Conjunctiva and cornea: Morax-Axenfeld conjunctivitis: practice question

A Ophthalmology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Ophthalmology · Conjunctiva and cornea: Morax-Axenfeld conjunctivitis

Sample item

A man with chronic angular blepharoconjunctivitis has macerated skin at the outer canthi. A smear shows large Gram-negative diplobacilli. Which organism is responsible?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

B. Moraxella lacunata

Angular blepharoconjunctivitis from Moraxella lacunata (Morax-Axenfeld diplobacillus) is a chronic condition that responds to zinc sulphate drops or topical antibiotics. Staphylococcus can cause angular disease too, but it is a Gram-positive coccus.

Option by option

  • A. Neisseria gonorrhoeae

    Neisseria gonorrhoeae is a Gram-negative diplococcus causing hyperacute purulent conjunctivitis.

  • B. Moraxella lacunata (correct)

    Correct. Moraxella lacunata is a Gram-negative diplobacillus causing angular conjunctivitis.

  • C. Haemophilus influenzae

    Haemophilus influenzae is a small Gram-negative coccobacillus causing acute mucopurulent conjunctivitis.

  • D. Staphylococcus aureus

    Staphylococcus aureus is a Gram-positive coccus in clusters.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

More Ophthalmology questions

Questions about this Ophthalmology question

What is the answer to this Ophthalmology question?

The best answer is B, Moraxella lacunata. Angular blepharoconjunctivitis from Moraxella lacunata (Morax-Axenfeld diplobacillus) is a chronic condition that responds to zinc sulphate drops or topical antibiotics.

Why is "Neisseria gonorrhoeae" not the answer?

Neisseria gonorrhoeae is a Gram-negative diplococcus causing hyperacute purulent conjunctivitis.

Why is "Haemophilus influenzae" not the answer?

Haemophilus influenzae is a small Gram-negative coccobacillus causing acute mucopurulent conjunctivitis.

Why is "Staphylococcus aureus" not the answer?

Staphylococcus aureus is a Gram-positive coccus in clusters.

What concept does this question test?

It tests Conjunctiva and cornea: Morax-Axenfeld conjunctivitis in Ophthalmology. Staphylococcus can cause angular disease too, but it is a Gram-positive coccus.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Conjunctiva and cornea: Morax-Axenfeld conjunctivitis?

Group the red eye by what to examine and what the pupil does. Then use the flashcards and the other Ophthalmology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.