Although well-controlled studies of clinical manifestations of H
nana infections are scarce, most H nana infections
are most probably asymptomatic or unnoticed.3 Symptoms
reported from several series of H nana infections
are anorexia or increased appetite, nausea, vomiting, pains in the
extremities, dizziness, and headache. Other reported symptoms are
abdominal pain, diarrhea, restlessness, restless sleep, irritability,
and nasal and anal pruritus. There are conflicting reports about
correlation between the numbers of parasites and the presence of
symptoms. Although a mild eosinophilia is a common finding in H
nana infections, it is often absent. Rarely, H
diminuta may be diagnosed, mostly in asymptomatic cases
in stool surveys.4 The few reported cases do not
allow examination of differences in clinical manifestations or response to
treatment between H nana and H
Routine fecal examinations using concentration techniques for
ova and parasites should reveal eggs of H nana (Fig. 339-1) or more rarely H diminuta (Fig. 339-2). However, a single examination may
not be adequate to rule out infection. Proglottids are rarely found
in stools since they disintegrate after breaking from the tapeworm.
ELISA tests for serum antibodies to H nana have
been used in research but are of no clinical use.5
Praziquantel is the drug of choice for the treatment of hymenolepiasis.
It is administered in a single dose of 25 mg/kg, although
a second dose 10 to 15 days later seems to increase its efficacy.
Patients should be informed that the drug is considered investigational
by the FDA if used for this purpose. Niclosamide is also effective
but is no longer available in the United States. Nitazoxanide can
be used as an alternative with slightly lower efficacy.3 Because
it is common for several individuals within a household to be infected,
fecal examinations should be performed on all household members
before initiating treatment. Posttreatment fecal examinations should
be done at least 1 month after treatment.