[Conjunctival provocation test with Dermatophagoides pteronyssinus in the diagnosis of allergic conjunctivitis from house mites].
BACKGROUND
Perennial conjunctivitis due to house dust mites is the most frequent form of allergic conjunctivitis in urban environments. However, its diagnosis remains difficult for ophthalmologists. In this study, we evaluated a conjunctival provocation test (CPT) using standardized extracts of Dermatophagoides pteronyssinus (Dpt) and compared it to the diagnostic methods commonly performed in allergology: prick tests with dust and house dust mites and specific and IgE assay.


METHODS
We performed a CPT on 60 volunteer patients, between the ages of 8 and 64 years, corresponding to 30 patients sensitized to house dust mites with the presence of specific IgE and chronic conjunctivitis, 21 patients not sensitized to house dust mites but presenting features of chronic conjunctivitis, and 9 asymptomatic patients. A house dust mite desensitizing treatment was not an exclusion criterion for a number of allergic patients. CPTs were prepared from Dpt allergenic extracts (Laboratoires Stallergènes, Antony, France) with 5 progressive concentrations by dilution in a nonphenolic physiological solution: 1.2 RI, 3.7 RI, 11 RI, 33 RI, and 100 RI. CPTs were performed in only one eye and asymmetry of the ocular response was evaluated by the cumulative clinical score of Abelson Chambers and Smith. The correlation between the 2 diagnostic tests was established by calculating the Cohen correlation coefficient or kappa. We also evaluated the sensitivity and diagnostic specificity for each test.


RESULTS
The statistical correlation between specific IgE and the other allergological tests in for allergic conjunctivitis to house dust mites was 0.93 for the CPT, 0.46 for the prick test to Dpt, and 0.33 for the prick test to dust. The diagnostic sensitivities and specificities for each test were 90% and 100% for the CPT, 60% and 70% for the prick test to dust, 70% and 76% for prick test to Dpt, respectively. Beyond an antigenic cut-off value of 11 RI, we also observed greater hypersensitivity reactions for patients with lacrimal IgE or elevated specific IgE levels.


CONCLUSIONS
The results obtained with the CPT confirm its high antigenic quality. It is a particularly useful, rapid, and perfectly safe clinical test. It is the only test able to establish a relationship between ocular manifestations and specific I(8)E.
Bertel
F
F
Centre Jean Abadie, Service d'Ophtalmologie, 89, rue des Sablières, 33077 Bordeaux Cedex, France.
Mortemousque
B
B
Sicard
H
H
André
C
C
D000293:Adolescent; D000328:Adult; D000485:Allergens; D000818:Animals; D002648:Child; D003233:Conjunctivitis, Allergic / Q000175:diagnosis* / Q000276:immunology / Q000469:parasitology*; D004391:Dust; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis; D008297:Male; D008875:Middle Aged; D008925:Mites / Q000276:immunology*; D012680:Sensitivity and Specificity
D000485:Allergens; D004391:Dust; D007073:Immunoglobulin E