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Peripheral and tissue eosinophilia can be a prominent feature of several unique rheumatologic and vascular diseases. These diseases span a wide range of clinical features, histologic findings, therapeutic approaches, and outcomes. Despite the rare nature of these entities--which makes large-scale studies challenging--knowledge has continued to grow regarding their epidemiology, pathophysiology, and management. This review compares and contrasts 5 rheumatologic and vascular conditions in which eosinophilia can be seen: eosinophilic granulomatosis with polyangiitis (Churg-Strauss), immunoglobulin G4-related disease, diffuse fasciitis with eosinophilia, eosinophilia-myalgia syndrome, and eosinophilic myositis., (Copyright © 2015 Elsevier Inc. All rights reserved.)

We presented two cases with symptoms of diffuse swelling of subcutaneous tissue, stiffness and tenderness of involved areas, fever, eosinophilia and hypergammaglobulinemia. The inflammatory infiltrates consisting of lymphocytes, plasma cells and eosinophils were yielded in fascia. The difficulties in differentition of the symptoms between eosinophilic fasciitis and "eosinophilia-myalgia syndrome" are discussed.

A 51-year-old physically active man was investigated for exertional myalgias and muscle stiffness. On examination he had mild proximal muscle weakness of the upper extremities and retraction of the digit flexors. Blood eosinophilia was present, but serum creatine kinase (CK) levels and an electromyographic study were normal. A skin-fascia-muscle biopsy of the calf revealed a macrophagic and CD4+ T-cell infiltration of the perimysium, and a T-cell expansion was observed in blood, bone marrow, and muscle. A diagnosis of eosinophilic perimyositis was made, and prednisone and azathioprine were administrated with a good clinical response. This case highlights the differential diagnosis of blood eosinophilia with muscle disorders, and underscores that eosinophilic perimyositis may be the expression of a T-cell monoclonal expansion. Although the pathogenesis behind the T-cell expansion is unclear but probably inflammatory, we suggest regular follow-up to allow early treatment of any T-cell lymphoproliferative malignancy that may develop.

Objective: To identify the specific nature of the neurocognitive impairments of eosinophilia-myalgia syndrome (EMS) in an unselected population, and to present longitudinal patterns., Methods: A consecutive sample of 23 patients with EMS and 18 age and education matched control subjects were assessed on a comprehensive neuropsychological battery. Longitudinal results were gathered from six patients., Results: Neurocognitive impairments were found which represent a subset of deficits reported in previous group and case study reports. Deficits were limited to complex visual memory, conceptual set shifting, and attention, which suggest a selective dysexecutive syndrome. The motor slowing and verbal memory deficits previously reported were not found. Although depression, fatigue, sleep deprivation, and pain were significant symptoms, they were unassociated with deficits with the exception of an association of depression with one deficit. There was no pattern of overall decline over time in a subset of the group, although considerable heterogeneity in the longitudinal patterns of neurocognitive tests was found. Abnormalities of white matter appeared in the MRI of eight of 12 patients., Conclusions: The neurocognitive and neuroimaging findings contribute to the evidence which indicates that the neural substrate of EMS is white matter damage.

Significant morbidity and mortality occur during the acute phase of the eosinophilia-myalgia syndrome (EMS), and many patients still have chronic manifestations of the disease. Although the precise etiologic agent or agents within implicated batches of L-tryptophan remain uncertain, histopathologic studies support a role for a cell mediated immune response underlying the pathophysiology of EMS. The cellular immune response seems to lead to a microangiopathy and release of cytokines that can induce eosinophilia and fibrosis. Such responses are most marked within the dermis, subcutis, fascia, and connective tissue in and around muscles, nerves, and other tissues. The pathophysiology of the chronic symptoms is poorly understood but may involve ischemia, neuropathy, and metabolic abnormalities.

