Immunotherapy Safety for the Primary Care ... - U.S. Coast Guard

S498 Lieberman et al
J ALLERGY CLIN IMMUNOL
MARCH 2005
TABLE II. Types of anaphylaxis and the differential
diagnosis of anaphylaxis and anaphylactoid reactions
Types of anaphylaxis and anaphylactoid reactions
Anaphylaxis (anaphylactoid reactions) to exogenous agents
Anaphylaxis and anaphylactoid reactions to physical factors
Exercise
Cold
Heat
Sunlight
Idiopathic anaphylaxis
Anaphylaxis and anaphylactoid reactions caused by the excess
endogenous production of histamine
Systemic mastocytosis
Urticaria pigmentosa
Basophilic leukemia
Acute promyelocytic leukemia with tretinoin treatment
Hydatid cyst
Vasodepressor (vasovagal) reactions
Other forms of shock
Hemorrhagic
Hypoglycemic
Cardiogenic
Endotoxic
Flushing syndromes
Carcinoid
Red man syndrome caused by vancomycin
Postmenopausal
Alcohol induced
Unrelated to drug ingestion
Related to drug ingestion
Medullary carcinoma thyroid
Autonomic epilepsy
Vasointestinal peptide and other vasoactive peptide–secreting
gastrointestinal tumors
Ingestant-related reactions mimicking anaphylaxis (restaurant
syndromes)
Monosodium glutamate
Sulfites
Scombroidosis
Nonorganic diseases
Panic attacks
Vocal cord dysfunction syndrome
Miscellaneous
C1 esterase deficiency syndromes (acquired and hereditary
angioedema)
Pheochromocytoma
Neurologic (seizure, stroke)
Capillary leak syndrome
5. The patient should be instructed to wear and/or carry
identification denoting his or her condition (eg, Medic
Alert jewelry). C
Performing the history
To interpret the history adequately, it is essential to
know the manifestations of anaphylaxis. These can best be
ascertained by a review of published series. 1-14 A
summary of the signs and symptoms as reported in these
series, totaling 1865 patients, is seen in Table I. These
series include patients with exercise-induced anaphylaxis,
patients with idiopathic anaphylaxis, patients of all age
ranges, and reviews of patients with anaphylaxis from
various causes. The most frequent manifestations of
anaphylaxis are cutaneous, occurring in more than 90%
of reported series. The absence of cutaneous symptoms
speaks against a diagnosis of anaphylaxis but does not rule
it out. Severe episodes characterized by rapid cardiovascular
collapse and shock can occur without cutaneous
manifestations. 15,16 Friends and/or family members present
during the event should be interviewed to better assess
the signs and symptoms of the reaction. Anaphylaxis can
present with unusual manifestations (eg, syncope without
any other sign or symptom). 17,18
The history and the record should include the time(s) of
the occurrence of the attack(s), any treatment required
during the attack(s), and the duration of the episode(s). A
detailed history of all potential causes should be obtained.
This includes a list of ingestants consumed before the
event, including both foods and drugs; any possible stings
or bites occurring before the event; whether the event
occurred during exercise; location of the event (eg, work
versus home); and whether the event was related to
exposure to heat or cold or sexual activity. The patient’s
atopic status should be noted because food-induced and
idiopathic anaphylaxis are more common in atopic than
nonatopic individuals. Also, in women the history should
include any relationship between the attack(s) and their
menstrual cycle. Return of symptoms after a remission
should be noted because this might indicate a late-phase
reaction, 6 which might require a prolonged period of
observation if subsequent events occur.
Differential diagnosis
The vast majority of patients presenting with a history
consistent with anaphylaxis will have experienced an
anaphylactic event. Nonetheless, it is important not
to immediately accept this diagnosis. The differential
diagnosis must be considered when the history is taken,
even in patients with a previous history of anaphylaxis.
Comprehensive differential diagnoses are seen in Table II.
Special attention in the differential diagnosis should
be given to vasodepressor (vasovagal) reactions. Characteristic
features of this reaction include hypotension,
pallor, weakness, nausea, vomiting, and diaphoresis.
Such reactions can often be distinguished from anaphylaxis
by a lack of characteristic cutaneous manifestations
(urticaria, angioedema, flush, and pruritus) and the
presence of bradycardia during the vasodepressor reaction
instead of the tachycardia usually seen with anaphylaxis.
However, it should be noted that bradycardia can occur
during anaphylaxis as well. 19 This is probably due to the
Bezold-Jarisch reflex, a cardioinhibitory reflex that has its
origin in sensory receptors in the inferoposterior wall of
the left ventricle. Unmyelinated vagal C fibers transmit the
reflex.
Flushing episodes can mimic anaphylactic events. As
noted, the history should include all of the drugs that the