DVT & Cellulitis Flashcards

1
Q

What is cellulitis?

A

A bacterial infection that affects the dermis and deeper subcutaneous tissue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What causes cellulitis?

A

A break in the skin barrier that allows entry for bacteria:

  • Skin trauma
  • Skin conditions e.g. eczema, chronic venous ulcers, psoriasis
  • Venous insufficiency and peripheral vascular disease
  • Obesity
  • Skin breaks (such as recent cuts or insect bites)
  • Lymphoedema
  • Previous cellulitis
  • Surgery to the lower limb including saphenectomy
  • Tinea pedis
  • T2DM
  • IVDU
  • Alcoholism
  • Immunosuppression
  • Pregnancy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 3 most common organisms causing cellulitis?

A

1) Staph. aureus

2) Group A Strep. (mainly streptococcus pyogenes)

3) Group C Strep. (mainly streptococcus dysgalactiae)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What should be considered as the causative organism of cellulitis in patients with repeated hospital admissions and antibiotics?

A

MRSA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Clinical features of cellulitis?

A

Unilateral:

  • swelling
  • erythema
  • warmth
  • tenderness
  • bullae (fluid-filled blisters)
  • systemic upset e.g. fever, malaise, nausea (SEPSIS red flag)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where does cellulitis usually occur?

A

On the shins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

A golden-yellow crust in cellulitis indicates which causative organism?

A

Staph. aureus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Is cellulitis a rapid or slow onset?

A

Rapid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

A rapidly progressive and blistering rash should prompt consideration of what?

A

Necrotising fasciitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What classification system is used to guide management of cellulitis?

A

Eron classification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the Eron classification

A

Class I - no systemic toxicity or comorbidity

Class II - systemic toxicity or comorbidity

Class III - significant systemic toxicity or significant comorbidity

Class IV - sepsis or life-threatening infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What Eron classification indicates admission for IV Abx?

A

Class III and IV

N.B. Admission is also considered for frail, very young or immunocompromised patients and those with facial, periorbital or orbital cellulitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Give some indications for admission for IV Abx in cellulitis

A

1) Has Eron Class III or Class IV cellulitis.

2) Has severe or rapidly deteriorating cellulitis (for example extensive areas of skin).

3) Is very young (under 1 year of age) or frail.

4) Is immunocompromised.

5) Has significant lymphoedema.

6) Has facial cellulitis (unless very mild) or periorbital cellulitis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Investigations in cellulitis?

A

Consider sepsis 6.

1) FBC:
- leucocytosis or neutrophilia
- N.B. only half of patients presenting with cellulitis have a raised WCC

2) U&Es
- assess for AKI

3) CRP or ESR

4) Consider blood cultures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Differentials for cellulitis?

A

1) DVT

2) Varicose or venous stasis eczema

3) Superficial thrombophlebitis

4) Necrotising fasciitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is typical 1st line Abx for mild/moderate cellulitis?

A

Oral flucloxacillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

1st line Abx for mild/mod cellulitis in pregnancy?

A

Oral erythromycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

1st line Abx for mild/mod cellulitis in penicillin allergy?

A

oral clarithromycin, erythromycin or doxycycline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What can you do to assess whether cellulitis is spreading?

A

mark the area of erythema to detect spreading cellulitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is usually the 1st choice Abx for cellulitis near the eyes or nose?

A

Co-amoxiclav

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

1st line Abx in severe cellulitis?

A

Oral/IV co-amoxiclav, oral/IV clindamycin, IV cefuroxime or IV ceftriaxone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Complications of cellulitis?

A
  • systemic infection
  • subcutaneous abscess formation
  • myositis
  • fasciitis
  • death
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is orbital cellulitis?

A

Orbital cellulitis is an infection around the eyeball involving the fat and muscles behind the orbital septum.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is orbital cellulitis usually caused by?

A

A spreading URT infection from the sinuses.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Is orbital celluliti dangerous?

A

Yes - carries a high mortality rate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Risk factors for orbital cellulitis?