The eosinophilia-myalgia syndrome was associated with the ingestion of L-tryptophan products containing a number of contaminants, one of which has been identified as 1,1'-ethylidene-bis-(L-tryptophan) (EBT), also known as peak E or peak 97. In earlier studies, we demonstrated that EBT induces inflammation and fibrosis in dermal and subcutaneous tissue of C57BL/6 mice. Others have shown EBT to be a potent stimulus for fibroblast activation and collagen synthesis in vitro, and dermal tissue from EMS patients reveals evidence of enhanced collagen gene expression. In the present study using Northern blot analysis and in situ hybridization, we demonstrate enhanced expression of genes for types I, III, and VI collagen in the dermis and subcutis of C57BL/6 mice treated with EBT for 3-21 days. Increased type I procollagen mRNA was noted on day 6 of EBT treatment and was followed by enhanced expression of type III and VI procollagen mRNA at day 21. L-Tryptophan, free of contaminants associated with the eosinophilia-myalgia syndrome epidemic, increased dermal collagen mRNA to a lesser extent than did EBT. Increased procollagen gene expression was accompanied by evidence of enhanced TGF-beta 1 expression in the dermis and subcutis. This animal model provides additional evidence for EBT as a causal agent of the eosinophilia-myalgia syndrome and should prove useful in the study of the pathogenesis of that syndrome.

Background: In a previous study, we did follow-up on 418 patients who were exposed to tryptophan in 1989, of whom 47 (11%) had definite and 63 (9%) possible eosinophilia-myalgia syndrome (EMS)., Methods: We assessed mortality and clinical spectrum of illness since 1989 for 242 (58%) of the 418 tryptophan-exposed patients from the original study. To assess outcomes, we used hospital and death records, interviewer-administered questionnaires, physical examinations, and laboratory tests., Results: During the follow-up interval, mortality from all causes was 19% in those with definite EMS, 7% in possible EMS, and 3% in those who were not ill. The age- and sex-adjusted mortality in those with definite EMS was more than 3 times that of the general population or of tryptophan users in the practice who were not ill. Six deaths (66%) among the definite EMS case patients occurred during the 18 months immediately after symptom onset. Compared with the tryptophan users who were not ill, survivors with definite EMS continued to report excess morbidity for 6 major EMS symptoms (myalgia, arthralgia, weakness, rash, alopecia, and sclerodermiform skin changes), but they also reported that the symptom number and severity diminished with time. None of the tryptophan users who were not ill in 1989 developed a symptom complex suggesting new EMS during the follow-up interval., Conclusions: This study assessing a tryptophan-exposed population found those persons who developed EMS during the 1989 epidemic were at increased risk for death, particularly early after disease onset. Survivors reported improvement or resolution of major symptoms, suggesting that the severity of EMS diminishes with time. We found no evidence of delayed onset of EMS in tryptophan users who were not ill in 1989, regardless of the brand used.

Acute eosinophilia-myalgia syndrome (EMS) due to contaminated L-tryptophan (LT) exposure is an inflammatory microangiopathy of the dermis, fascia, and muscle. Select individuals evolve from acute EMS to have persistence of myalgia, fatigue, cramps, and skin changes for years. Many develop memory dysfunction and confusion. The objective of this study is to delineate the pathology in individuals with chronic EMS. Seventeen patients with ongoing symptoms representing chronic EMS are studied by skin, fascia, and muscle biopsies four to five years after exposure to contaminated LT and initial onset of EMS. All have microvascular disease. Most have lymphocytic inflammatory infiltrates. Several have dermal sclerosis. The findings indicate that persistent microvascular disease is present in chronic EMS. The pathologic changes are similar to those of acute EMS but with notable differences. Tissue eosinophil infiltration is rare in the chronic state as compared to acute EMS. The persistence of endothelial pathology indicates continuing microvascular dysfunction.

The authors describe a case of eosinophilic fasciitis diagnosed 14 years after the onset of the clinical and laboratory manifestations of the disease. Failure to carry out an adeguate histopathological examination during this period played a role in delaying diagnosis.

1,1'-Ethylidenebis[tryptophan] (EBT), a derivative of L-tryptophan (LT), is a trace contaminant in batches of LT implicated by epidemiologic evidence in the pathogenesis of the eosinophilia-myalgia syndrome (EMS). We treated female Lewis rats with EBT or unimplicated LT (4 mg per 100 grams daily) by intraperitoneal injection. No rash or weakness occurred in either group. All three EBT rats had a few necrotic muscle fibers. In two rats, perimysium and fascia were abnormally thickened and infiltrated with lymphocytes, macrophages, and sparse eosinophils; two rats had sparse perineurial inflammatory cells. Rats treated with unimplicated LT showed no abnormality. These findings replicate an important feature of human EMS and support the epidemiologic evidence linking EBT to the pathogenesis of the human disease.

