Bacterial: Cellulitis, Vasculitis, Erysipelas, Impetigo

Question 1

Define/causes of cellulitis?

Answer 1

Bacterial soft tissue infection of the dermis and subcutaneous tissue.

Caused by Streptococcus and/or Staphylococcus organisms.

Gram-positive bacteria.

Question 2

Presentation of cellulitis?

Answer 2

Red
Hot (calor)
Swelling
Pain
Fever
Poorly demarcated margins
Lymphadenopathy
Rarely blisters and pustules (severe disease)
Often evidence of breach of skin barrier e.g. trauma, ulcer etc.

Question 3

Diagnosis/IVx of cellulitis?

Answer 3

Bloods:
- FBC (high WCC)
- CRP
- U&Es
- blood cultures

Wound swab (if present)

US scan (distinguishing nonpurulent cellulitis from cellulitis with underlying abscess and for identifying drainable fluid collection)

Question 4

Management of cellulitis?

Answer 4

Mild cases:
- Flucloxacillin
- Clindamycin
- Doxycycline
- Co-amoxiclav

Admission for IV abx:
- systemically unwell/unstable
- sepsis
- necrotizing fasciitis
- redness spreads
- periorbital/orbital cellulitis

Consider tetanus prophylaxis if traumatic (5 in a lifetime)

Question 5

How is cellulitis classified?

Answer 5

Eron classification
Class I = no toxicity
Class II = systemically unwell/well with a comorbidity
Class III = systemically unwell with unstable comorbidities or limb-threatening infection.
Class IV = sepsis or severe life-threatening infection

Question 6

Define/causes of vasculitis?

Answer 6

Inflammation of blood vessels.

Cause unknown.
Associated with:
- autoimmune disorders
- IBD
- hypersensitivity
- joints may be affected

Question 7

Presentation of vasculitis?

Answer 7

Itching, burning purpuritic rash
Can be drug reaction (e.g. NSAIDs, abx)
1-3mm lesions, may coalesce
Found on legs commonly

Question 8

Diagnosis/IVx of vasculitis?

Answer 8

Clinical diagnosis

Question 9

Management of vasculitis?

Answer 9

Treat underlying cause

Compression stockings, elevate leg.

Sedating antihistamine.

Colchicine/Dapsone if no systemic involvement.

High-dose steroid if systemic involvement +/- methotrexate, azathioprine

Question 10

Define/causes of erysipelas?

Answer 10

Infection of the dermis and upper subcutaneous tissue.

Cause -Group A Strep

Question 11

Presentation of erysipelas?

Answer 11

Borders are sharply defined.

Affected skin is raised, swollen, firm, red (FIERY RED SKIN; STREAKING), and itchy.

BUTTERFLY DISTRIBUTION over the cheeks and bridge of the nose.

Commonly affects lower limbs.

If face affected, source of infection is the nasopharynx.

Question 11

Diagnosis of erysipelas?

Answer 11

Clinicial diagnosis

May do blood tests, culture if site of skin breaks, imagining if bone is involved.

Question 11

Management of erysipelas?

Answer 11

Supportive care
Analgesia

Abx:
- Flucloxacillin (erythromycin if penicillin allergy)

If facial:
- offer co-amoxiclav and ADMIT pt

Question 12

Define/causes of impetigo?

Answer 12

Highly contagious superficial epidermal infection of the skin.

Caused by Staphylococcal aureus and Group A Streptococcal bacteria.

These bacteria can invade the skin through minor cuts, insect bites, or abrasions, leading to infection.

Question 13

Presentations of impetigo?

Answer 13

Erythematous macule that vesiculates or pustulates.

Superficial erosion with a golden crust.

May be bullous (LARGE BLISTERS) or non-bullous (SORES)

Question 14

Diagnosis/IVx of impetigo?

Answer 14

Clinical diagnosis

May do skin swab for MC&S if tx resistant or recurrent infections.

Question 15

Management of impetigo?

Answer 15

Localised non-bollus impetigo:
- topical tx with hydrogen peroxide 1% cream (1ST LINE) for 5 days
- fusidic acid or mupirocin (2ND LINE)

Widespread non-bullous impetigo:
- 1ST LINE: topical (fusidic acid/mupirocin) or oral (flucloxacillin) for 5 days
- Clarithromycin (penicillin-allergic) or erythromycin (pregnancy)

Bullous impetigo or impetigo in those systematically unwell or at high risk complications:
- oral abx as above for 7 days