Hyposensitization in the treatment of resistant cases of vernal keratoconjunctivitis

Purpose: The study evaluated the treatment of resistant cases of vernal keratoconjunctivitis by hyposensitization resulting from intradermal skin reactions of different allergens. Methods: This prospective study was carried out in the Department of Ophthalmology and the Department of Microbiology and Immunology, Zagazig University, and included 36 patients with bilateral vernal keratoconjunctivitis that was resistant to topical corticosteroids and antihistaminic drugs. Patients were subjected to intradermal skin reactions to different allergens after stoppage of the medication. Subcutaneous injections of different allergens were administered in addition to topical vasoconstrictor and antihistaminic eye drops for different durations of 12, 18, and 24 months. Results: The study revealed that most of the patients were sensitive to pollens (65\%), house dust (55\%), and tobacco smoke (40\%). Among 36 total patients who received different doses of allergens, 10 of 20 patients showed marked improvement following a 24-month treatment period, with a 50\% success rate. Another 3 of 9 patients showed marked improvement following an 18-month treatment period, with a 33.3\% success rate. Conclusion: The use of intradermal skin reactions to determine the sensitivity for different stimulating allergens in resistant cases of vernal keratoconjunctivitis was conclusive. Treatment by hyposensitization using prepared vaccines had an acceptable success rate especially in patients treated for 24 months. Future studies will be needed to determine how effective this treatment is with other allergens and for longer durations of hyposensitization. Additional immunologic studies will be essential for developing a strategy of management of resistance in such cases of resistant vernal keratoconjunctivitis.