Table Other causes of nasolacrimal drainage stricture or obstruction include Burns Chemotherapy drugs Eye drops (particularly echothiophate iodide, epinephrine, and pilocarpine) Infection, including canaliculitis (eg, caused by Staphylococcus aureus, Actinomyces, Streptococcus, Pseudomonas, herpes zoster virus, herpes simplex conjunctivitis, infectious mononucleosis, human papillomavirus, Ascaris, leprosy, tuberculosis) Inflammatory disorders (sarcoidosis, granulomatosis with polyangiitis [formerly called Wegener granulomatosis]) Injuries (eg, nasoethmoid fractures; nasal, orbital, or endoscopic sinus surgery) Obstruction of nasal outlet despite an intact nasolacrimal system (eg, upper respiratory infection, allergic rhinitis, sinusitis) Radiation therapy Stevens-Johnson syndrome Tumors (eg, primary lacrimal sac tumors, benign papillomas, squamous and basal cell carcinoma, transitional cell carcinoma, fibrous histiocytomas, midline granuloma, lymphoma) Evaluation of Tearing History History of present illness addresses the duration, onset, and severity of symptoms, including whether tears drip down the cheek (true epiphora).