A
  • Childhood
  • Previous sinus infection
  • Lack of Haemophilus influenzae type b (Hib) vaccination
  • Recent eyelid infection/ insect bite on eyelid (Peri-orbital cellulitis)
  • Ear or facial infection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Clinical features of orbital cellulitis?

A

1) Pain
- throbbing or deep ache
- worse on eye movement

2) Proptosis (exophthalmos)

3) Periocular swelling (oedema)

4) Pupillary involvement and visual changes

5) Palsy (ophthalmoplegia)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is proptosis (exophthalmos)?

A

Forward displacement or protrusion of the eyeball due to inflammation and oedema of the orbital contents, or in severe cases, formation of an abscess.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How can periocular swelling in orbital cellulitis present?

A
  • swollen eyelids
  • chemosis (swelling of conjunctiva)
  • erythema
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What visual changes may be seen in orbital cellulitis?

A
  • blurred vision
  • decreased visual acuity
  • diplopia
  • loss of vision (severe cases)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What pupillary defect may be seen in orbital cellulitis?

A

A relative afferent pupillary defect (RAPD) may be present, indicating optic nerve involvement.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What causes palsy (ophthalmoplegia) in orbital cellulitis?

A

Due to the inflammation and swelling in the orbit, there can be restriction or paralysis of the extraocular muscles, leading to impaired eye movements (ophthalmoplegia).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Management of orbital cellulitis?

A

Orbital cellulitis requires emergency admission under ophthalmology and IV antibiotics. Surgical drainage may be needed if an abscess forms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the main differential for orbital cellulitis?

A

Periorbital cellulitis (less serious)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is periorbital cellulitis?

A

Periorbital cellulitis (also known as preseptal cellulitis) is an eyelid and skin infection in front of the orbital septum (in FRONT of the eye).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How does periorbital cellulitis present?

A

It presents with swollen, red, hot skin around the eyelid and eye.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Management of periorbital cellulitis?

A

1) Exclude orbital cellulitis

2) Systemic antibiotics (oral or IV).

reorbital cellulitis can develop into orbital cellulitis, so vulnerable patients (e.g., children) or severe cases may require admission for monitoring.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is necrotising fasciitis (NF)?

A

A severe and rapidly progressive soft tissue infection that causes necrosis of the subcutaneous tissues and fascia, sometimes also affecting the muscle.

It needs rapid management and it has a high mortality rate of around 32%.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are the main risk factors for developing necrotising fasciitis?

A

1) diabetes mellitus

2) CKD

3) alcohol excess

4) advanced age or frailty

5) malnutrition

6) metastatic cancer

7) immunocompromised (e.g. AIDS or recent chemotherapy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Cause of NF?

A

The large majority of cases of NF are related to some form of trauma, either an external injury or a surgical wound.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

How can NF be categorised?

A

Depending on the causative organism.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What are the 4 types of NF?

A

Type I: polymicrobial

Type II: monomicrobial (caused by Streptococcus pyogenes)

Type III: monomicrobial (caused by the Clostridium species most commonly)

Type IV: fungal NF, mainly Candida species

43
Q

What is the most common type of NF?

A

Type I (70-90%)

44
Q

Where is type I NF typically found?

A

On the drunk or perineum

45
Q

Which organism causes type II NF?

A

Streptococcus pyogenes

46
Q

Who does Type II NF typically occur in?

A

Younger patients, healthy individuals with a history of trauma

47
Q

Where is type II NF typically found?

A

Limbs

48
Q

What organism causes type III NF?

A

Clostridium species

49
Q

Who is type III NF typically found in?

A

IVDU

50
Q

What organism is type IV NF caused by?

A

Mainly Candida

51
Q

Who is type IV NF typically seen in?

A

Mainly found in immunocompromised patients, and is particularly aggressive and extensive.

52
Q

Pathophysiology of NF?

A

1) Bacteria produce enzymes that result in necrosis of the fascia and fat

2) Bacteria also cause thrombosis in the vessels leading to ischaemia which further promotes necrosis

N.B. This ischaemia originally produces intense pain for the patient but, as the disease progresses, can result in hypoesthesia/anaesthesia.

