Pulmonary Hypertension in Patients With Eosinophilia-Myalgia Syndrome or Toxic Oil Syndrome: The authors reply

Abstract

We thank Dr. Cheng for his interest in our editorial on 3-(phenylamino)alanine and appreciate his comments on pulmonary hypertension in people with eosinophilia-myalgia syndrome (EMS) or toxic oil syndrome (TOS). Although pulmonary symptoms were frequently the reason people sought treatment for TOS early during the epidemic, long-term pulmonary complications have not been as common as acute pulmonary symptoms. In one case series,1Abaitua Borda I Posada de la Paz M Clinical findings.WHO Reg Publ Eur Ser. 1992; 42: 27-38PubMed Google Scholar researchers found that during the acute phase of TOS, more than 72% of the 914 affected persons had clinical signs of pulmonary edema, whereas 2 months after onset of TOS, only 3.1% of the patients had signs and symptoms compatible with pulmonary hypertension. During the chronic phase, the percentage of persons with signs and symptoms of pulmonary hypertension increased to 10%.1Abaitua Borda I Posada de la Paz M Clinical findings.WHO Reg Publ Eur Ser. 1992; 42: 27-38PubMed Google Scholar Pulmonary hypertension was documented by measurements of pulmonary arterial pressure in only a few patients, however; therefore, the percentages previously cited reflect predominantly the results of clinical examinations and noninvasive tests.1Abaitua Borda I Posada de la Paz M Clinical findings.WHO Reg Publ Eur Ser. 1992; 42: 27-38PubMed Google Scholar A recent analysis of the morbidity data from the TOS patient registry showed that the cumulative rate of pulmonary hypertension in this cohort was 8.2% from 1981 to 1992 (Posada M. Personal communication [unpublished data from Fondo de Investigaciones Sanitarias Scientific Committee for the Toxic Oil Syndrome]. Madrid, 1993). In contrast to research on TOS, research on EMS includes only a few large case series, and one should be cautious in generalizing from the reported prevalence of specific symptoms in small case series. The patients in the case series reported by Tazelaar and colleagues2Tazelaar HD Myers JL Drage CW King Jr, TE Aguayo S Colby TV Pulmonary disease associated with L-tryptophan-induced eosinophilic myalgia syndrome: clinical and pathologic features.Chest. 1990; 97: 1032-1036Crossref PubMed Scopus (67) Google Scholar were specifically selected for study because of their pulmonary complications; thus, the high rate of pulmonary hypertension in this group is hardly surprising. In another case series, researchers reported only one case of pulmonary hypertension in 20 patients.3Martin RW Duffy J Engel AG Lie JT Bowles CA Moyer TP et al.The clinical spectrum of the eosinophilia-myalgia syndrome associated with l-tryptophan ingestion.Ann Intern Med. 1990; 113: 124-134Crossref PubMed Scopus (129) Google Scholar Population-based case series may provide a more realistic picture of the actual incidence of pulmonary hypertension: in one such study,4Philen RM Eidson M Kilbourne EM Sewell CM Voorhees R New Mexico Eosinophilia-Myalgia Syndrome Study Group Eosinophilia-myalgia syndrome: a clinical case series of 21 patients.Arch Intern Med. 1991; 151: 533-537Crossref PubMed Scopus (34) Google Scholar researchers found no cases of pulmonary hypertension, and in another study,5Culpepper RC Williams RG Mease PJ Koepsell TD Kobayashi JM Natural history of the eosinophilia-myalgia syndrome.Ann Intern Med. 1991; 115: 437-442Crossref PubMed Scopus (37) Google Scholar researchers found only two such cases. Although the actual frequency of pulmonary hypertension in people with EMS may never be known, Dr. Cheng's suggestion of using echocardiography to monitor the progression of pulmonary hypertension is sound. Echocardiography is certainly one means of obtaining more information on this severe outcome of EMS. The difficulty of determining the health status of patients with EMS and the complications that they may experience highlights the need for a systematic long-term follow-up of these patients. Because the most severe outcomes, such as pulmonary hypertension, although infrequent, can be disabling, thorough documentation of these complications of EMS will lead to a better understanding of this disorder. Pulmonary Hypertension in Patients With Eosinophilia-Myalgia Syndrome or Toxic Oil SyndromeMayo Clinic ProceedingsVol. 68Issue 8PreviewI read with interest the excellent editorial by Philen and Hill entitled “3-(Phenylamino)alanine—a Link Between Eosinophilia-Myalgia Syndrome and Toxic Oil Syndrome?” which was published in the February 1993 issue of the Mayo Clinic Proceedings (pages 197 to 200). Finally, a link between these two intriguing environmental diseases seems to have been established. I disagree, however, with the authors' statement that “chronic pulmonary hypertension occurs in a small percentage” of patients with either disease. Full-Text PDF