Objective: To determine whether L-5-hydroxytryptophan (L-5-HTP) associated with eosinophiliamyalgia syndrome (EMS) like illness contains impurities in a fashion similar to that described in L-tryptophan associated with EMS., Methods: Members of a family who became ill after exposure to L-5-HTP were evaluated at the National Institutes of Health. Data from patients with extended exposure to L-5-HTP were also examined. Samples of L-5-HTP were examined using high performance liquid chromatography., Results: One member of the family had EMS, and 2 others had eosinophilia. No patient in the other group reviewed developed the syndrome, although 2 patients developed eosinophilia. The L-5-HTP used by the family contained an impurity not present in samples from the other patient group. After replacement with L-5-HTP not containing this impurity, eosinophilia in 2 family members resolved., Conclusion: Some L-5-HTP contains impurities that may be related to L-5-HTP associated EMS.

Eosinophilia-myalgia syndrome, a recently described illness, reached epidemic proportions in 1989 and was linked to the ingestion of L-tryptophan containing trace amounts of several contaminants. Eosinophilia-myalgia syndrome shares many clinical and pathologic similarities with toxic-oil syndrome, an epidemic linked to the ingestion of adulterated cooking oil that occurred in Spain in 1981, and to diffuse fasciitis with eosinophilia, a condition first described in 1974. Over the past year, much work has been done in understanding the etiology and pathogenesis of eosinophilia-myalgia syndrome and toxic-oil syndrome. Follow-up data detailing the long-term sequelae and mortality rates for these two conditions are becoming available. The results from these studies are reviewed in this paper.

A recently recognized disease, the eosinophilia-myalgia syndrome, is described and presented as a new condition attributable to nutritional toxicology. Its etiology is related to the ingestion of L-tryptophan, manufactured by a single Japanese supplier who had modified its production system, which, though of high purity, contained in minute concentrations a number of contaminants or impurities. Patients with eosinophilia-myalgia syndrome develop an eosinophilia with pathologic changes mainly involving skin, muscle, and connective tissue. The findings suggest an autoimmune response. Experimental studies with the implicated L-tryptophan as well as with some contaminants have as yet failed to develop a suitable animal model of eosinophilia-myalgia syndrome. Further studies are needed to unravel the pathogenesis of this complex syndrome. At present, physicians need to be cognizant of this recent syndrome and be aware that other new diseases, induced by nutritional toxicological alterations and possibly related to technicological developments, lie ahead.

Inflammatory lesions of coronary arteries and cardiac neural structures are postmortem histopathologic features of both the eosinophilia-myalgia syndrome (EMS) and the toxic oil syndrome (TOS). The inflammation is primarily lymphocytic. For further definition of the lymphocytes, immunohistochemical analysis was carried out in the hearts of three victims of EMS and four victims of TOS. Many CD45RO+ T cells, OPD4+ helper/inducer T (Th) cells, and CD20+ B cells were observed in these neurovascular lesions, notably in the conduction system and the coronary chemoreceptor. T cells were prominent in EMS around nerves, ganglia, and sometimes around arteries. B cells and Th cells, however, were more prominent in TOS around arteries. The percentage of T cells in EMS (59.6 +/- 2.4%) was significantly higher than in TOS (45.0 +/- 4.2%), whereas that of B cells was significantly higher in TOS (27.7 +/- 4.4%) than in EMS (17.5 +/- 1.3%) (p < 0.01, respectively). There was no significant difference between the syndromes in the percentages of Th cells. Therefore cytotoxic/suppressor T cells are more prominent in EMS than in TOS. These findings suggest that (1) cellular immune mechanisms are involved in cardioneuropathy in victims of both EMS and TOS; (2) cell-mediated cytotoxicity directed against chemoreceptor neural structures and sinus nodal myocytes is prominent in EMS; and (3) some humoral factors may also be involved in the pathogenesis of TOS.

The eosinophilia-myalgia syndrome (EMS) is a recently described disease that has been associated with the ingestion of L-tryptophan containing trace amounts of several impurities. The first such contaminant to be identified and linked epidemiologically to the EMS epidemic was 1,1'-ethylidenebis(L-tryptophan) (EBT), but its role in the etiology and pathogenesis of the syndrome has been controversial. We report the development of inflammation and fibrosis affecting the dermis and subcutis, including the fascia and perimyseal tissues, after the daily intraperitoneal administration of EBT to female C57BL/6 mice. Such changes are accompanied by increased numbers of mast cells, many of which appear to be degranulating. Plasma levels of quinolinic acid, a metabolic product of L-tryptophan via the kynurenine pathway, are reduced initially, and then become elevated when inflammation and fibrosis are more pronounced. The nature and location of the inflammatory cell infiltrate and fibrosis, as well as the presence of mast cells and alterations of L-tryptophan metabolism, are consistent with findings reported in patients with EMS. This murine model suggests that EBT may have been one of the mediators of EMS and should facilitate studies of the pathogenesis of EMS.

