Which organism is classically associated with canaliculitis presenting with sulfur granules?

Which organism is classically associated with canaliculitis presenting with sulfur granules?

• A. Staphylococcus aureus
• B. Actinomyces israelii
• C. Pseudomonas aeruginosa
• D. Streptococcus pyogenes

Answer: (B)

Sulfur granules in canaliculitis point to Actinomyces israelii. This organism is a filamentous, gram-positive bacterium that often causes actinomycosis. In the lacrimal drainage system, Actinomyces forms yellowish, sulfur-like granules that can be expressed from the punctum along with chronic discharge and swelling. Other common canaliculitis pathogens don’t typically produce these granules, so the presence of sulfur granules makes Actinomyces israelii the best fit.