RESUMO
Total tear IgE has been considered to play an important role in allergic conjunctivitis, and measurement has been considered useful for diagnosis. The aim of this study was to ascertain whether Lacrytest(®), a new commercialised method to detect IgE levels in lacrimal fluid, could constitute a screening test for the diagnosis of allergic conjunctivitis. This was a cross-sectional study. Patients with seasonal and perennial allergic conjunctivitis, vernal keratoconjunctivitis and a control group were included. Clinical history, ophthalmic examination, skin prick test and conjunctival provocation test were obtained. Lacrytest(®) was later performed in all groups. Fifty-four patients were enrolled: thirty with IgE-mediated conjunctivitis and, nine with vernal keratoconjunctivitis and fifteen controls. Lacrytest(®) was negative in all controls, positive in 20% of the IgE-mediated conjunctivitis group and in 88.9% of the vernal keratoconjunctivitis group. Global statistically-significant differences were found among the three groups (P = .003). Sensitivity of the test in the IgE-mediated conjunctivitis group was 20%, specificity 100%, positive predictive value 100%, and negative predictive value 38.46%, while in VKC sensitivity was 88.88%, specificity 100%, positive predictive value 100%, and negative predictive value 93.75%. Our data confirm that this test is not useful for screening allergic conjunctivitis. Lacrytest(®), while not providing any useful information to an allergist, could be helpful for ophthalmologists to confirm an IgE-mediated or VKC conjunctivitis.
RESUMO
BACKGROUND: Mattresses and bedding are the main reservoirs of house dust mites. OBJECTIVE: Subjects sleeping in the bottom bunk may be exposed to house dust particles detached from bedding of the top bunk. Our aim was to ascertain whether this exposure could influence the development of mite sensitization and/or allergic symptoms in these individuals. METHODS: Symptoms of allergic respiratory disease were recorded and mite skin tests performed in 94 consecutive bunk-sleeping subjects (47 pairs of siblings) from an outpatient allergy clinic. Levels of Der p I, Der f I, and Der II were determined by enzyme-immunoassay in 16 randomly selected bedding dust samples (8 pairs of bunks). RESULTS: Mite sensitization rate and prevalence of allergic respiratory disease were similar for the top-bed and bottom-bed groups, whereas prevalence of asthma was significantly higher in the latter. Mite sensitization was significantly associated with family atopy background, whereas other factors such as house pets, indoor smoke exposure or types of mattress or bunks were not. Der p I levels higher than 2 microg/g dust were found in 12 of the 16 mattresses and the median of the 8-bed-bottom group was over 10 microg/g. CONCLUSIONS: Sleeping in bunks constitutes a greater risk of developing asthma for subjects sleeping in the bottom bed. Bunk sleeping should be discouraged in families with an atopic background and sensitized subjects should use the top bed.