Three patients with eosinophilia-myalgia syndrome linked to consumption of L-tryptophan supplement developed a severe sensorimotor axonal neuropathy. All three had myalgia, elevated eosinophil count, and later developed fasciitis. Neuropathy was found at all stages of the illness and resulted in disability which was irreversible despite cessation of L-tryptophan. Nerve conduction studies showed reduced motor and sensory evoked response amplitudes with select sparing of some nerves and the arms were more involved than the legs. Cerebrospinal fluid protein content was increased in one of two patients so tested. Creatine kinase was normal and muscle biopsy showed perimysial inflammation. Sural nerve biopsy in one case showed epineural perivascular inflammation. Our data showed that a severe sensorimotor axonal neuropathy occurs in eosinophilia-myalgia syndrome, suggestive of mononeuritis multiplex.

Objective: We report the first case of restrictive cardiomyopathy occurring in a patient with the eosinophilia-myalgia syndrome., Design: In this article, we discuss the various clinical manifestations of the eosinophilia-myalgia syndrome., Material and Methods: In a 46-year-old woman with the eosinophilia-myalgia syndrome, orthopnea, chronic persistent edema, and severe dyspnea on exertion developed 2 years after she had discontinued use of L-tryptophan. Doppler echocardiography showed ventricular filling confined to early diastole and no atrial filling during ventricular systole--the Doppler hallmarks of restrictive disease. Right-sided cardiac catheterization revealed that the pulmonary wedge pressure equaled the pulmonary artery diastolic pressure and the mean right atrial pressure. A myocardial biopsy specimen showed dense endocardial fibrosis. Special immunofluorescent stains for eosinophilic granule major basic protein showed substantial deposition along the endocardial myocardial interface, an indication that eosinophils were present some time in the past., Results: A follow-up telephone call 14 months after the patient's initial assessment at the Mayo Clinic revealed that she had class III symptoms of congestive heart failure. She was receiving high doses of three diuretics daily, and her condition had improved considerably since her first examination at our institution., Conclusion: Restrictive cardiomyopathy may occur in the setting of the eosinophilia-myalgia syndrome and should be considered in patients with this disease in whom exertional dyspnea and peripheral edema occur.

Five magnetic resonance (MR) studies of the lower leg were performed in three patients with eosinophilia-myalgia syndrome (EMS). The 1H spectroscopic and imaging findings were compared with seven examinations of age-matched healthy controls. Standard imaging with proton density-, T1-, and T2-weighted spin-echo (SE) sequences at 1.5 T showed marked atrophy of the calf muscles and slightly increased signal strength of muscle tissue in T2-weighted SE images. The application of frequency selective chemical shift imaging (SENEX) exhibited skin changes similar to those of scleroderma with increased water content and thickened cutis in the water selective images. In one patient the tibialis muscles showed irregular structures, but no fatty degeneration as demonstrated in the fat selective images. Proton signals from volume elements of (20 mm)3 within the soleus and gastrocnemius muscle were recorded by the PRESS localization method. A reduction of the creatine/water and the choline/water ratios was found in the 1H spectra from the EMS patients compared to the controls. Localized 1H spectroscopy exhibited modified distributions of the lipid signals in two EMS patients with slightly elevated signals from unsaturated fatty acids. The transverse relaxation of choline and creatine signals was accelerated in both examinations of one patient compared with the healthy controls.

Background and Design: We sought to determine if growth factors of potential pathogenetic significance are deposited in the skin, muscle, and peripheral nerve lesions of eosinophilia-myalgia (EMS) and toxic oil syndrome. Immunohistochemical studies using affinity-purified peroxidase-conjugated antibodies to detect transforming growth factor-beta, platelet-derived growth factorAA and growth factorBB, fibroblast growth factor, epidermal growth factor, and interleukin 4 were performed on formalin-fixed, paraffin-embedded specimens. Seven skin biopsy specimens from EMS, six skin biopsy specimens from toxic oil syndrome, nine muscle biopsy specimens from EMS, and one sural nerve biopsy specimen from EMS were studied., Results: Growth factor staining was noted primarily in the epidermis and periappendageal locations of the dermis. The presence of TGF-beta and platelet-derived growth factorAA in the periappendageal dermis was significantly more prevalent in EMS than toxic oil syndrome (57% vs 0%). Prominent staining of transforming growth factor-beta was also present in the perimysial connective tissue of five (63%) of eight EMS muscle biopsy specimens and one sural nerve biopsy specimen., Conclusions: These studies implicate transforming growth factor-beta and platelet-derived growth factorAA as potentially important cytokines in EMS and suggest that the pathogenesis of tissue fibrosis in EMS and toxic oil syndrome may be dependent on different growth factors.

