Canaliculitis: Symptoms, Types, Causes and Treatment

Canaliculitis is a frequently misdiagnosed yet distinct and bothersome infection of the lacrimal canaliculi—the small channels that drain tears from the eye into the nose. Though uncommon, it can have a significant impact on patient comfort and quality of life due to its persistent symptoms and tendency for recurrence if not properly treated. In this article, we take an in-depth look at canaliculitis, outlining its main symptoms, types, causes, and the most effective treatments available, according to the latest clinical evidence.

Symptoms of Canaliculitis

When canaliculitis strikes, it often presents with subtle but progressively irritating symptoms that can be mistaken for other eye conditions. Recognizing these hallmark features is critical for early diagnosis and successful management.

Symptom	Description	Frequency/Notes	Source(s)
Epiphora	Excessive tearing	Most common symptom	1 4 5 12
Discharge	Mucopurulent or gritty matter	Frequently observed	1 2 5 12
Redness	Medial canthal inflammation	Localized to inner eyelid corner	2 4 11
Pouting punctum	Swollen, everted punctum	Classic, highly suggestive sign	2 4 5 12
Concretions	Yellowish “sulfur granules”	Visible in punctum/canaliculus	5 6 15
Swelling	Canalicular thickening	Palpable & visible in many cases	4 12
Regurgitation	Pus on pressure/syringing	Diagnostic sign	1 4 12

Table 1: Key Symptoms of Canaliculitis

Recognizing the Signs

Canaliculitis is notorious for masquerading as more common eye conditions, especially chronic conjunctivitis. Patients typically report:

• Persistent tearing (epiphora) and a sticky eye discharge, sometimes described as “gritty” or containing small yellowish particles (“sulfur granules”) 1 4 5 12 15.
• Localized redness and swelling at the inner corner of the eye (medial canthus), often accompanied by tenderness 2 4 11.
• A pouting punctum—where the opening of the canaliculus appears swollen and everted—is a classic, highly suggestive sign 2 4 5 12.
• On gentle pressure or irrigation (“syringing”) of the canaliculus, pus or concretions may be expressed, confirming the diagnosis 1 4 12.

Why Symptoms Are Often Missed

The overlap with conjunctivitis and other lid disorders leads to frequent misdiagnosis and delays in proper treatment. In addition, the symptoms can be chronic, lasting for months before the correct diagnosis is made 1 12 13. Clinicians should maintain a high index of suspicion, especially in patients with recurring or treatment-resistant “conjunctivitis.”

Types of Canaliculitis

Although canaliculitis may seem like a single disease, there’s diversity in its underlying causes and presentations. Understanding the types is essential for accurate treatment and prognosis.

Type	Distinguishing Features	Common Pathogens/Triggers	Source(s)
Primary	No prior surgery/foreign body	Mixed bacteria, Actinomyces	1 2 5 12 15
Secondary	Related to stents, plugs, trauma	Bacteria, fungi, biofilm	2 5
Chronic	Symptoms >6 months, persistent signs	Actinomyces, mixed flora	6 14 15
Acute	Sudden onset, more pronounced pain	Varies (Strep, Staph, others)	2 5 12

Table 2: Main Types of Canaliculitis

Primary Canaliculitis

This is canaliculitis arising in an otherwise healthy canaliculus, usually due to bacterial infection—most often by Actinomyces, Streptococcus, or Staphylococcus species 1 5 12 15. It is the most common type in the general population.

Secondary Canaliculitis

Secondary canaliculitis develops due to the presence of a foreign body (such as punctal plugs or lacrimal stents), trauma, or after surgery in the lacrimal drainage system. These foreign materials can serve as a nidus for infection and biofilm formation 2 5.

Chronic vs. Acute Presentations

• Chronic canaliculitis is characterized by symptoms persisting for months or even years, often with the formation of “sulfur granules” or concretions and swelling that doesn’t resolve with topical antibiotics 6 14 15.
• Acute canaliculitis presents more suddenly, often with pronounced pain, swelling, and discharge, but may still be misdiagnosed as conjunctivitis 2 5 12.

Causes of Canaliculitis

Understanding the causative agents underlying canaliculitis is crucial for selecting effective treatment. The disease is mostly infectious, but the spectrum of organisms and mechanisms is broadening with advancing diagnostics.

