Medico

Part II: Chronic Urticaria/Angioedema
The following Annotations are detailed explanations of the algorithm.
ANNOTATION 1: Does patient
exhibit skin lesions consistent with
chronic urticaria and/or
angioedema?
Urticaria is characterized by pruritic,
erythematous, blanching, circumscribed macular or raised lesions involving the superficial layers of skin.
Urticarial lesions classically waxand
wane and do not persist in a given
location for more than 24 hours. Such
lesions are defined as chronic if manifestations are persistent or recurring
over 6 weeks in duration (Fig. 1b).1–5
Persistent symptoms may be daily or
episodic (weekly, monthly, etc). Diurnal patterns are often reported but
these are highly variable from patient
to patient. It is not possible to predict
theduration of chronic urticaria/angioedema. Spontaneous remissions often
occur within 12 months but a substantial number of patients continue to
have symptoms at least periodically for
years. Conditions that can masquerade
as urticaria include but are not limited
to the following entities: erythema
multiforme minor, non-specific maculopapular exanthems, and mast cell releasability syndromes suchas urticaria
pigmentosa, (see Commentary 1 of
Acute Urticaria and Commentary 1
of Chronic Urticaria for details). Hypersensitivity vasculitis (ie., urticarial
vasculitis) should also be excluded6 –9
(see Annotations 4 – 6). The skin lesions of urticarial vasculitis present
with an urticarial appearance, but differ in that they persist 24 hours or
longer in the same area, and may be
palpableand purpuric. Following resolution, these lesions may leave residual pigmented changes in the skin. Urticarial vasculitis may be limited to the
skin or be part of a systemic disorder.1,6 On occasion, patients with pruritus alone are referred for urticaria
evaluation10 (see Commentary 1 for

532

ANNALS OF ALLERGY, ASTHMA, & IMMUNOLOGY

details). Angioedema involves swelling of deepsubcutaneous regions in
the skin and/or mucous membranes,
such as a finger, hand, lip, tongue etc.
There are many conditions that can
masquerade as angioedema that must
be considered when evaluating this
skin manifestation11 (see Commentary 1 of Acute Urticaria and Commentary 1 of Chronic Urticaria for
details).
ANNOTATION 2: Does patient
have chronic angioedema without
urticaria?
Commonly,patients experience the coexistence of chronic urticaria and angioedema. However, some patients
may present with chronic angioedema
without urticaria. Patients with this
manifestation fall into a separate category that may require diagnostic evaluations for unusual conditions11 (see
Annotation 3). The evaluation should
move to Annotation 4 if there is urticaria with angioedema.
ANNOTATION 3:Evaluation of
chronic angioedema without
urticaria
A detailed history, and physical examination are suggested to rule out underlying causes. Of particular importance
is the family history because of the
possibility of hereditary angioedema.
Etiologic triggers include medications
(eg, ACE inhibitors12) occupational exposure (eg, latex sensitivity)13; insect
sting reactions14,15; physicalhypersensitivity disorders (eg., cold urticaria
that can present with generalized or
regional angioedema following cold
exposure16); exercise-induced angioedema with or without anaphylaxis17,18; pressure-mediated sensitivity
that can cause angioedema of the feet
following walking or running19 and
less often food hypersensitivity.20 –23
The managing physician may require
the expertise of anallergist/clinical immunologist to evaluate unusual causes
of angioedema (see Annotation 8 for
other etiologies).
A history of angioedema alone may
suggest a rare disorder of C1esterase
inhibitor deficiency, which may be in-

VOLUME 85, DECEMBER, 2000

herited as a autosomal dominant or
acquired
angioedema
due
to
C1esterase inhibitor deficiency may
present as an acute episode of...