Objective: To determine if the severity of subacute symptoms in eosinophilia-myalgia syndrome (EMS) was affected by medical history or use of nutritional supplements other than tryptophan before illness., Design and Study Population: A case-control study was conducted of EMS cases systematically sampled from all those reported to a statewide surveillance system in California in 1989. Excluding two previous EMS-related deaths, interviews were completed in 73% (57/78) of the eligible case patients sampled., Main Outcome Measures: The severity of any myalgia(s), dyspnea, or walking impairment during each of the first 3 months of EMS was quantified by means of self-reported integer scores ranging from 0 (asymptomatic) to 10 (severe symptoms). Case patients in the top tercile of combined, unweighted monthly scores were defined as having severe symptoms., Results: All interviewees (57 of 57) had consumed supplemental tryptophan before illness; 89% (51/57) were female. The odds of severe symptoms were not significantly associated with gender, age, previous antidepressant use, or cumulative amounts of supplemental tryptophan consumed before or after EMS onset (P > .1). Previous consumption of any multivitamin(s), however, was associated with significantly lower odds of severe symptoms (adjusted odds ratio, 0.05; 95% confidence limits, 0.007, 0.4; P = .006)., Conclusions: The consumption of multivitamin-containing supplements before EMS appears to have modified the severity of subacute symptoms in this sample of cases from California.

Objective: To investigate the pathogenetic mechanisms responsible for the cutaneous fibrosis in eosinophilia-myalgia syndrome (EMS) associated with L-tryptophan ingestion., Methods: Compare in vitro type I collagen production and steady state procollagen mRNA levels in cultured skin fibroblasts derived from healthy individuals and from 5 patients with EMS and diffuse cutaneous induration., Results: Cell lines derived from the affected skin from patients with EMS exhibited greater collagen production and higher steady state levels of alpha 1(I) procollagen mRNA compared with fibroblasts from age and sex matched healthy individuals. Exposure to interferon gamma reduced collagen synthesis in the EMS fibroblast lines. The rate of in vitro transcription of the COL1A1 gene was 30% higher in nuclei isolated from collagen overproducer EMS fibroblasts than in nuclei from normal fibroblasts., Conclusion: Fibroblasts derived from the involved skin of patients with EMS show increased expression of the alpha 1(I) procollagen gene in vitro compared to normal skin fibroblasts. The biosynthetically activated phenotype exhibited by EMS fibroblasts appears to be due, at least in part, to transcriptional activation of type I collagen gene expression. These biochemical and molecular alterations may result in accumulation of collagen and lead to the cutaneous fibrosis in EMS.

Eosinophilia-myalgia syndrome is an idiopathic disorder characterized by myalgia, especially of the extremities and peripheral eosinophilia. It is found in some patients as a result of tryptophan ingestion. We examined four patients showing clinical features and muscle biopsy changes consistent with eosinophilia-myalgia syndrome. The results of conventional histology were compared with immunohistochemical studies using monoclonal antibodies to human T lymphocytes, macrophages, HLA-DR antigen. Our findings confirm the potential importance of lymphocytes and macrophages in this syndrome. In particular, new observations are presented concerning the immunoreactivity of HLA-DR antigen.

