Hymenoptera sting complicated by pseudotumor cerebri in a 9-year-old boy

To the Editor:

The insect order Hymenoptera consists of Vespidae (hornets, wasps, and yellow jackets), Apidae (honey bees and bumble bees), and Formicidae (ants) (1). We presented a case of pseudotumor cerebri (PC) following a single wasp sting in a 9-year-old boy.

A 9-year-old boy presented with a 2-day history of severe headache associated with recurrent vomiting and high-grade fever following a single wasp sting on the left side of his neck. The sting was associated with marked local swelling and cervical lymphadenopathy. He had no history of recent illness, head trauma, or intake of other medications. He was being treated with ibuprofen and oral amoxicillin-clavulanate. The pupils were bilaterally symmetrical with normal reaction to light and accommodation. The examination of the optic fundi revealed papilledema stage 2 (early papilledema as per Frisen scale). The other cranial nerves and the remainder of the neurological examination were normal. Review of the other major systems was non-contributory. Serum glucose, electrolytes, renal function tests, and complete blood cell count were normal. The cranial magnetic resonance (MR) and MR venography revealed no abnormalities. The lumbar puncture revealed an opening pressure of 412 mm of water and clear cerebro-spinal fluid (CSF) with normal cell count, protein, and glucose content. He was treated with oral furosemide and acetazolamide, to which he responded favorably. The culture of the CSF was sterile. A diagnosis of PC secondary to Hymenoptera sting was made. He was discharged on the 10th post-admission day, having made full neurological recovery. Clinical and CSF examination results at 6 weeks were normal.

Neurological complications following Hymenoptera sting are rare. Cerebral infarction, the most commonly described, may lead to seizure, hemiparesis, aphasia, apraxia, dysarthria, ataxia, visual and speech deficits, cranial neuropathies, cerebellar symptoms, and coma (2).

Other reported CNS complications include optic neuritis, myasthenia gravis, acute inflammatory polyradiculopathy, encephalomyeloradiculoneuritis (3), parkinsonian syndrome (4), encephalopathy, limb numbness, and trigeminal neuralgia (5). An instance of combined cerebral infarction leading to stroke and ischemic optic neuropathy following multiple bee stings is also reported (2).

To our knowledge, there is a single report of PC occurring as an isolated complication of wasp sting. Sorabjee et al. (6) described a 42-year-old woman who developed fever, severe headache, and toxemia following a single wasp sting over her right eyelid. The diagnosis was made on the basis of normal lumbar puncture study, papilledema, and normal MR study of the brain with unremarkable cranial MR venography.

The boy had no history of previous wasp or bee stings. Furthermore, other risk factors for the development of PC, especially infections and drugs, were excluded. The temporal course of events implicates the wasp sting for the symptoms in the boy.

Sorabjee et al. (6) hypothesized that the proximity of the sting to the brain might have been a factor in causing the elevated CSF pressures as a result of intracranial inflammation due to the potentially neurotoxic wasp venom. The boy had the sting on his neck, which may support the explanation put forward.

In conclusion, whereas severe neurological manifestations remain well documented, milder neurological manifestations like PC may be seen in children following wasp stings on the head or neck. Monitoring of such children, especially with minor neurological symptoms, is indicated.