INTRODUCTION:Peripheral eosinophilia can be caused by autoimmune diseases, airway diseases, malignancy, and parasitic infection. Excluding the latter prior to treatment with immunosuppressive agents is crucial, as the consequences of compromising the immune system in the setting of parasitic infection can be devastating. Here, we report a case of disseminated Strongyloides steracolis infection complicated by an exacerbation of porphyria that resulted in severe neurologic dysfunction and respiratory failure.
CASE PRESENTATION:A 61 year old male with a history of acute intermittent porphyria and alcoholism was evaluated in the community for peripheral eosinophilia. Approximately one month after initiating treatment with high dose corticosteroids for this condition, he was admitted to a local hospital with progressive mental status changes and a urinary tract infection (UTI). Despite treatment for his UTI, his mentation continued to decline and he subsequently developed respiratory failure. Evaluation included chest computed tomography (CT) which revealed bilateral nodular infiltrates and lumbar puncture which showed no evidence of infection. The patient was then transferred to our institution for further evaluation. Physical examination revealed a cachectic male; he was mechanically ventilated with stable vital signs. Pulmonary examination demonstrated bilateral coarse breath sounds with fine rales at the right lung base. Skin examination revealed a non-blanching petechial rash on his chest, abdomen and lower extremities. Neurologic exam was notable for absence of gag and cough reflexes, diminished peripheral reflexes, and flaccid extremities. Head CT demonstrated brain atrophy; repeat chest CT was notable for bilateral basilar nodular opacities (figure 1). Fiberoptic bronchoscopy revealed purulent green secretions on airway examination. Bronchoalveolar lavage microscopy demonstrated the presence of Strongyloides steracolis (figure 2A.) Biopsy of the skin also revealed strongyloides. Urine chemistries confirmed a porphyria flare. Despite hemin administration and appropriate antibacterial therapy, the patient’s mental status did not improve. After a protracted hospital course, the patient’s family elected to discontinue mechanical support; the patient died shortly thereafter. Post-mortem examination revealed disseminated strongyloides involving the lung (Figure 2B), GI tract, pancreas, kidneys, pericardium, and skin but sparing the central nervous system. Neuropathology showed evidence of a demyelinating neuropathy and changes in the brain consistent with encephalitis.
DISCUSSIONS:In this report, we present a patient with acute intermittent porphyria and peripheral eosinophilia treated with corticosteroids. It is likely that the patient’s eosinophilia was due to infection with Strongyloides steracolis, a nematode parasite endemic to the southeastern United States. Strongyloides infection is usually indolent and relatively asymptomatic. However, in the presence of immunosuppression, smoldering chronic Strongyloides can blaze into a disseminated infection. Failure to recognize this syndrome can easily lead to delay in treatment with appropriate antihelminthic agents.In this case, the delay in diagnosing strongyloidiasis was of profound significance due to the concomitant presence of acute intermittent porphyria. Attacks of porphyria can be precipitated by any condition that upregulates aminolevulinic acid synthase (the rate limiting step in heme biosynthesis), including physiologic stress associated with active infection. The symptoms associated with porphyria flares are thought to be mediated by buildup of neurotoxic substrates; in extreme cases, profound encephalopathy and respiratory paralysis can occur. For this patient, the presence of ongoing infection led to an unabated flare of porphyria which then resulted in progressive respiratory failure and profound encephalopathy, with severe neuropathy found on post-mortem examination.
CONCLUSION:Peripheral eosinophilia can be found in a number of different diseases and syndromes. A comprehensive workup, including evaluation for the presence of parasites, should be undertaken prior to initiating a patient on immunosuppression. As in this case, the administration of corticosteroids to a patient with unrecognized Strongyloides infection can have devastating consequences.
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