To determine the immunopathogenesis of the persistent symptoms of patients with eosinophilia-myalgia syndrome (EMS) induced by L-tryptophan, we performed immunocytochemical studies on 10 muscle and fascia biopsy specimens obtained during the acute disease and the chronic persistent connective tissue sclerosis. A series of monoclonal antibodies was used in a single- or double-immunostaining technique to detect and quantify T-cell subsets, macrophages, major histocompatibility complex antigens, eosinophilic basic protein-positive cells, and resting fibroblasts expressing Thy-I antigen or activated fibroblasts expressing the activation marker F-19. We found inflammatory cells consisting of CD8+ cells (45% +/- 8.9%), T4 cells (36% +/- 10.1%), and macrophages (19% +/- 12%), scattered or perivascularly in the fascia, the perimysium, and the endomysial septae. Only rare granulated or degranulating eosinophils were noted. Many muscle fibers around fascicles or near blood vessels expressed major histocompatibility complex-I antigens. The mean number of fibroblasts in the fascia, the perimysial connective tissue, and the spindle capsule was increased in the EMS patients' specimens compared with the endomysial cells seen in six disease-control muscle biopsy specimens from patients with chronic inflammatory myopathies or dystrophies (P < .01). Up to 70% of the fibroblasts in EMS were activated and up to 30% of them expressed HLA-DR antigen. In the disease controls up to 29% of the fibroblasts were activated but none expressed DR. Repeat muscle biopsy a year later in a patient whose symptoms persisted showed reduced inflammation but an increased number of activated fibroblasts and enhanced DR expression. We conclude that in EMS there is a T-cell-mediated process against components of the extracellular matrix, including fibroblasts, in the fascia and the perimysium that persists even years after the drug is discontinued. Because the fibroblasts are activated and aberrantly express DR antigen, they may be the target cells playing a role in the continuing clinical and histologic signs of tissue sclerosis.

A 16-year-old white male with acute biphenotypic leukemia developed evidence of the eosinophilia myalgia syndrome associated with total parenteral nutritional support with solutions containing tryptophan, which were given during his initial induction chemotherapy and also after autologous marrow transplantation. He developed pronounced eosinophilia and a vasculitic skin rash, myalgias of the abdomen, upper trunk, and neck, and died of respiratory distress with no evidence of an infectious etiology. Autopsy revealed diffuse vasculitis involving the heart, lungs, kidneys, testes, spleen, liver, skin, gut wall and marrow with neuritis of gut wall nerves and ganglia. Thus, the eosinophilia myalgia syndrome can be associated with parenteral tryptophan administration.

L-tryptophan (LT) has been implicated as a causal agent in the recently recognized eosinophilia-myalgia syndrome (EMS). Pulmonary complications occur in up to 60% of patients. Lung biopsies have shown chronic interstitial pneumonia, mild eosinophilia, vasculitis and perivasculitis, and hypertensive pulmonary arteriopathy. Open lung biopsies from two women who developed respiratory symptoms associated with LT EMS were studied with a panel of antibodies to lymphoid cells, by transmission electron microscopy and by direct immunofluorescence for immunoglobulin and complement. The majority of the cells infiltrating the interstitium and around vessels were T-cells, with a predominance of CD8+ cells. Numerous alveolar macrophages were also identified. Rare polyclonal B-cells were also present. Ultrastructural studies confirmed the presence of interstitial and perivascular lymphocytes as well as occasional eosinophils. The inflammatory cells were also present in vessel cells. Fibrointimal thickening was not observed in the sections studied ultrastructurally. Immunofluorescent staining for IgG, IgA, C3, C4, albumin, kappa, and lambda was negative. There was scattered staining for fibrinogen in alveolar spaces. The etiology of LT EMS is still under investigation, although a contaminant acting in conjunction with host factors is the favored hypothesis. The results of this study indicate that T cytotoxic/suppressor cells may be intimately involved in the pathogenesis of the lung injury.

The L-tryptophan eosinophilic myalgia syndrome (EMS) clinically has some similarities with idiopathic eosinophilic fasciitis (EF). In order to study the pathology of both syndromes, we analyzed 21 biopsies of patients with EMS and 8 with idiopathic EF. In both diseases there is dermal and fascial mucin and dermal edema, but this was more common in EMS. EMS is also characterized by dilated lymphatics, dermal and septal sclerosis and macrophage-rich inflammation. Neural inflammation was seen in 4 of the cases with EMS and in none with idiopathic EF. In both syndromes, there are many histopathological similarities. The differences may be due to sampling and to sample size. The nerve lesions of EMS may result from the nature of lymphocyte-macrophage inflammation, or the effect of the eosinophil neurotoxin and may not be a primary event.

