17
3.0 Recognizing and Treating HAE
3.12 Typical Age at Symptom Onset
As an inherited condition, individuals with HAE have the
genotype for life. However, the expression of this gene
as acute attacks of HAE varies considerably, even among
related individuals. In fact, Agostoni et al noted that about
5% of asymptomatic adult HAE patients were identified as
having
SERPING1
mutations solely as a result of a diagnosis
in symptomatic HAE offspring.
5
However, symptom-free
HAE is the exception rather than the rule.
30
For most individuals, acute attacks begin to occur in the
first or second decade of life; perinatal episodes occur
rarely.
5,10,23,30
Initial presentation in later adulthood is also
atypical.
31
3.11 Characterizing HAE Symptoms
As stated earlier, the symptoms of acute attacks of
HAE are caused by increased capillary permeability and
the extravasation of fluid into the deeper cutaneous
or submucosal layers of tissue. Cutaneous attacks of
HAE typically present as episodes of nonpitting, non-
erythematous swelling with ill-defined margins.
5,8
The
characteristic of HAE is the absence of itching and redness
in these attacks.
5,8
In the rare instances in which urticaria
may occur, it is short-lived.
5
The swelling attacks in the
submucosal layers of the GI tract can result in moderate to
severe abdominal pain, nausea, vomiting, or diarrhea.
5,8,11
Chapter 3 Highlights
•
Individuals with HAE have the genetic trait
for life, but the expression of that gene as
symptoms of angioedema can vary widely
in terms of age at symptom onset, frequency
of attacks, anatomical sites of edema, and
precipitating events.
•
These variations in phenotype occur both
intraindividually (at different life stages)
and among individuals, even with the same
genetic mutation.
•
Diagnostic criteria include serum screening
of C4 and C1-INH proteins, and assessment
of C1-INH function.
•
In some patients, prodromal symptoms
are the first sign of an acute attack of
angioedema.
•
C1-INH replacement therapy is an inter-
nationally recommended first-line treat-
ment for attacks of HAE.
•
HAE attacks can impact quality of life,
resulting in absenteeism, hospitalization, pain,
suffering, nausea, vomiting, and anxiety;
HAE can also shorten life expectancy as a
result of asphyxiation or hypovolemic shock
that can occur in some attacks.
3.1 Recognizing the Clinical Presentation of HAE
HAE
