Orbital Cellulitis

Question 1

Intro

Answer 1

Orbital cellulitis is defined as a serious infection that involves the muscle and fat located within the orbit.

Question 2

Causative organisms

Answer 2

A) Bacterial :

1. Streptococcus pneumoniae
2. Streptococcus pyogenes
3. Staphylococcus aureus
4. Haemophilus influenzae
5. Gram-negative bacteria: In some cases, gram-negative bacteria, such as Escherichia coli, Klebsiella pneumoniae, or Pseudomonas aeruginosa,

B) fungal:

1. Aspergillus
2. Mucorales
3. Candida
4. Fusarium

Question 3

Diagnosis

Answer 3

A) H&E

• pain with eye movements
• proptosis
• ophthalmoplegia with diplopia.
• Chemosis (conjunctival swelling) is more commonly present in orbital cellulitis; however, it may also be seen occasionally in severe cases of preseptal cellulitis.
• Fever and peripheral leukocytosis with a predominance of neutrophils are also seen in orbital cellulitis.
• Eyelid erythema may or may not be present

B) Lab studies
1- cbc
2- blood cultures

C) Imaging Studies

CT and MRI

• MRI has been found to be superior to CT scan because it can help in following soft tissue disease progression .
• Common CT findings in orbital cellulitis are inflammation of extraocular muscles, fat stranding, and anterior displacement of the globe,

Complications of orbital cellulitis, for example, subperiosteal abscesses and orbital abscesses appear as low-density collections on CT scan.

Question 4

Treatment / Management

Answer 4

Uncomplicated orbital cellulitis can be treated with antibiotics alone. Treatment regimens are usually empiric and designed to address the most common pathogens as described above because reliable culture results are difficult to obtain in the absence of surgical intervention. For patients with uncomplicated orbital cellulitis, it is suggested that antibiotics be continued until all signs of orbital cellulitis have resolved. The duration of antibiotic therapy ranges from a total of at least 2 to 3 weeks. For patients with severe ethmoid sinusitis and bony destruction of the sinus, a longer period, at least 4 weeks is recommended

Appropriate antibiotic regimens for empiric treatment in patients with normal renal function include:

A) Intravenous (IV) Therapy:-
1- Vancomycin For MRSA coverage
Children: 40 to 60 mg/kg per day IV divided into 3 or 4 doses; Maximum daily dose 4 g Adults: 15 to 20 mg/kg per day IV every 8 to 12 hours; Maximum 2 g for each dose

Plus one of the following:
- Ceftriaxone
Children: 50 mg/kg per dose IV once or twice per day (the higher dose should be used if an intracranial extension is suspected); Maximum daily dose 4 g per day
Adults: 2 g IV per day (2 g IV every 12 hours if an intracranial extension is suspected)

• Cefotaxime
  Children: 150 to 200 mg/kg per day in 3 doses; Maximum daily dose 12 g Adults: 2 g IV every 4 hours
• Ampicillin-sulbactam
  Children: 300 mg/kg per day in 4 divided doses; Maximum daily dose 8 g of the ampicillin component
  Adults: 3 g IV every 6 hours of the ampicillin-sulbactam combination
• Piperacillin-tazobactam
  Children: 240 mg/kg per day in 3 divided doses; Maximum daily dose 16 g of the piperacillin component
  Adults: 4.5 g IV every 6 hours of the piperacillin-tazobactam combination
• Metronidazole
  Should be added to include coverage for anaerobes.
  Adults: 500 mg IV or orally every 8 hours
  Children: 30 mg/kg per day IV or orally in divided doses every 6 hours

In case of allergy to penicillins and/or cephalosporins, treatment with a combination of

• vancomycin plus:
• Ciprofloxacin
  Adults: 400 mg IV twice per day or 500 to 750 mg orally twice per day
  Children: 20 to 30 mg/kg per day divided every 12 hours; Maximum dose of 1.5 g orally daily or 800 mg IV daily
• Levofloxacin
  Adults: 500 to 750 mg IV or orally daily
  Children 5 years or older: 10 mg/kg per dose every 24 hours; Maximum daily dose 500 mg
  Infants 6 months or older and children 5 years or younger: 10 mg/kg per dose every 12 hours

B) Oral Therapy

• Clindamycin (alone)
  Adults: 300 mg Q8H
  Children: 30-40 mg/kg per day in 3 to 4 equally divided doses, not to exceed 1.8 g per day

-Clindamycin or Trimethoprim-Sulfamethoxazole
Adults: 1 to 2 DS tablets every 12 hours
Children: 10 to 12 mg/kg per day of the trimethoprim component divided every 12 hours

Plus one of the following:
- Amoxicillin
Adults: 875 mg orally every 12 hours
Children: 45 mg/kg per day in divided doses every 12 hours or 80 to 100 mg/kg per day in divided doses every 8 hours; Maximum dose 500 mg per dose

• Amoxicillin-clavulanic
  Adults: 875 mg every 12 hours
  Children: 40 to 45 mg/kg per day in divided doses every 8 to 12 hours or 90 mg/kg per day divided every 12 hours (600 mg/5 mL suspension)
• Cefpodoxime
  Adults: 400 mg every 12 hours
  Children: 10 mg/kg per day divided every 12 hours, not to exceed 200 mg per dose
• Cefdinir
  Adults: 300 mg twice daily
  Children: 7 mg/kg twice daily, not to exceed 600 mg per day

Question 5

Complications

Answer 5

1. Abscess
2. Vision loss: Orbital cellulitis can affect the optic nerve.
3. Cavernous sinus thrombosis.
4. Meningitis.