Frozen fruit skin prick test for the diagnosis of fruit allergy.

BACKGROUND

Diagnosis of fruit sensitisation by skin prick test (SPT) is fast and easy to perform. Nevertheless, some fruit is not available throughout the year. Freezing aliquots of these fresh fruits to be defrosted would be a good solution to perform SPT at any time.

OBJECTIVE

To compare the reproducibility of SPT with Rosaceae and Cucurbitaceae frozen fruit with fresh and commercial fruit extracts.

METHODS

SPT with the following fruit were performed: apricot, cherry, strawberry, nectarine, Japanese medlar, peach, (peel and pulp), yellow and red plum, melon and watermelon. We compared fresh fruit, commercial extract and fruit which had been frozen at -18 degrees C. Results were read by planimetry (Inmunotek prick-film) after 15 minutes.

RESULTS

The study group comprised 48 patients (9 males, 39 females) with a mean age of 31, 6 +/- 2.0 years. Concordance of positive and negative results was extremely high and significant in all cases. Correlation between frozen fruit and commercial extract, frozen fruit and fresh and commercial extract and fresh fruit was statistically significant in all cases except for strawberry.

CONCLUSIONS

The use of frozen fruit is a valid method, as the performance of the SPT is similar to that of fresh fruit. This enables diagnostic procedures with seasonal fruit at any time of the year.