to Arthropod Bites and Stings - Entomological Society of America

This species does not have a sting; nevertheless, it caused an anaphylactic
reaction through its bite (Schmid-Grendelmeier 1997). In addition
to biting, ants in this genus spray formic acid that is produced
in the venom gland along with other compounds.
Hemiptera. In comparison to the stinging Hymenoptera, biting
insects cause far fewer allergic reactions. By far the most frequent in
the U.S. are allergic reactions to bites from kissing bugs (Triatoma and
Paratriatoma spp.). For example, in one small community in Santa
Barbara County, California, about 7% of the population has been
sensitized to bites of the western conenose bug, Triatoma protracta
(Marshall et al. 1986). Another species, T. rubida, is more common
in central and southern Arizona and is particularly a problem in the
foothills of Tucson, where most of the allergic reactions are reported
for this species (Pinnas et al. 1986). Interestingly, there is little to
no antigenic cross-reactivity between these two species (Pinnas et
al. 1986).
There are 14 other species of Triatoma that are found throughout
the lower two-thirds of the U.S. (Vetter 2001). All are blood-suckers
that normally parasitize wood rats, opossums, raccoons, and armadillos
(Vetter 2001). During the spring and early summer dispersal,
T. rubida and T. protracta sometimes enter homes and feed on the
occupants as in the following case (Klotz et al. 2006):
A 45-year old woman had four severe reactions to an insect bite.
She found the insect in bed each time and from the description, it fit
the picture of a kissing bug. She never felt the bite, but noticed her
heart rate increasing and felt hot. One of the authors (JP) attributes
the rapid heartbeat to the adrenal gland’s response to elevated histamine
levels, which sometimes can “self-treat” and thereby result in
non-life-threatening reactions. In two instances, she lost consciousness
and during one episode, she had a seizure. Her son captured a
specimen from her bed that was identified as T. rubida.
Although bedbugs are an emerging problem in the U.S., anaphylactic
reactions to their bites, are rare (Parsons 1955).
Diptera. Blood-sucking flies, including horse flies (Tabanus), deer
flies (Chrysops) (Freye and Litwin 1996; Hemmer et al. 1998; Hrabak
and Dice 2003; Wilbur and Evans 1975), black flies (Simuliidae)
(Hoffman 1987), tsetse flies (Glossina) (Stevens et al. 1996), louse
flies (Hippoboscidae) (Vidal et al. 2007), and mosquitoes (Culicidae)
(McCormack et al. 1995), have caused anaphylactic reactions.
Considering the number of people bitten by mosquitoes, there are
surprisingly few reports of anaphylactic reactions, but large local
reactions are not uncommon (Engler 2001).
Anaphylactic-like reactions to punkies (Culicoides) (Hoffman
1987), snipe flies (Symphoromyia) (Turner 1979), and stiletto flies
(Therevidae) (Smith 1979) have been reported. The larvae of punkies
are aquatic or semiaquatic and the adults do not travel far from
where the larvae live (Triplehorn and Johnson 2005). Most snipe
flies do not bite, but several species of Symphoromyia do bite and
are common in western mountain and coastal regions of the U.S.
(Triplehorn and Johnson 2005). In the case of the stiletto fly, it was
the larva that bit the victim. The adult flies are uncommon but the
predaceous larvae can be found in sand or decaying wood (Triplehorn
and Johnson 2005).
Lepidoptera. There are several families of Lepidoptera with caterpillars
possessing stinging hairs, some with venoms that can cause
anaphylactic reactions in susceptible individuals. These include the
pine processionary caterpillar, Thaumetopoea pityocampa, so called
because of the long lines they form, sometimes with hundreds of individuals
following a lead caterpillar to and from the nest (Sbordoni
and Forestiero 1985). Their hairs, which can be airborne, penetrate
the skin and release a toxic substance (Vega et al. 1999, 2000), or may
be inhaled or ingested. The most common reaction is a cutaneous
lesion; however, in northwestern Spain, as many as 40% of patients
diagnosed with occupational urticaria suffered anaphylactic reactions
(Vega et al. 2004). There are also reports of systemic reactions
in children (Shkalim et al. 2008).
Anthelid larvae and frequently their cocoons are protected by
stinging hairs. There are about 100 species native to Australia and
New Guinea, and the larger members belong to the genus Chelepteryx
(Sbordoni and Forestiero 1985). The caterpillar of the whitestemmed
gum moth (Chelepteryx collesi) incorporates urticating
hairs into its cocoon. The hairs, which point out, readily penetrate
human skin and have caused anaphylactic-like reactions (Mulvaney
et al. 1998).
In Texas from 1955 to 1959, there were 54 reported cases of
stings by caterpillars: 47 were localized reactions, and the others
anaphylactic-like reactions (Micks 1960). The caterpillar was identified
in 43 of these cases and determined to be Megalopyge opercularis.
Commonly known as puss caterpillars, they are covered with soft
brown hairs with poison spines beneath that can penetrate the skin,
causing severe reactions (Borror et al. 1976).
Arachnids
Acari. There are several reports of anaphylactic reactions to bites
from hard ticks (Ixodidae), most notably the Australian paralysis tick,
Ixodes holocyclus (Gauci et al. 1989). Ticks caused approximately
0.7% of the reported allergic reactions to arthropod stings and bites
in Queensland, Australia (Solley 1990). In other parts of the world,
there are fewer reports: a 73-year old man who suffered recurrent
anaphylaxis due to bites from Ixodes pacificus (Van Wye et al. 1991a,
b), a widely distributed species in western North America; and cases
in western Europe involving Ixodes ricinus (Moneret-Vautrin et al.
1998) and Rhiphicephalus spp. (Acero et al. 2003; Valls et al. 2007).
The pigeon tick, Argus reflexus, is a much more common cause
of anaphylactic reactions in Europe (Hilger et al. 2005; Rolla et al.
2004). It is a soft tick (Argasidae) that is a temporary parasite of wild
and domesticated pigeons. When its normal host is absent, the ticks
may migrate into households and bite the human occupants, some
of whom may be allergic.
Scorpions. Fatalities due to scorpion stings are by some estimates
as high as 50,000 deaths per year worldwide (White 1995). These
are mostly due to toxic reactions. Even in certain parts of the U.S.,
scorpion stings are common. For example, in Arizona (excluding the
greater Phoenix area), there were 4,655 scorpion stings reported
over a two-year period from 2002-2004 (Klotz et al. 2005a).
Fatalities due to scorpion stings are rare in the U.S., but five deaths
were recorded from 1950-1954, one of which was an anaphylactic-like
reaction (Parrish 1959). In 2001 in Arizona, a woman died
from an anaphylactic-like reaction to a sting by the bark scorpion, C.
exilacauda (Boyer et al. 2001). It is the deadliest species in the U.S.
and is mainly found in Arizona (Curry et al. 1984). IgE-mediated
anaphylaxis to its sting has also been reported (Chase et al. 2002).
Although anaphylactic reactions to their stings are rare, the venom
of the common striped scorpion, Centruroides vittatus, is reportedly
cross-reactive with imported fire ants, S. invicta (Nugent et al. 2004).
The geographic distribution of striped scorpions and imported fire
ants overlap, possibly placing many more people at risk for allergic
reactions.
American Entomologist • Volume 55, Number 3 137