53
Q

What is gas gangrene?

A

A form of NF caused by clostridium specicies (C. perfringens), resulting in gas being produced by the bacteria within the tissue.

54
Q

What bacteria causes gas gangrene?

A

C. perfringens

55
Q

How do the Clostridium species cause gas gangrene?

A

The organisms produce alpha and beta toxins that lead to extensive tissue damage, alongside producing large volumes of gas within the tissue.

56
Q

Presentation of gas gangrene?

A
  • same as NF
  • tissue crepitus is often present on light palpation of affected area
57
Q

Clinical features of NF?

A
  • Swelling (80%)
  • Pain (79%) - patients will complain of severe pain, often out of keeping with the overt clinical signs.
  • Erythema (70%)
  • Induration

There may be history of skin breach.

There will be rapid progression to skin crepitus, vesicles / bullae, and obvious skin necrosis.

58
Q

Investigations in NF?

A

1) FBC:
- raised WCC

2) CRP: raised

3) U&Es:
- signs of worsening renal function
- hypnatraemia

4) lactate: raised

5) ABG: metabolic acidosis

59
Q

Management of NF?

A

1) Surgical emergency - needs immediate resuscitation and debridement.

2) Urgent broad spectrum Abx

3) Resuscitation IV fluids (and catheterise patient)

4) Mark and time denote any area of redness or discolouration

60
Q

What is the only definitive management of NF?

A

Surgical debridement

61
Q

What is a DVT?

A

The formation of a thrombus (blood clot) in a deep vein, which partially or completely obstructs blood flow.

62
Q

Give some risk factors for a DVT

A

1) male

2) increasing age

3) immobilisation e.g. hospitalisation, long haul flight

4) inflammatory state e.g. vasculitis, sepsis

5) malignancy

6) medication e.g. chemo, HRT, COCP

7) obesity

8) pregnancy

9) thombophilia

10) smoking

11) varicose veins

63
Q

Why is pregnancy a prothrombotic state?

A

As there is venous stasis from the gravid uterus obstructing venous return, cardiovascular changes associated with pregnancy affect the endothelium and changes in the clotting cascade favour hypercoagulability.

64
Q

What is a thrombophilia?

A

Thrombophilias are conditions that predispose patients to develop blood clots.

65
Q

Give some examples of thrombophilias?

A

1) antiphospholipid syndrome

2) Factor V Leiden

3) antithrombin deficiency

4) protein C or S deficiency

5) hyperhomocysteinaemia

6) prothrombin gene variant

7) activated protein C resistance

66
Q

What condition is antiphospholipid syndrome often associated with?

A

Recurrent miscarriage

67
Q

What is Virchow’s triad?

A

Virchow’s triad encompasses the 3 changes that contribute to the formation of venous thromboses:

1) hypercoagulability of blood e..g factor V Leiden, malignancy, COCP

2) stasis of blood e.g. immobilisation

3) changes to endothelium e.g. smoking, HTN

68
Q

Clinical features of a DVT?

A
  • unilateral leg pain and swelling
  • commonly found in lower leg
  • pain exacerbated by exertion
  • swelling usually confined to calves; may be pitting oedema
  • skin changes e.g. dilated superficial veins
69
Q

What may examination of the affected leg in DVT reveal?

A
  • increased temp
  • tender calf that is more solid in consistency
  • tenderness on palpation
  • difference in size of calves
70
Q

How can leg swelling be investigated in a DVT?

A

Measure the circumference of the calf 10cm below the tibial tuberosity.

71
Q

What size difference between calves in significant?

A

More than 3cm difference between calves is significant.

72
Q

What is the key complication of a DVT?

A

PE (co-exists in 40-50% of patients).

73
Q

If a patient is suspected of having a DVT, what is next step?

A

Wells score

74
Q

What Wells score indicates that a DVT is likely?

A

2 or more

75
Q

If the Wells score indicates that a DVT is likely (i.e. 2 points or more), what is next step?

A

Proximal leg US should be carried out within 4 hours.

