Dr. Gabor reports that IVIg-associated aseptic meningitis mandates a lumbar puncture and has a protracted course, requiring 9 to 14 days of hospitalization. I have a different view. We have reported [1, 2] that IVIg-associated aseptic meningitis is aseptic, not bacterial. Cultures of the cerebrospinal fluid in all six of our originally studied cases were negative [1]. In addition, no cases of bacterial meningitis have been reported; hence, I do not advocate the use of antibiotic prophylaxis.

For the treatment of chronic autoimmune neurologic diseases, repeated IVIg infusions are needed. In some patients, especially those with migraine [1], meningitis may develop after each IVIg infusion. Should we perform lumbar punctures after each episode? The temporal profile of IVIg-associated aseptic meningitis is predictable, characteristic, and short lived. Performing a lumbar puncture after each episode may not only be uninformative but may increase morbidity as a result of the additional risk for post-lumbar puncture headache and meningismus. The protracted hospitalization in Dr. Gabor's case might have been related to post-lumbar puncture complications. In our experience with more than 110 patients and 330 monthly IVIg infusions, the course of IVIg-associated aseptic meningitis was brief (no longer than 5 days; average, 2 to 3 days) and required only conservative care with narcotic analgesics and antiemetics. Having said that, one cannot exclude unusual circumstances that could shake confidence in even an expert clinical judgment. One such occurrence could be the suspicion of subarachnoid hemorrhage, which may have a clinical presentation identical to that of aseptic meningitis and has the remote potential to develop acutely in some patients with certain underlying conditions who are treated with IVIg. In such circumstances, computed tomography of the brain may be indicated.

Dr. Gabor also reports the absence of IVIg-associated aseptic meningitis in patients with lymphoproliferative diseases, paraproteinemia, or myeloma. This could have been a chance occurrence if the number of treated patients was small. We have observed IVIg-associated aseptic meningitis in 1 of 11 patients with IgMk paraproteinemia and demyelinating polyneuropathy [1, 3].

Catteau and coworkers describe two interesting skin reactions related to IVIg. We have also seen palmar pruritus and lichenoid keratosis in at least two patients. It remains to be determined whether these are allergic phenomena caused by the various components of IVIg or immunologic reactions between the infused IgG and the skin antigens recognized by the various auto-antibodies within IVIg. Skin biopsy with immunopathology may clarify the range and cause of these manifestations.