Cellulitis and Erysipelas

Question 1

Cellulitis refers to an infection of the skin. Can this occur anywhere in the body?

Answer 1

• yes
• typically presents in the limbs though

Question 2

Cellulitis occurs when bacteria are able to penetrate the skin. In cellulitis, which layers of the skin are affected?

1 - epidermis (all cellular layers)
2 - dermis (hair follicles, nerve endings, glands, blood vessels and lymphatics)
3 - hypodermis (subcutaneous fat, connective tissue anchoring to basement membrane)
4 - all of the above

Answer 2

4 - all of the above

Question 3

Erysipelas is a form of bacterial skin infection. Which layers of the skin are affected?

1 - epidermis (all cellular layers)
2 - dermis (hair follicles, nerve endings, glands, blood vessels and lymphatics)
3 - hypodermis (subcutaneous fat, connective tissue anchoring to basement membrane)
4 - all of the above

Answer 3

1 - epidermis (all cellular layers)
2 - dermis (hair follicles, nerve endings, glands, blood vessels and lymphatics)

• typically does not affect deep tissue as much as cellulitis

Question 4

Cellulitis is a very common presentation in acute medicine. What is the incidence of cellulitis?

1 - 15 / 100,000
2 - 150 / 100,000
3 - 1500 / 100,000
4 - 15,000 / 100,000

Answer 4

4 - 15,000 / 100,000

Question 5

Cellulitis is a skin infection, typically caused by bacteria that affects all layers of the skin up to the deeper subcutaneous tissues. What age has a peak incidence of cellulitis?

1 - 20-30
2 - 30-50
3 - 40-60
4 - 50-60

Answer 5

4 - 50-60

Question 6

Cellulitis is a skin infection, typically caused by bacteria that affects all layers of the skin up to the deeper subcutaneous tissues. Are men or women more likely to develop cellulitis?

Answer 6

• affects both equally

Question 7

Cellulitis is a skin infection, typically caused by bacteria that affects all layers of the skin up to the deeper subcutaneous tissues. Infection is typically caused by a break in the skin. All of the following are common risk factors, EXCEPT which one?

1 - previous surgery
2 - immunosuppressed
3 - atopic dermatitis (eczema), Athlete’s foot,
4 - lymphoedema
5 - history of cellulitis
6 - obesity

Answer 7

1 - previous surgery
- may cause a wound infection, typically caused by S. aureus, but not cellulitis

• immunosuppression includes diabetes mellitus, HIV, immunosuppressive drugs

Question 8

Although the exact pathophysiology of cellulitis is poorly understood, exotoxins (proteins secreted by bacteria) have been linked. All of the following can cause cellulitis, but which 2 are most common?

1 - Streptococcus pyogenes
2 - Staphylococcus aureus
3 - Vibrio vulnificus
4 - Methicillin-resistant Staphylococcus aureus (MRSA)

Answer 8

1 - Streptococcus pyogenes
2 - Staphylococcus aureus

Pseudomonas may also occur

Question 9

When examining a patient with suspected cellulitis, are the borders of the infection typically well demarcated?

Answer 9

• no
• as the deeper dermis is affected, it can be difficult to identify the borders of infection

Question 10

Which of the following is NOT a common clinical sign of cellulitis?

1 - fever and malaise (feeling crappy)
2 - cool to touch
3 - redness with swelling
4 - tenderness to touch
5 - sign of broken skin where infection began

Answer 10

2 - cool to touch
- typically presents with warmth to the touch

Question 11

Does cellulitis typically present bilaterally?

Answer 11

• no
• presents unilaterally
• if bilateral, this suggestion other diagnosis

Question 12

Does cellulitis typically present gradually or acutely?

Answer 12

• presents acutely
• if it presents gradually, this suggests a different diagnosis

Question 13

When trying to identify if a patient has cellulitis, we can use history, examinations and investigations. Which of the following is NOT a typically differential for cellulitis?

1 - thrombophlebitis (inflammation causing blood clots to form in veins, mostly in the legs)
2 - DVT and PVD
3 - lymphoedema
4 - contact dermatitis (allergy)
5 - ingrown hair
6 - gout
7 - insect sting, cat scratch disease

Answer 13

5 - ingrown hair

Question 14

Diagnosis of cellulitis is typically a clinical diagnosis. However, all of the following can be useful, EXCEPT which one?

1 - LFTs
2 - U&Es (systemic inflammation may cause AKI)
3 - FBC (WBC may be raised)
4 - CRP and ESR
5 - swab to identify pathogen

Answer 14

1 - LFTs
- wouldn’t hurt, but typically does not aid with the diagnosis

• a swab and blood culture may be useful in some patients

Question 15

In a patient with confirmed cellulitis, we would typically wash, clean, moisturise and dress infected area regularly. In addition to this patients would be prescribed oral (IV in severe cases) antibiotics. Which of the following class would be the 1st line treatment in cellulitis in a patient with NKDA?