76
Q

How quickly should a leg US be done in a suspected DVT if the Wells score is 2 or more?

A

within 4 hours

77
Q

If the proximal leg US is positive for a DVT, what is next step?

A

Anticoagulation

78
Q

If the proximal leg US is negative for a DVT, what is next step?

A

D-dimer test.

A negative scan and negative D-dimer makes the diagnosis unlikely and alternative diagnoses should be considered.

79
Q

After a positive Wells score (≥2), if if a proximal leg vein US scan cannot be carried out within 4 hours, what should you do?

A

Perform a d-dimer test and interim therapeutic anticoagulation administered whilst waiting for the proximal leg vein US scan (which should be performed within 24 hours)

80
Q

What interim therapeutic anticoagulation is given in a suspected DVT whilst waiting for an US (if waiting time is >4 hours)?

A

DOAC e.g. apixaban

81
Q

If the US is negative but the d-dimer is positive in a DVT, what is next step?

A

1) stop interim therapeutic anticoagulation

2) offer a repeat proximal leg vein ultrasound scan 6 to 8 days later

82
Q

If the Wells score indicates that a DVT is unlikely (i.e. ≤1 point), what is next step?

A

Perform a d-dimer test (within 4 hours).

83
Q

If the Wells score was ≤1 and the d-dimer is negative, what is next step?

A

if the result is negative then DVT is unlikely and alternative diagnoses should be considered

84
Q

If the Wells score was ≤1 and the d-dimer is positive, what is next step?

A

proximal leg US scan within 4 hours

85
Q

What is the cornerstone of VTE management?

A

anticoagulant therapy

86
Q

1st line anticoagulant in confirmed DVT?

A

DOAC e.g. apixaban or rivaroxaban

87
Q

1st line anticoagulant in suspected DVT whilst waiting for confirmation?

A

DOACs

88
Q

1st line DOACs in DVT?

A

apixaban or rivaroxaban

89
Q

2nd line anticoagulant in DVT if DOACs are not suitable?

A

LMWH

90
Q

1st line anticoagulation in DVT if patient has severe renal impairment (e.g. < 15/min)?

A

LMWH

91
Q

1st line anticoagulation in DVT if patient has antiphospholipid syndrome?

A

LMWH

92
Q

What are the options for long term anticoagulation in DVT?

A

1) DOACs
2) LMWH
3) Warfarin

93
Q

What is the anticoagulant of choice in DVT in pregnancy?

A

LMWH

94
Q

How long should patient be anticoagulated for following a DVT?

A

Depends on whether it was provoked or unprovoked.

Provoked –> 3 months (3 to 6 months for people with active cancer)

Unprovoked –> 6 months

95
Q

What are the 2 main complications of a DVT?

A

1) PE

2) post thrombotic syndrome

96
Q

What is post thrombotic syndrome?

A

Complications following a DVT –> venous outflow obstruction and venous insufficiency result in chronic venous hypertension.

The resulting clinical syndrome is known as post-thrombotic syndrome.

97
Q

What features may be seen in post-thrombotic syndrome?

A

1) painful, heavy calves

2) pruritus

3) swelling

4) varicose veins

5) venous ulceration

98
Q

What are the 2 main methods of VTE prophylaxis in hospital?

A

1) mechanical

2) pharmacological

99
Q

What are the 2 methods of mechanical thromboprophylaxis?

A

1) Antiembolic stockings (AES)

2) Intermittent pneumatic compression (IPC, more commonly used in theatre)

100
Q

What is the typical pharmacological VTE prophylaxis?

A

LMWH

101
Q

What is the typical pharmacological VTE prophylaxis in renal impairment (eGFR <30)?

A

UH

102
Q

Who are anti-embolic stockings contraindicated in?

A

1) suspected or proven peripheral arterial disease

2) periipheral arterial bypass grafting

3) peripheral neuropathy or other causes of sensory impairment

4) any local conditions in which anti-embolism stockings may cause damage e.g. fragile ‘tissue paper’ skin, dermatitis, gangrene or recent skin graft

5) severe leg oedema

103
Q
A