[Values of intradermal skin test and serum sIgE detection in diagnosing Humulus scandens pollinosis].

OBJECTIVE

To evaluate the values of intradermal skin test (IDT) and serum specific IgE detection in diagnosing Humulus scandens sensitivity in Chinese patients with autumnal hay fever.

METHODS

1150 patients, 504 males and 646 females, aged 5 approximately 75, were evaluated as with autumnal rhinitis and asthma by experienced physicians. Then the patients underwent IDT by using 20 kinds of aeroallergen extracts, at the concentration of 1:1000 (w/v) for Artemisia spp. and ragweed or at the concentration of 1:100 (w/v) for Humulus scandens and others. The Humulus sIgE level was performed in all patients. A diagnosing criteria was established according to typical history, symptoms, and any one of the following findings: (1) wheal > or = 5 mm in diameter by IDT and sIgE to Humulus of the concentration > or = 0.35 kUa/L at same time; (2) wheal > or = 10 mm in diameter by IDT alone; and (3) sIgE to Humulus of the concentration > or = 0.70 kUa/L alone.

RESULTS

When using the above diagnosing criteria as the reference standard, IDT had better sensitivity (97.2%), positive predictive value (PV+) (77.9%), negative predictive value (PV-) (90.6%) and efficiency (80.4% than using sIgE > or = 0.35 kUa/L alone as the reference criteria of IDT, however, had a lower specificity (49.8%); and sIgE detection had better sensitivity (89.0%), specificity (97.5%), PV+ (98.8%), PV- (88.0%) and efficiency (92.0%) than using wheal > or = 5 mm in diameter alone as the reference criteria of sIgE detection. The false positive rate of IDT decreased from 59.9% to 17.4% when using wheal diameter > or = 10 mm as the positive criteria. In the 288 patients with a negative sIgE result and a positive IDT result 84 cases had stronger positive IDT result (with the wheal diameter > or = 10 mm).

CONCLUSIONS

IDT is correlated well with sIgE detection in diagnosing Humulus scandens pollinosis, but the false positive rate of IDT is higher than that of sIgE test. The false positive rate of IDT can be decreased by increasing the positive criteria to higher grading reaction. The immunotherapy according to the lower grading positive result of IDT alone or sIgE alone should be avoided.