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| Journal of the New Zealand Medical Association,
31-March-2006, Vol 119 No 1231
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Cutaneous larva migrans (hookworm) acquired in Christchurch,
New Zealand
Laurens Manning, Stephen Chambers, Graeme Paltridge, Paul
Maurice
Case reportAn 80-year-old woman presented to the outpatient clinic with
a 4-month history of an itchy migrating lesion on the skin of her right buttock.
Five months prior to presentation, she noticed an intensely pruritic lesion on
her buttock. This moved superiorly over the next 2 weeks before disappearing
spontaneously. A similar lesion appeared 3 weeks later. There was no response to
topical steroids or antifungals and 3 months later she was seen in our clinic
with ongoing symptoms. The patient kept no pets of her own. She had not
travelled overseas for more than 10 years, nor had she travelled to the North
Island recently. There were no serious coexisting chronic illnesses. She was
systemically well.
Examination revealed a linear, serpiginous lesion on the
upper right buttock. The terminal portion of the lesion was marked by a raised
3–4 mm vesicle (Figure 1).
Figure 1. Serpiginous lesion of cutaneous larva migrans
(hookworm) on the buttock
 The patient was a keen gardener and had moved into a
residence in suburban Christchurch 9 months previously. The house had a
substantial vegetable garden that previous owners had covered with pea straw.
Since moving into the house she had spent considerable time in the garden.
Whilst kneeling on a garden cushion she would regularly rock back so that her
buttocks would rest on her shoes or the ground.
A diagnosis of cutaneous larva migrans (CLM) was made.
Strongyloides stercoralis and
Toxocara canis serology was negative.
There was no blood eosinophilia. The lesion was biopsied close to the terminal
portion of the serpiginous lesion and she was given a course of oral
albendazole, 400 mg daily for 3 days. The patient reported complete resolution
of her symptoms and her lesion was not present 2 weeks later.
Microscopy of the skin biopsy (Figure
2) revealed a cross-section and longitudinal section of a larva in the
epidermis. This was thought to be a single coiled larva. There was dermal oedema
and an inflammatory infiltrate consisting mainly of lymphocytes and eosinophils.
The parasite measured 34 by 20 microns in cross section and
93 by 22 microns in longitudinal section. The cross section of the larva showed
an intestine with a lumen, distinguishing it from infectious third-stage
Strongyloides larvae that do not have
an intestine. The longitudinal section revealed two alae. These are longitudinal
ridges seen on the lateral aspect of the larva. The presence of double alae
rather than a single ala excludes
Toxocara as a cause for the lesion (G
Paltridge, personal communication with MD Little, 2005).
The most likely pathologic diagnosis was the larva of an
animal hookworm, but further speciation was not possible.
DiscussionCutaneous larva migrans is caused by the third-stage larva
of an animal hookworm that penetrates the epidermis after maturation in the
soil. CLM usually presents in returning travellers from tropical and subtropical
areas, particularly Africa, South East Asia, South America, the Caribbean, and
Florida.1 However CLM can be acquired in more temperate climates where the soil
and weather conditions are usually less favourable for larval survival and
development.2 Indeed, cases and outbreaks have been described in Italy,1
England,3 Scotland,4 and Germany.5
In New Zealand (NZ), home-grown acquisition of CLM is rarely
reported. Two cases of clinically diagnosed CLM in young children have been
described in the northern town of Kaitaia.6 To our knowledge, no cases have been
previously described in the cooler southern parts of the country.
Our patient acquired her infection in Christchurch and we
assume there were very specific local factors to encourage the presence and
survival of hookworm larvae. The pea straw mulch may have provided conditions
suitable to the maturation of third-stage larvae, particularly if roaming dogs
had defecated in this area. Whatever the origin of the larva, the patient had
significant skin-to-soil exposure in her garden to account for the acquisition
of CLM.
The exact causative organism remains uncertain as
microscopic identification of hookworm larvae is difficult. There is limited
literature regarding the prevalence of animal hookworms in NZ.
Ancylostoma braziliense has not been
identified in NZ dogs. Ancylostoma caninum
was first identified in NZ dogs in 1976,7 but is only rarely identified
in the faeces of dogs in northern areas.
Uncinaria stenocephala is a relatively
common infection of dogs in NZ especially where moist conditions around kennels
encourage transmission. Infection of cats has not been reported in NZ.8
Whilst not life-threatening, CLM causes considerable
distress and medical practitioners should be aware that the condition can
occasionally be acquired in NZ.
Author information:
Laurens Manning, Infectious Diseases Registrar, Chrsitchurch Hospital;
Stephen Chambers, Infectious Disease Physician, Christchurch Hospital; Graeme
Paltridge, Section Head, Bacteriology and Parasitology Laboratory, Canterbury
Health Laboratories; Paul Maurice, Dermatologist, Christchurch Hospital;
Christchurch
Acknowledgment: We
gratefully acknowledge Dr M Dale Little (Emeritus Professor, Department of
Tropical Medicine, Tulane University, New Orleans, USA) for assistance with
hookworm larva identification.
Correspondence: Dr
Laurens Manning, Infectious Diseases Registrar, Christchurch Hospital, Private
Bag 4710, Christchurch. Fax: (03) 364 0952; email: laurens.manning@cdhb.govt.nz
References:
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