Skin prick tests and in vitro immunoassays with native spices and spice extracts.

BACKGROUND

Skin prick tests of native spices (commercial powdered spices) are common in patients with allergy to birch or mugwort pollen. Clinical symptoms from spices are infrequent but occasionally severe.

OBJECTIVE

To compare the skin prick test results with native spices and spice extracts and to determine the clinical relevance of test material.

METHODS

Skin prick tests with the native spices coriander, caraway, paprika, cayenne, mustard, and white pepper were made twice at 2-month to 2.9-year intervals in 49 patients. During the latter time, tests were also made with spice extracts and spice-specific serum IgE was measured.

RESULTS

The reproducibility of skin test results with native spices was 67% to 100%. Spice extracts, except white pepper, elicited positive skin test reactions in half those with positive reactions to native spices. Higher specific IgE concentrations (> or = 3.5 PRU/mL) were seen in cases where the skin tests were positive to the corresponding spices with 5% extracts of > 8 kD Mw. Three-fourths of the patients with positive skin tests to native spices were positive to birch pollen and one-half to a vegetable. Mild clinical symptoms from spices were reported by one-third.

CONCLUSIONS

Spice allergens partly crossreact with those of pollens and vegetables. A minority of spice allergens may give clinical symptoms. The > 8-kD 5% extracts may be relevant skin prick test materials for identifying patients at risk of developing severe symptoms from ingested spices.