1 - Glycopeptides
2 - Penicillins
3 - Cephalosporins
4 - Macrolids

Answer 15

2 - Penicillins
- Flucloxacillin 1st line

• Cephalosporins are 1st line if patient has an allergy to penicillins

Question 16

When treating a patient, is it important to draw around the borders of cellulitis, if this is possible?

Answer 16

• yes
• helps identify the response to treatment

Question 17

The severity of cellulitis can be graded using the Eron classification, which is graded from I to IV with increasing severity. At what severity should patients be admitted to hospital?

1 - IV
2 - III
3 - II
4 - I

Answer 17

3 - II
- typically reviewed , but >II

Question 18

Despite treating cellulitis, complications may occur. One of these is bacteraemia. Which one of the following matches the description of bacteraemia?

1 - bacteria from cellulitis has entered the blood stream
2 - abnormal system wide response to an infection that is a medical emergency
3 - infection of the endocardium surrounding the heart
4 - bone marrow become infected

Answer 18

1 - bacteria from cellulitis has entered the blood stream

Question 19

Despite treating cellulitis, complications may occur. One of these is osteomyelitis. Which one of the following matches the description of osteomyelitis?

1 - bacteria from cellulitis has entered the blood stream
2 - abnormal system wide response to an infection that is a medical emergency
3 - infection of the endocardium surrounding the heart
4 - bone marrow becomes inflamed due to infection

Answer 19

4 - bone marrow becomes inflamed due to infection

Question 20

Despite treating cellulitis, complications may occur. One of these is sepsis. Which one of the following matches the description of sepsis?

1 - bacteria from cellulitis has entered the blood stream
2 - abnormal system wide response to an infection that is a medical emergency
3 - infection of the endocardium surrounding the heart
4 - bone marrow becomes inflamed due to infection

Answer 20

2 - abnormal system wide response to an infection that is a medical emergency

Question 21

Despite treating cellulitis, complications may occur. One of these is infective endocarditis. Which one of the following matches the description of infective endocarditis?

1 - bacteria from cellulitis has entered the blood stream
2 - abnormal system wide response to an infection that is a medical emergency
3 - infection of the endocardium surrounding the heart
4 - bone marrow becomes inflamed due to infection

Answer 21

3 - infection of the endocardium surrounding the heart

Question 22

Despite treating cellulitis, complications may occur. One of these is necrotising fasciitis. Which one of the following matches the description of necrotising fasciitis?

1 - bacteria from cellulitis has entered the blood stream
2 - abnormal system wide response to an infection that is a medical emergency
3 - infection of the endocardium surrounding the heart
4 - infection causes necrosis of deep dermis, including subcutaneous fat and muscle

Answer 22

4 - infection causes necrosis of deep dermis, including subcutaneous fat and muscle

Question 23

Necrotising fasciitis is a complication that can be caused by cellulitis where the deep subcutaneous skin layers including muscle and fat are necrosed. Is this dangerous?

Answer 23

• yes
• can develop rapidly, cause limb loss, sepsis and death
• typically affects the limbs

Question 24

Diabetic patients are at risk of recurrent cellulitis. Which of the following can be used to reduce the risk of recurrence?

1 - foot and leg checks
2 - correct footwear
3 - awareness of cellulitis
4 - all of the above

Answer 24

4 - all of the above

Question 25

When examining a patient with suspected Erysipelas, are the borders of the infection typically well demarcated?

Answer 25

• yes
• this is how to distinguish between cellulitis and Erysipelas

Question 26

When comparing cellulitis and erysipelas, which of them have can present with an unwell patient with fever, hot, painful erythematous and oedematous area primarily affecting face and extremities?

• cellulitis
• erysipelas,
• both

Answer 26

• both

Question 27

Although the exact pathophysiology of erysipelas is poorly understood, exotoxins (proteins secreted by bacteria) have been linked. All of the following can cause erysipelas, but which 1 is most common?

1 - Group A Streptococcus pyogenes
2 - Staphylococcus aureus
3 - Vibrio vulnificus
4 - Methicillin-resistant Staphylococcus aureus (MRSA)

Answer 27

1 - Group A Streptococcus pyogenes

Question 28

Typically which areas of the body do cellulitis and erysipelas affect?

1 - face and extremities
2 - torso and face
3 - back and legs
4 - face and scalp

Answer 28

1 - face and extremities

Question 29

A non-infectious cause for pyrexia should always be considered. Which blood test is most useful in distinguishing bacterial from non-bacterial causes of fever?

1 - CRP
2 - Differential WBC
3 - ESR
4 - Ferritin
5 - Procalcitonin

Answer 29

5 - Procalcitoni
- A serum biomarker that helps distinguish bacterial infections from other causes of infection or inflammation.

High in bacterial infection
Low in inflammation

Could be systemic juvenile idiopathic arthritis