The eosinophilia-myalgia syndrome (EMS) is a newly recognized illness that occurred in an epidemic form during the summer of 1989. The illness was characterized in the acute phase by myalgia and eosinophilia, followed in many patients by chronic cutaneous lesions, progressive neuropathy, and myopathy. EMS was associated with ingestion of L-tryptophan, an essential amino acid marketed as a nutritional supplement but widely used as a therapeutic agent. Evidence of abnormal L-tryptophan metabolism has been described in patients with EMS, and most likely reflects increased activity of indoleamine 2,3-dioxygenase, the rate-limiting enzyme of tryptophan metabolism. A contaminant identified in EMS-associated L-tryptophan preparations has been isolated and characterized, but its biologic effects and role as the etiologic agent in EMS remain to be established. Pathologic observations and experimental studies indicate that eosinophils, mononuclear inflammatory cells, and fibroblasts are potential effector cells, and interleukin-5 and transforming growth factor-beta are important mediators in the pathogenesis of the syndrome. Although few new cases of EMS occurred following the withdrawal of L-tryptophan, affected patients continue to manifest late sequelae of the disease, including dermal fibrotic conditions. This tragic outbreak of a newly recognized illness has focused interest on the role of chemical and environmental agents in the pathogenesis of various idiopathic illness characterized by tissue inflammation and fibrosis.

A patient with eosinophilia-myalgia syndrome developed progressive central nervosa system involvement that did not improve despite discontinuation of L-tryptophan therapy. Neurologic impairment was manifested initially by spastic monoparesis, which was improved by treatment with methyl-prednisolone and hydroxyurea. Recurrence of weakness was accompanied by gait ataxia, dysphagia, and complaints of a gradual decline in memory and concentration. Neuropsychological testing identified a broad pattern of cognitive deficits suggestive of a subcortical dementia, and magnetic resonance imaging demonstrated multiple high-signal lesions in the white matter. Cognitive deficits appear to be underrecognized in patients with the eosinophilia-myalgia syndrome. The response of our patient's initial symptoms to corticosteroid therapy suggests a possible role for autoimmune mechanisms in the pathogenesis of central nervous system involvement in the eosinophilia-myalgia syndrome. Neuropsychological evaluation should be performed in patients with cognitive complaints to delineate the full spectrum of central nervous system impairment associated with the eosinophilia-myalgia syndrome.

We report the cutaneous manifestations of the eosinophilia-myalgia syndrome in 10 patients, with specific reference to their clinical course, histopathological features, and immunogenetic studies. Cutaneous manifestations could be classified into three groups: morphoea-like sclerosis, urticarial and papular lesions, and generalized sclerosis. Despite this polymorphic clinical presentation, the histopathological abnormalities in all cases were strikingly similar, and consisted of superficial and deep perivascular lymphocytic dermal infiltrates, mucin deposition, and fascial inflammation (often in the absence of sclerosis). Immunoperoxidase studies revealed increased numbers of factor XIIIa- and MAC 387-positive cells in the inflammatory infiltrate. Immunogenetic studies demonstrated that 77% (7/9) of patients possessed the HLA-DR3 or HLA-DR4 phenotypes. Mean follow-up of 24 months after discontinuation of L-tryptophan revealed the presence of persistent severe disabling disease in 30% of patients.

Eosinophilia-myalgia syndrome (EMS) is a newly recognized disorder, characterized by myalgia, weakness, scleroderma-like changes, and eosinophilia. EMS is associated with lots of L-tryptophan allegedly contaminated with byproducts of the manufacturing process. We describe 3 patients with EMS who presented with a severe demyelinating sensorimotor polyneuropathy. Electrodiagnostic studies revealed multifocal conduction block, slowing and temporal dispersion of motor responses, and prolonged or absent F-responses. Despite plasmapheresis; corticosteroids; and, in 1 patient, cyclophosphamide, 2 patients died and the remaining patient experienced minimal recovery. Pathology revealed patchy perivascular infiltrates and fibrosis in the connective tissue of muscle and nerve. Autopsy of the central nervous system in 2 patients did not reveal changes unique to EMS. In addition to other organ involvement, EMS may manifest as a potentially fatal polyneuropathy, which initially appears to have prominent demyelinating features.

