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Background:
Chronic urticaria
(CU) is a skin
disorder
characterized by
long-lasting release
of histamine, and
sometimes
leukotrienes, from
both mast cells and
basophils. Although
both these
substances are
potent inductors of
contraction of
airway smooth muscle,
pulmonary function
and airway
hyperresponsiveness
have not been
systematically
investigated in
patients with CU.
Objective: To
assess pulmonary
function and airway
hyperresponsiveness
in patients with CU.
Methods: Twenty-six
clinically well-characterized
adult patients with
CU (M/F 8/18; mean
age 47 years)
underwent pulmonary
function tests and
methacholine
provocation during a
phase of moderate
activity of their
disease. Twenty-six
adult asthmatic
patients submitted
to methacholine
provocation were
used as controls.
Results: Two
patients (8%) had
overt asthma on
baseline pulmonary
function tests.
Twenty (77%)
patients with a
normal baseline
pulmonary function
showed significant
bronchial
hyperresponsiveness
on methacholine
provocation.
Altogether, 22/26
(85%) patients had
asthma or abnormal
bronchial reactivity.
Airway
hyperresponsiveness
was not associated
with gender, disease
duration,
intolerance to NSAID,
positive autologous
serum skin test or
respiratory allergy.
On average,
asthmatic controls
showed a much
severer airway
hyperresponsiveness
than urticaria
patients (p< 0.01).
Conclusion:
Patients with CU
frequently show
bronchial
hyperresponsiveness.
Prospective studies
are needed to assess
whether they are at
risk for bronchial
asthma.
Key words:
Chronic urticaria,
asthma, airway
hyperresponsiveness,
methacholine,
histamine. |
