Please confirm topic selection

Are you sure you want to trigger topic in your Anconeus AI algorithm?

Please confirm action

You are done for today with this topic.

Would you like to start learning session with this topic items scheduled for future?

Review Question - QID 214787

In scope icon M 6 A
QID 214787 (Type "214787" in App Search)
A 25-year-old man presents to the emergency department for right eye pain. A few hours prior to presentation the patient was cleaning his backyard. After placing a metal crate full of wood and rocks onto the ground he felt a small object fall into his right eye. Since then, he has been unable to open his eye due to pain. He does not wear glasses or contact lenses and has no other medical history. His temperature is 98.6°F (37.0°C), blood pressure is 125/70 mmHg, pulse is 80/min, and respirations are 13/min. On physical exam, there is conjunctival erythema and upper eyelid edema. His right pupil appears miotic but is reactive to light. He has a visual acuity of 20/20 in the left eye and 20/30 in the right eye. Ophthalmology is consulted, and there is evidence of a corneal abrasion appreciated with fluorescein dye. Topical anesthesia is applied to the right eye, and the patient undergoes irrigation. Which of the following is most likely to be found on microbiological testing of the corneal foreign body?

Coagulase-negative, gram-positive cocci

29%

2/7

Facultative anaerobic gram-positive bacilli

14%

1/7

Gram-negative diplococci

14%

1/7

Oxidase-positive, non-lactose fermenting, gram-negative bacilli

29%

2/7

Weakly acid-fast, gram-positive branching filamentous bacilli

14%

1/7

Select Answer to see Preferred Response

bookmode logo Review TC In New Tab

This patient developed a corneal abrasion secondary to a foreign body. The most common pathogen seen in the culture of a corneal foreign body is coagulase-negative, gram-positive cocci (staphylococci).

A corneal abrasion occurs when there is disruption of the corneal epithelium secondary to mechanical trauma to the eye (a foreign body). Patients typically present with severe eye pain, photophobia, and foreign body sensation in the eye. Patients may have reactive miosis in the affected eye and difficulty opening the eye due to pain. Fluorescein dye will highlight the corneal defect. Cultures are rarely obtained from the corneal foreign body; however, the most common pathogen grown is coagulase-negative staphylococci. Other common organisms include streptococci, Pseudomonas aeruginosa, and Haemophilus species. The treatment of choice is irrigation of the eye and empiric topical antibiotics (erythromycin ointment or trimethoprim-polymyxin B).

Gupta et al. studied ocular injuries caused by foreign bodies. The authors found that since most foreign bodies are metal and enter the eye at high speed, most (roughly 2/3) become lodged in the posterior segment. The authors recommend that recent advancements in surgical techniques should be implemented to limit morbidity in patients with ocular foreign bodies.

Incorrect Answers:
Answer 2: Facultative anaerobic gram-positive bacilli can be seen in Listeria monocytogenes infection, which can result in septicemia, spontaneous abortion in pregnancy, and meningitis in patients who are immunocompromised.

Answer 3: Gram-negative diplococci describe Neisseria gonorrhoeae infection. This pathogen can result in bacterial keratitis. Infection is spread through sexual contact or a fetus passing through the birth canal.

Answer 4: Oxidase-positive, non-lactose fermenting, gram-negative bacilli describe a Pseudomonas aeruginosa infection. Pseudomonas infection of the eye is most likely to appear in patients who use contact lenses.

Answer 5: Weakly acid-fast, gram-positive branching filamentous bacilli describe a Nocardia infection, which can result in pulmonary and central nervous system infections in immunocompromised patients.

Bullet Summary:
The most common pathogen seen in corneal foreign body cultures is coagulase-negative, gram-positive cocci (staphylococci).

REFERENCES (2)
Authors
Rating
Please Rate Question Quality

3.5

  • star icon star icon star icon
  • star icon star icon star icon
  • star icon star icon star icon
  • star icon star icon star icon
  • star icon star icon star icon

(4)

Attach Treatment Poll
Treatment poll is required to gain more useful feedback from members.
Please enter Question Text
Please enter at least 2 unique options
Please enter at least 2 unique options
Please enter at least 2 unique options