The
wheals induced by histamine increase with age also in adult patients.
Nils
E Eriksson
Purpose.
Several factors influence the histamine reactivity. A positive correlation
between age and histamine skin reactivity has earlier been shown in children.
Earlier studies are, however, conflicting, as far as adult patients are
concerned. This study aimed at exploring the influence of age in adult patients
on the wheals induced by histamine.
Methods.
During the 25 years (1976-2000), we performed skin prick tests (SPT) in clinical
routine work on 14723 patients,
mainly adults with asthma or rhinitis. As a positive control we used histamine
HCl with a concentration of 1 g/lit., 3 g/lit or 10 g/lit. The mean of the
longest and the shortest diameters was used in the calculations. Patients with a
mean diameter less than 1 mm (n=123) were omitted from the calculations
Results.
There was no significant difference between atopic patients (patients having
positive SPT with common inhalant allergens) and non atopic patients. Nor were
there any significant correlations between histamine diameters and atopy degree
(the sum of plusses obtained with seven common inhalant allergens) or the number
of allergens showing positive SPT results. Males, however, had larger wheals
than females. With all the histamine concentrations used, an increase of wheal
diameter with the patients´ ages were seen. The figure shows the wheal
diameters related to age groups for tests performed with histamine 10 g/lit.
Conclusion.. There is an
increase of wheal size with age all age groups. Since the histamine skin
reactivity will influence the size of allergen-induced wheals, the patient’s
age should be taken into account, when evaluating SPT results with allergens.
The method of evaluating SPT results, often used in Nordic countries, where the
allergen induced wheals size is expressed in relation to the size of the
histamine-induced wheal, is one way of taking into account the skin histamine
sensitivity
Diameters
in various age groups, means and Standard Error of Means (SEM)
|
Age
group (years) |
10
g/lit |
3
g/lit |
1
g/lit |
|||
|
|
Mean |
SEM |
Mean |
SEM |
Mean |
SEM |
| 15-20 |
5.48 |
0.05 |
4.61 |
0.08 |
4.08 |
0.04 |
| 21-30 |
5.50 |
0.04 |
4.72 |
0.07 |
4.27 |
0.04 |
| 31-40 |
5.69 |
0.05 |
5.06 |
0.08 |
4.32 |
0.05 |
| 41-50 |
5.96 |
0.06 |
4.83 |
0.10 |
4.47 |
0.06 |
| 51-60 |
6.26 |
0.08 |
5.29 |
0.18 |
4.66 |
0.07 |
| >
60 yrs |
6.31 |
0.10 |
5.55 |
0.20 |
4.81 |
0.10 |
| Total |
5.75 |
0.02 |
4.88 |
0.04 |
4.32 |
0.02 |