Eosinophilic Meningitis in a Previously Healthy 13-year-old Child

A previously healthy 13-year-old male developed acute onset of a bitemporal headache. The headache persisted, and 2 weeks later, he was diagnosed with sinusitis and was given amoxicillin. On illness day 17, he experienced worsening headache, slurred speech, transient left facial droop, right hand numbness and dizziness. At a local emergency department (ED), magnetic resonance imaging of the brain showed no significant abnormalities, although images were obscured by artifact from his orthodontic hardware. He was discharged without a specific diagnosis after his neurologic symptoms had resolved. On illness day 19, the patient had return of hand tingling and slurred speech and presented to the Children’s Hospital Colorado ED. He was diagnosed with an atypical migraine and was treated with ketorolac, diphenhydramine and prochlorperazine. His symptoms improved, and he was discharged. On illness day 20, the patient experienced severe right eye pain and recurrence of his headache. He returned to his local ED and was hospitalized after minimal clinical improvement with treatment for migraine. At that time, his Romberg sign was abnormal, he was ataxic and he had diplopia. On illness day 22, he underwent a lumbar puncture because of concern of pseudotumor cerebri. The cerebral spinal fluid (CSF) showed white blood cell (WBC) count of 763/mm3 (with a differential of 80% lymphocytes, 15% monocytes and 5% eosinophils), red blood cell count of 2/mm3, protein of 49 mg/dL and glucose of 54 mg/dL. Intravenous acyclovir was started but was discontinued when polymerase chain reaction (PCR) assay of the CSF for herpes simplex virus returned negative. Bacterial and fungal cultures of the CSF were negative. He was discharged home after a 3-day hospitalization. Over the next several weeks, he remained stable but continued to have intermittent headaches and ongoing diplopia. Then, 47 days after initial onset of illness, the patient developed severe right eye pain and photophobia and returned to the local ED. Repeat lumbar puncture showed an opening pressure of 44 cm H2O, WBC of 347/mm3 (with a differential of 53% lymphocytes, 26% monocytes and 21% eosinophils), red blood cell of 3/mm3, protein of 127 of mg/dL and glucose of 35 mg/dL. He was subsequently transferred to Children’s Hospital Colorado. On admission, the patient was afebrile and had normal vital signs. Physical examination showed papilledema with splinter hemorrhages, left esotropia with subjective diplopia and no signs of meningismus. Complete blood count showed WBC of 9100/mm3 (with differential of 44% neutrophils, 33% lymphocytes, 11% monocytes and 12% eosinophils), hemoglobin of 16.1 g/dL, hematocrit of 47.1% and platelet count of 320,000/mm3. Repeat lumbar puncture on day 50 of illness showed an opening pressure of 34–35 cm H2O, WBC of 273/mm3 (with a differential of 46% lymphocytes, 46% eosinophils, 5% monocytes and 3% macrophages), red blood cell of 32/mm3, protein of 107 mg/dL and glucose of 38 mg/dL. A brain magnetic resonance imaging performed after removal of the patient’s braces was normal. Additional blood testing was negative, including EBV PCR, Bartonella henselae IgG/IgM, Bartonella quintana IgG/IgM, Blastomyces antibody, Coccidioides IgG/IgM, Histoplasma antibody, HIV 1/2 antibodies, Cryptococcus antigen, Toxocara antibody and Toxoplasma IgG/IgM. CSF acid-fast bacillus stain, cryptococcal antigen, and mycobacterial, fungal, aerobic and anaerobic cultures were also negative. Upon further questioning, the patient reported that he and his family had traveled to their vacation home in Kauai, Hawaii, for the 2 weeks directly preceding the onset of symptoms. They had not stopped on any other Hawaiian island. During the trip, the family had found a dead rat in their hot tub, although the patient had not been in it. They had consumed organic lettuce from a local vendor and fresh produce from their herb garden. The patient denied exposure to seafood, mollusks or other exotic cuisine. The family had stopped in Los Angeles on their return trip home but had not ventured outside of the city. The patient denied any other travel, animal contact or known insect bites. The patient’s exposure history prompted additional testing of the CSF, which confirmed the etiology of his eosinophilic meningitis. For denouement see p. 198