Multi-Test® II

Purpose of study:

"To determine whether a skin test (ST) profile of negative percutaneous tests with positive ID [intradermal] tests (-/+ST) correlated with positive nasal challenges (NC)."

Results:

"Of 76 subjects tested using Multi-Test II (MT-II) percutaneous and ID methods with six aeroallergens (alternaria, cat, mixed ragweed, trees, grasses, house dust mites), repeat STs confirmed 8 subjects with 12 -/+ST profiles to an aeroallergen."

"None of the 12 NCs performed in 8 -/+ST subjects were positive."

Conclusions:

"In our study, positive ID tests with corresponding negative MT-II tests did not identify any subjects with a positive NC. These findings indicate that when MT-II tests are negative, routine performance of ID tests is unlikely to identify clinically significant allergy."

"The reproducibility of the histamine reactions expressed as the standard deviation also revealed significant differences among devices. The variability of the Multi-Test [II] device was significantly less than that of the smallpox needle or the Duotip and DermaPIK by either method as well as the Quintest."

Multi-Test II had the lowest variability of all the devices used (CV = 12.7), including the following:

• Multi-Test II (Avg. combined arm and back) 12.7
• Quintest (Avg. combined arm and back) 26.4
• Smallpox needle (prick) 22.0
• DermaPIK (GreerPIK), prick 19.2
• DermaPIK (GreerPIK), twist 16.9

This study found DermaPIK twist to be traumatic to the skin, evoking substantial non-specific irritant response. DermaPIK twist had low specificity (35%) at a 3 mm wheal cutoff. Every other method, including DermaPIK prick, was at least 95% specific at a 3 mm level. Sensitivity and specificity for Multi-Test II was 100% and 97.5% respectively. [Lincoln Diagnostics' summary]

"The reproducibility of the histamine reactions expressed as the standard deviation also revealed significant differences among devices. The variability of the Multi-Test [II] device was significantly less than that of the smallpox needle or the Duotip and DermaPIK by either method as well as the Quintest."

Multi-Test II had the lowest variability of all the devices used (CV = 12.7), including the following:

This study found DermaPIK twist to be traumatic to the skin, evoking substantial non-specific irritant response. DermaPIK twist had low specificity (35%) at a 3 mm wheal cutoff. Every other method, including DermaPIK prick, was at least 95% specific at a 3 mm level. Sensitivity and specificity for Multi-Test II was 100% and 97.5% respectively.

"Thirty-six subjects, 6 males and 30 females, mean age 30.6 years (range 21-60), were skin tested with Multi-Test II and Quintest utilizing histamine (10 mg./ml.) at six sites and glycerosaline at two sites for each device."

"Mean wheal sizes from histamine were: Multi-Test II 7.7 mm, Quintest 5.3. Mean coefficient of variation: Multi-Test II 17.7%, Quintest 36.1%. Sensitivity and specificity at 3 mm. level of positivity: Multi-Test II 97.7% and 95.8%, Quintest 91.2% and 100%."

"For application of 40 tests . . . Quintest testing required 2.9 times more time than did Multi-Test II testing."

"Both devices had high sensitivity and specificity. Multi-Test II had better reproducibility, faster application and better subject acceptance than Quintest . . . The 14.7 cm length of Quintest (versus 6.9 cm length of Multi-Test II) may limit its usefulness in smaller subjects and children."