmark features of cellulitis

Answer 7

Features of inflammation e.g. pain, swelling, warth (hot to touch) and erythema (red)

Question 8

Name some of the skin changes that are associated with cellulitis

Answer 8

Tense

Thickened

Oedematous

Bullae present (fluid filled blisters)

Question 9

How is cellulitis diagnosed

Answer 9

Cellulitis is a clinical diagnosis based on the classic appearance of erythematous, warm and oedematous skin.

Question 10

What is the name of the classifcation tool used to assess the severity of cellulitis

Answer 10

Eron classification

Question 11

What investigations can aid in cellulitis

Answer 11

• Mark the area of erythema to aid in detection of rapidly spreading cellulitis
• Lab investigations are often unnecessary if the patient is otherwise clinically well
• If presenting to secondary care, bloods and blood cultures may be requested
  
  • <10% of blood cultures are positive in cellulitis

Question 12

What is the first line therapy for mild/moderate cellulitis

Answer 12

oral or IV flucloxacillin

Question 13

What is the first line therapy for mild/moderate cellulitis if the patient is pregnant

Answer 13

Clarithromycin/erythromycin

Question 14

What is the first line therapy for mild/moderate cellulitis if the patient has a penicillin allergy

Answer 14

Doxycycline

Question 15

What is the first line therapy options for severe cellulitis

Answer 15

co-amoxiclav, cefuroxime, clindamycin, or ceftriaxone

Question 16

Name some of the complications of cellulitis

Answer 16

Necrotising infections e.g. necrotising fasciitis

Sepsis

Abscess – may require incision and drainage

Myositis (infection of muscle)

Recurrent cellulitis

Lymphoedema – due to irreversible damage to lymphatic system