Cause/Agent	Description/Notes	Prevalence/Significance	Source(s)
Actinomyces species	Gram-positive anaerobe, forms concretions	Historically most common	1 6 7 8 15
Staphylococcus spp.	Gram-positive cocci	Increasingly common	1 5 12 13
Streptococcus spp.	Gram-positive cocci	Frequently isolated	1 5 12
Other bacteria	Includes Propionibacterium, Mycobacterium, Myroides	Less common, emerging	1 9 10 12
Mixed infections	Multiple organisms in synergy	Not uncommon	15
Fungi	Rare, mainly in immunocompromised	Uncommon	2 5
Foreign bodies	Plugs, stents, trauma	Cause secondary type	2 5

Table 3: Main Causes and Pathogens in Canaliculitis

Bacterial Pathogens

• Actinomyces species—particularly Actinomyces israelii—have long been recognized as the archetypal cause of canaliculitis. These bacteria are unique in their ability to form “sulfur granules” or concretions within the canaliculus, making them highly suggestive when present 1 6 7 8 15.
• Staphylococcus and Streptococcus species are increasingly reported and may now surpass Actinomyces as the most commonly isolated pathogens in some regions 1 5 12 13.
• Other bacteria—such as Propionibacterium, Arcanobacterium, Myroides, and even atypical mycobacteria—are rarely implicated but have been documented, especially in chronic or treatment-resistant cases 1 6 9 10 12.

Mixed and Secondary Infections

Mixed infections, where several types of bacteria co-exist and potentially synergize, are not uncommon, especially in chronic cases or those with foreign bodies 15. Secondary canaliculitis is often linked to implants or stents that harbor biofilms, supporting a wider array of organisms 2 5.

Fungal and Non-Infectious Causes

Fungal canaliculitis is rare and usually seen in immunocompromised individuals. Non-infectious causes (such as trauma or irritation from foreign bodies) may also predispose the canaliculus to infection 2 5.

Treatment of Canaliculitis

Successful management of canaliculitis hinges on both eradicating the infection and addressing any obstructive concretions or foreign bodies. The choice of therapy is guided by the severity, chronicity, and underlying cause.

Treatment	Description/Method	Success/Notes	Source(s)
Conservative	Topical/systemic antibiotics, expression	Low cure rate, frequent relapse	4 11 12
Curettage	Mechanical removal of concretions	High efficacy, low morbidity	3 4 6 14
Punctoplasty	Dilation/incision to aid curettage	Often combined with curettage	3 4 12
Canaliculotomy	Surgical opening of canaliculus	Gold standard for recalcitrant	5 12 13 15
Removal of foreign body	Extraction of plug/stent	Essential in secondary cases	2 5

Table 4: Key Treatment Approaches in Canaliculitis

Conservative (Medical) Therapy

• Topical and systemic antibiotics (such as penicillin or moxifloxacin) may be tried initially, especially in early or mild cases.
• However, cure rates are low (as little as 10–69%), and recurrence is frequent if concretions are not removed 4 11 12.

Mechanical Removal: Curettage and Punctoplasty

• Curettage—scraping out the infected material and concretions from the canaliculus—is highly effective, especially when combined with punctoplasty (surgical dilation or incision of the punctum to allow better access) 3 4 6 14.
• Minimally invasive procedures (like “one-snip punctoplasty”) allow removal of concretions with rapid recovery and high cure rates (upwards of 83–100%) 3 4 12.
• Thorough curettage alone may suffice, especially in chronic cases, with minimal complications 14.

Canaliculotomy

• In cases resistant to less invasive measures, canaliculotomy (surgical opening of the canaliculus) is considered the gold standard. This approach allows for direct access and thorough cleaning, yielding high rates of permanent cure 5 12 13 15.
• The risk of long-term side effects, such as excessive tearing (epiphora), is low, especially if the procedure is properly performed 13.

Removal of Foreign Bodies

• For secondary canaliculitis, extraction of the offending plug, stent, or foreign object is essential for cure. This is always combined with medical and/or surgical therapy 2 5.

Post-Treatment and Prognosis

• Most patients experience full resolution after appropriate intervention, particularly with surgical management 3 4 12 13.
• Recurrence is rare but can happen, especially if any concretions are left behind or if underlying risk factors are not addressed 1 5 12.

Conclusion

Canaliculitis, though uncommon, is an important cause of chronic tearing and discharge that is often overlooked or misdiagnosed. Early recognition and a targeted approach to treatment are crucial for preventing recurrence and restoring patient comfort.

Key Takeaways:

• Symptoms include persistent tearing, discharge, medial canthal redness, pouting punctum, and visible concretions. Regurgitation of pus or “sulfur granules” on pressure is a hallmark sign 1 4 5 12 15.
• Types include primary (spontaneous, infection-driven), secondary (foreign body-associated), as well as chronic and acute forms 1 2 5 6 12 14 15.
• Causes are mostly bacterial, with Actinomyces, Staphylococcus, and Streptococcus species leading. Mixed and atypical infections are also possible 1 5 6 7 8 9 10 12 13 15.
• Treatment is most effective when mechanical removal of concretions (via curettage, punctoplasty, or canaliculotomy) is combined with antibiotics. Conservative therapy alone is rarely sufficient for lasting cure 3 4 5 11 12 13 14 15.

For patients and clinicians alike, awareness of canaliculitis—and its stubborn nature—remains the cornerstone for timely diagnosis and effective care.