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Acute Axonal Polyneuropathy Following Honey-Bee Sting: A Case Report

Journal of Child Neurology 2014, Vol. 29(5) 674-676 ª The Author(s) 2014 Reprints and permission: DOI: 10.1177/0883073813517262

Arushi Gahlot Saini, MD1, Naveen Sankhyan, MD, DM1, Renu Suthar, MD1, and Pratibha Singhi, MD1

Abstract Hymenoptera stings lead to a myriad of neurologic manifestations by the mechanism of immediate or delayed hypersensitivity reactions. The more common form of polyneuropathy associated with these stings is the acute inflammatory demyelinating type. We describe a 6-year-old girl, who developed progressive, symmetrical, ascending weakness within 3 days after a bee sting. Serial nerve conduction studies confirmed acute, motor-predominant axonal polyneuropathy. Use of intravenous immunoglobulin induced halt of progression, prompt stabilization and a gradual recovery. This case highlights that even a single honey-bee sting can result in acute-onset axonal variety of polyneuropathy in children. Keywords Guillain-Barre` syndrome, toxic neuropathy, hymenoptera, envenomation, AMAN Received July 22, 2013. Received revised September 02, 2013; November 05, 2013. Accepted for publication November 25, 2013.

Hymenoptera stings can lead to a myriad of neurologic manifestations in children, such as encephalitis, encephaloradiculopathy, stroke, neuromuscular paralysis, acute inflammatory polyradiculopathy, and optic neuropathy. The more common form of polyneuropathy associated with these stings is of the demyelinating type.1-3 The occurrence of acute, motor axonal polyneuropathy (AMAN) following a single honey-bee sting in children is rarely reported in the literature.4,5 We describe here this unusual presentation in a 6-year-old girl.

Case Report A previously well, 6-year-old-girl was admitted with progressive inability to bear weight on her legs and difficulty in getting up from lying down position for the last 1 week. The symptoms had followed a honey-bee sting on the inner side of left thigh. There was local pain and swelling at the sting site for the next 2 days. This was followed by diffuse, continuous pain over thighs and calves. A progressive, ascending weakness of the lower extremities ensued 3 days after the bee sting. Within a day, it was followed by inability to get up or turn in the bed unsupported. There was no weakness or pain in the upper limbs. There was no history of any fever, rash, viral illness, recent vaccination or previous insect bite. The personal and family history was unremarkable. Examination revealed an alert, cooperative child with normal anthropometry and vital signs. The site of sting at the medial left thigh showed localized erythema and induration with no stinger in-situ. Neurologic examination showed normal higher

mental functions and normal cranial nerves, including fundi. In the lower limbs, there was mild muscle tenderness, hypotonia, and weakness. Muscle strength was 3/5 in the knee and hip, flexors and extensors, whereas it was 2/5 at the ankle, plantar and dorsi-flexors. Muscle stretch reflexes were absent at ankles, and diminished at knees. Upper limb strength and reflexes were normal. Superficial reflexes were normal and plantar response was flexor. She was unable to sit or stand independently. Sensory testing revealed no abnormality. There were no cerebellar or meningeal signs. Examination of other systems did not reveal any abnormality. Laboratory investigations revealed normal urinary analysis, complete blood count, serum electrolytes, and renal and liver function tests. Cerebrospinal fluid protein was 110 mg/dL, glucose was 49 mg/dL (blood glucose 90 mg/dL), there were no cells, and Gram stain and culture were negative. Serum creatine kinase was 40 IU (30-100 IU). Nerve conduction studies suggested a pure motor axonopathy in the upper limbs and a severe, pure motor polyneuropathy of uncharacterized nature in the


Unit of Pediatric Neurology and Neurodevelopment, Department of Pediatrics, Postgraduate Institute of Medical Education and Research, Chandigarh, India

Corresponding Author: Pratibha Singhi, MD, Chief Pediatric Neurology and Neurodevelopment, Advanced Pediatrics Centre, Department of Pediatrics, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India. Email: [email protected]

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Saini et al


Table 1. Electrophysiological Nerve Studies at Presentation and at the 3- and 20-Week Follow-Up After Intravenous Immunoglobulin. Nerve

Distal Distal latency (ms) amplitudes (mv)

Motor nerves Tibial Presentation Unexcitable Week 3 Unexcitable Week 20 3.7 Common peroneal Presentation Unexcitable Week 3 Unexcitable Week 20 Unexcitable Median Presentation 2.2 Week 3 2.8 Week 20 3.02 Ulnar Presentation 3 Week 3 1.8 Week 20 1.88 Sensory nerves Sural Presentation 1.6 Week 3 1.9 Week 20 2.40 Median Presentation 1.9 Week 3 1.8 Week 20 2.24

Conduction velocity (m/s)



2.8 4.2 6.1

55 54 55.5

0.8 1.4 2.8

62 60 57.3

19 8 20.3

56 47 45.9

24 18 10.3

43 56 49.1

lower limbs. Sensory conductions were normal in all nerves. The overall pattern was consistent with a diagnosis of acute motor axonal neuropathy (Table 1). She was treated with intravenous immunoglobulin (2 g/kg over 2 days). Subsequent to this, there was halt in the progression of weakness and gradual improvement in her symptoms. After 3 weeks’ follow-up, the child was standing without support and was able to walk >10 m with 1 hand held. Nerve conductions at this time showed an increase in motor nerve amplitudes in upper limb nerves with no change in lower limb findings. At 20 weeks’ follow-up, she has not attained premorbid functional status. She is able to walk unassisted but unable to run. She has mild bilateral foot drop and difficulty in climbing stairs. Muscle strength is 3/5 in the hip extensors and 2/5 in the ankle dorsiflexors. Muscle strength in the upper limb muscle groups is normal. Muscle stretch reflexes are normally elicitable at ankles and knees. She is under regular physiotherapy and stretching exercises.

Discussion The Hymenoptera order of insects includes 3 medically important groups: Apoidea (bees), Vespoidea (wasps, hornets, and yellow jackets), and Formicidae (ants). Among these, acute neuropathy has been commonly reported following wasp and bee stings. The wasp sting is commonly associated with pure demyelinating motor polyneuropathy with secondary axonal

changes due to hypersensitivity reaction.1,6 Our patient developed pain and weakness 3 days after a bee bite. This pattern of acute motor axonal neuropathy following a single bee sting in children has been scarcely reported. Yilmaz et al reported axonal pattern in a 4-year-old girl wherein a combination of viral upper respiratory tract infection, bee sting, and the finding of herpes simplex virus type-2 seropositivity accelerated the postulated immunologic mechanism.5 Minor conduction abnormalities in sensory nerves have been reported in up to 12% of acute motor axonal neuropathy patients, blurring the dichotomy between acute motor axonal neuropathy and acute motor sensory axonal neuropathy.7 Nearly 64% of patients with baseline normal sensory conductions could show significant changes in sensory amplitudes with gradual recovery after 4 to 5 weeks in acute motor axonal neuropathy patients.8 Likewise, mild sensory involvement cannot be ruled out in the index patient as both the sural and median sensory amplitudes were normal at the time of initial diagnosis and declined in the follow-up visits with gradual recovery at 5 weeks. However, as the sensory amplitudes were not reduced to

Acute axonal polyneuropathy following honey-bee sting: a case report.

Hymenoptera stings lead to a myriad of neurologic manifestations by the mechanism of immediate or delayed hypersensitivity reactions. The more common ...
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