[Intradermal tests using vasomotor agents in allergic rhinitis]

Allergic rhinitis is characterised by nasal hyperactivity to specific and non-specific agents. For research purposes, non-specific nasal hyperactivity can be estimated by histamine and metacholine nasal challenge tests. At present, nasal challenge tests are not used for routine diagnosis of rhinitis. Wayoff and colleagues proposed the examination of the skin reactivity to papaverine, acetylcholine, histamine and compound 48/80 in rhinitis patients. Our previous study of skin reactivity to vasomotor agents, using modified skin tests of Wayoff and colleagues showed their clinical validation and usefulness for subclassification of patients with non-allergic rhinitis. To the present, there are only a few studies of skin reactivity to vasomotor agents in patients with allergic rhinitis. The aim of this study was to examine the skin reactivity to vasomotor agents of allergic rhinitis patients and determine whether the patients with allergic rhinitis differ from healthy subjects.

A prospective, controlled, in vivo study was carried out in 86 subjects: 44 patients with allergic rhinitis and 42 healthy subjects. Skin reactivity was examined by intradermal tests with different concentrations of papaverine, metacholine, histamine and compound 48/48. The non-specific skin reactivity to saline was also measured. Skin reactivity to intradermal test with different concentrations of papaverine, metacholine, histamine and compound 48/48 was measured, as well as specific skin reactivity to control saline solution. Pathological skin reactivity to vasomotor agents was defined as follows: hyporeactivity to papaverine (5 mg/mL), when wheal-and-flare skin reaction diameter was less than 15 mm; hyper-reactivity to metacholine (0.02, 0.2 and 2.0 mg/mL), when two of three wheal-and-flare skin reaction diameters were greater than 15, 25 and 31 mm, respectively; hyper-reactivity to histamine (0.01, 0.1, 1.0 and 10.0 mg/mL), when three of four wheal-and-flare skin reaction diameters were greater than 7, 13, 25 and 40 mm, respectively; and hyper-reactivity to compound 48/80 (0.01, 0.1, 1.0 and 10.0 mg/mL), when three of four wheal-and-flare skin reaction diameters were greater than 9, 16, 26 and 38 mm, respectively.

The study included 86 subjects: 44 patients with allergic rhinitis and 42 healthy subjects. The control group of healthy subjects consisted of 22 females, aged from 18 to 35 yrs (mean 28 yrs), and 20 males, aged from 18 to 40 yrs (mean 28 yrs). The difference between the number [p(= 0.758) > 0.05] and age [p(= 0.990) > 0.05] of females and males was not significant. In the allergic rhinitis patients group, there were 23 females, aged from 18 to 54 yrs (mean 33 yrs) and 21 males, aged from 18 to 50 yrs (mean 36 yrs). The difference between the number [p(= 0.763) > 0.05] and age [p(= 0.558) > 0.05] of females and males was not significant. Frequencies of pathological skin reactivity to single vasomotor agents and saline in the control group of healthy subjects and in the allergic rhinitis patients group are shown in Table 1. In the control group, frequencies of normal skin reactivity to papaverine [p(= 1.8 x 10(-7)) < 0.01], metacholine [p(= 4.3 x 10(-6)) < 0.01], histamine [p(= 4.3 x 10(-6)) < 0.01], compound 48/80 [p(= 1.8 x 10(-7) < 0.01] and saline [p(= 6.9 x 10(-4)) < 0.01] were significantly greater than frequencies of pathological skin reactivity. In the patients group, frequencies of normal skin reactivity to papaverine [p(= 6.0 x 10(-8)) < 0.01] and saline [p(= 2.6 x 10(-3) < 0.01] were significantly greater, and to metacholine [p(= 0.016) < 0.05] were significantly greater than frequencies of pathological skin reactivity. In this group, the difference between frequencies of pathological skin reactivity to histamine [p(= 0.366) > 0.05] and compound 48/80 [p(= 0.070) > 0.05] were not significant. There was no significant intergroup difference for pathological skin reactivity to papaverine, metacholine and saline (Table 1). In the patients group frequencies of pathological skin reactivity to histamine and compound 48/80 were significantly higher than in the control group of healthy subjects. Frequencies of pathological skin reactivity to single vasomotor agents and in combinations in the control group of healthy subjects and in the allergic rhinitis patients group are shown in Table 2. The difference of pathological skin reactivity to single vasomotor agents and in combinations between the control group (14/42) and the allergic rhinitis patients group (27/44) was significant [p(= 0.017) < 0.05].

In routine evaluation of the rhinitis patients, skin tests with vasomotor agents have some advantages: these tests do not require special equipment, they are not time-consuming, they are easy to perform and simple for the interpretation of results. (ABSTRACT TRUNCATED)