Phlyctenular keratoconjunctivitis

In the United States the most common cause of phlyctenular keratoconjunctivitis, also known as phlyctenulosis, is Staphylococcus aureus. S. aureus is a prevalent microbe, and its cell wall antigens have been proven to cause phlyctenulosis in rabbits. 

A course of oral tetracycline or erythromycin may be a reasonable treatment alternative for patients with chronic or recurrent phlyctenular keratoconjimctivitis. Some clinicians recommend 250 mg tetracycline three times daily for 3 weeks followed by 250 mg once daily for 2 months. In children under 8 years of age, erythromycin 25 mg/kg in four divided doses may be used. Additionally a recent study reported topical cyclosporine 2% as a safe and effective therapy for children with severe phlyctenular keratoconjunctivitis not responding to oral medications. 

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