OBJECTIVE: To determine the prevalence of symptoms and signs of allergic rhinitis (AR) in children with vernal keratoconjunctivitis (VKC) and evaluate eustachian tube (ET) function using tympanometry. METHODS: The patients underwent an otolaryngological examination and symptoms of rhinorrhoea, nasal obstruction, nasal itching and sneezing were evaluated for the diagnosis of AR. Tympanometry was performed by a middle ear analyzer (Impedance audiometer AZ 26, Interacoustics A/S, Assens, Denmark). Blood samples were collected for determination of peripheral blood eosinophil count (PBEC) and serum total immunoglobulin E (IgE). Allergen sensitivity was also determined by skin prick test. RESULTS: The study included 26 males (96.3%) and 1 female (3.7%) with a mean age of 12.1+/-4.4 years. Eight out of 27 subjects (29.6%) had blood eosinophilia and 11 out of 27 subjects had elevated serum IgE (40.7%). A positive skin prick test was identified for at least one allergen in 40% of patients (10/25 subjects). Symptoms and signs of AR were found in 10 subjects (37%). Median serum IgE level in subjects with AR (262.5kU/L) was higher than without AR (40.2kU/L) (p=0.08), whereas there were no differences in PBEC or eosinophilia percentage (p>0.05). Mean middle ear pressures in the right and left ears were -66.4daPa (range between -268 and 4daPa) and -57.3daPa (range between -308 and 0daPa), respectively. The tympanometry results were abnormal in 5 subjects (18.5%) (3 type C and 2 type B tympanogram). Three out of 10 VKC patients with AR (30%) and 2 out of 17 VKC patients without AR (11.8%) had abnormal tympanograms (p=0.33). CONCLUSION: AR is commonly associated with VKC and subjects with AR are almost three times more likely to have ET dysfunction than those without. Therefore, opthalmologists should refer VKC patients to otolaryngologists to delineate associated AR and ET dysfunction. Conversely, patients with OME and/or AR who have persistent allergic eye symptoms may well benefit from opthalmologic evaluation for seasonal allergic conjunctivitis and VKC.