Eosinophilia-myalgia syndrome was described in 1989 in patients who presented progressive and incapacitating myalgia and eosinophilia in blood, fluids and secretions. Most patients report previous L-tryptophan intake. Respiratory manifestations are found in up to 80% of the cases, occasionally as the only manifestation. Treatment includes drug discontinuation and administration of corticosteroids. Here, we describe the case of a 61-year-old female admitted with acute respiratory failure after using L-tryptophan, hydroxytryptophan and other drugs. The patient presented eosinophilia, together with elevated eosinophil counts in the bronchoalveolar lavage and pleural effusion. After discontinuation of the drugs previously used, corticosteroids were administered, resulting in clinical and radiological improvement within just a few days.336747751Ahmed MM, Mubashir E, Sairam S, Lisse JR. Eosinophilia-Myalgia Syndrome. [monograph on the Internet]. e-medicineWebMDc1996-2006 [cited 2006 May 5]. Available from: http://www.emedicine.com/med/topic693.htm#section~workupHerrick, M.K., Chang, Y., Horoupian, D.S., Lombard, C.M., Adornato, B.T., L-tryptophan and the eosinophilia-myalgia syndrome: Pathologic findings in eight patients (1991) Hum Pathol, 22 (1), pp. 12-21Tazelaar, H.D., Myers, J.L., Drage, C.W., King Jr, T.E., Aguayo, S., Colby, T.V., Pulmonary disease associated with L-tryptophan-induced eosinophilic myalgia syndrome. Clinical and pathologic features (1990) Chest, 97 (5), pp. 1032-1036Campagna, A.C., Blanc, P.D., Criswell, L.A., Clarke, D., Sack, K.E., Gold, W.M., Golden, J.A., Pulmonary manifestations of the eosinophilia-myalgia syndrome associated with tryptophan ingestion (1992) Chest, 101 (5), pp. 1274-1281Ballone, G.J., (2005) Serotonina. [monograph on the Internet] Psiqwebc, , http://virtualpsy.locaweb.com.br/index.php?sec=61&art=295, cited 2006 Oct 4, Available fromShapiro, S., L-tryptophan and eosinophilia-myalgia syndrome (1994) Lancet, 344 (8925), pp. 817-819Shapiro, S., Epidemiologic studies of the association of L-tryptophan with the eosinophilia-myalgia syndrome: A critique (1996) J Rheumatol Suppl, 46, pp. 44-58. , discussion 58-9Clauw, D.J., Pincus, T., The eosinophilia-myalgia syndrome: What we know, what we think we know, and what we need to know (1996) J Rheumatol Suppl, 46, pp. 2-6de Kerviler, E., Trédaniel, J., Revlon, G., Groussard, O., Zalcman, G., Ortoli, J.M., Fluoxetin-induced pulmonary granulomatosis (1996) Eur Respir J, 9 (3), pp. 615-617Williamson, M.R., Edison, M., Rosenberg, R.D., Williamson, S.L., Eosinophilia-myalgia syndrome: Findings on chest radiographs in 18 patients (1991) Radiology, 180 (3), pp. 849-851Hertzman, P.A., Criteria for the definition of the eosinophilia-myalgia syndrome (1996) J Rheumatol Suppl, 46, pp. 7-12Pincus, T., Eosinophilia-myalgia syndrome: Patient status 2-4 years after onset (1996) J Rheumatol Suppl, 46, pp. 19-24. , discussion 24-5Margolin, L., Non-L-tryptophan related eosinophilia-myalgia syndrome with hypoproteinemia and hypoalbuminemia (2003) J Rheumatol, 30 (3), pp. 628-629Silver, R.M., Pathophysiology of the eosinophilia-myalgia syndrome (1996) J Rheumatol Suppl, 46, pp. 26-36Swygert, L.A., Maes, E.F., Sewell, L.E., Miller, L., Falk, H., Kilbourne, E.M., Eosinophilia-myalgia syndrome. Results of national surveillance (1990) JAMA, 264 (13), pp. 1698-1703Clinical spectrum of eosinophilia-myalgia syndrome - California (1990) MMWR Morb Mortal Wkly Rep, 39 (6), pp. 89-91. , Centers for Disease Control CDCBanner, A.S., Borochovitz, D., Acute respiratory failure caused by pulmonary vasculitis after L-tryptophan ingestion (1991) Am Rev Respir Dis, 143 (3), pp. 661-664Strumpf, I.J., Drucker, R.D., Anders, K.H., Cohen, S., Fajolu, O., Acute eosinophilic pulmonary disease associated with the ingestion of L-tryptophan-containing products (1991) Chest, 99 (1), pp. 8-13