IgE response to Anisakis compared to seafood

out a desensitization protocol (Table 1). Mesalazine solutions were prepared by the pharmacy at two concentrations (10 and 100 mg/ml) for easy dispensing. As the usual initial adult dose of mesalazine is 3 g daily in divided doses, it was the highest dose tested. The patient had no recurrence of the fever either during or after the mesalazine desensitization schedule (his current mesalazine daily regimen is 500 mg/8 h). Drug fever is pyrexia that develops coincidentally with the administration of a drug and disappears with discontinuation, for which no other cause can be established by a careful examination and laboratory investigation. The pathogenesis of fever by drugs remains unknown in most cases. To our knowledge, this is the ®rst case described in the literature of a patient with fever induced by mesalazine who was successfully desensitized. Although there are some cases reported of mesalazine causing fever associated with other symptoms ± hypotension (1); vasculitic rash, arthritis, pericarditis, and pericardial effusion (2); and watery stools and vomiting (3) ± in our case, all symptoms could be explained by fever alone. Tolerance induction through exposure to graded doses has been proposed as a safe means to suppress the allergic response, although the mechanism by which tolerance is induced is unclear. Regarding our results, we think that desensitization is an important therapeutic strategy in cases similar to ours. Although Nakajima et al. suggest that mesalazine is effective for the treatment of patients who are intolerant of sulfasalazine (4), other authors report allergic reactions to 5-ASA in patients who had previously experienced similar reactions to sulfasalazine, a fact which suggests that 5-ASA is responsible for these reactions rather than sulfapyridine (3, 5, 6). In conclusion, mesalazine treatment can induce fever in some patients, but desensitization is possible.