After 2 weeks of ingestion of 130 g L-Tryptophan a 52 year old female develops an Eosinophilia Myalgia Syndrome with acute onset of deep venous thrombosis of forearm and possible initial cardiac manifestation featuring intermittent sinustachykardia. This is followed by a severe chronic disease (follow-up 15 months) with diffuse scleroderma and sensomotoric polyneuropathia. The deep muscle biopsy-specimen shows mononuclear infiltration of fascia and interstitial myositis with rare eosinophils. A blood eosinophilia (900/ul) occurs only in the initial acute onset of the illness. Plasma level of Kynurenine is significantly high (4000 pmol/ml), collagenneosynthesis is activated (Procollagen type III peptid 0.927 U/ml). No significant clinical improvement was seen with Acathioprine (100 mg/d) and Prednisolon (40-60 mg/d), after treatment with Ciclosporin scleroderma regresses completely, polyneuropathy is persisting.

A retrospective study (1985-1989) of patients suffering from diffuse fasciitis with eosinophilia revealed that five of eight patients had taken L-tryptophan-containing drugs before the onset of the disease. In addition, since this drug-disease association was first described five patients have been diagnosed during the year 1990. All ten patients developed peripheral eosinophilia, myalgia and deep skin involvement indistinguishable from eosinophilic fasciitis. Corticosteroids were able to reduce the pain and inflammatory parameters, but did not prophylactically improve the long-standing sclerodermalike skin thickening. In 2/5 patients with symptoms longer than 1 year, low-dose corticosteroid maintenance therapy has been continuously required to control joint and muscle pain.

We report a case of repeated coronary artery spasm with myocardial injury in a 37-year-old woman with the eosinophilia-myalgia syndrome. This patient did not have a medical history of cardiac-related illness or risk factors for coronary artery disease. The presence of eosinophil granule major basic protein in otherwise normal-appearing myocardial tissue, along with normal plasma levels of tryptophan metabolites, suggests that the mechanism of vasospasm in this patient might involve toxic eosinophil proteins or focal myocardial lesions, but not the production of excess tryptophan metabolites.

The eosinophilia-myalgia syndrome (EMS) associated with the ingestion of L-tryptophan (LT) containing products has recently been recognized in the United States. We report the histologic features of the cutaneous scleroderma-like changes in four patients. All of the patients met the Center for Disease Control criteria for EMS and had a history of LT ingestion. Skin biopsies showed increased dermal mucin and dermal sclerosis, with trapping of adnexal structures. There are clinical and histologic similarities between EMS, scleroderma, the toxic oil syndrome, and fasciitis with eosinophils.

We report a 45-year-old female who had symptomatic gastrointestinal involvement, eosinophils in the cellular infiltrate, and who proved to have L-tryptophan-associated eosinophilia-myalgia syndrome. This case illustrates that gastrointestinal disease can be a major, seemingly primary clinical presentation in this syndrome, and that a drug history, specifically L-tryptophan, needs to be included in the differential diagnosis of "eosinophilic gastroenteritis."

Eosinophilia-myalgia syndrome (EMS) is a disorder characterized by generalized muscle pain and eosinophilia. The etiology of this syndrome appears to be related to the ingestion of L-tryptophan. Most studies to date describe an associated peripheral neuropathy or combined myopathy and peripheral neuropathy. This report presents 2 EMS patients with myopathy, confirmed by muscle biopsy in 1 case and electrophysiology in both cases. No clinical evidence of neuropathy was found. Both routine and single fiber electromyography failed to demonstrate abnormalities, suggesting neuropathy. Electrodiagnostic abnormalities paralleled the clinical course. After 10 months, both patients continued to have symptoms of muscle cramping and reduced endurance, with mild electromyographic abnormalities, perhaps reflecting changes in their motor unit.

Eosinophilia-myalgia syndrome (EMS) is a newly described syndrome associated with use of L-tryptophan. A neuropathy with features of axonal degeneration has also been described in conjunction with EMS. Demyelinating polyneuropathy is not a well recognised association of the syndrome. The two patients with EMS reported presented with profound weakness and sensory loss and were found to have clinical, electrophysiological and pathological evidence of a chronic demyelinating polyneuropathy. The concurrence of this neuropathy with EMS, as well as several other features of their illness, is suggestive of an immune mediated mechanism in the pathophysiology of EMS.

We describe the histopathologic changes of skin, muscle, vessels, and fascia in 11 patients with eosinophilia myalgia syndrome, a newly described entity that has been linked to the ingestion of L-tryptophan. This syndrome is defined clinically by severe incapacitating myalgias and a peripheral eosinophilia. Arthralgias, edema of the extremities, morbilliform rashes, skin induration, weakness, fatigue, and respiratory weakness may be present as well. The earliest apparent histologic changes were observed at the septa between subcutaneous fat lobules and in the deep dermis or fascia. The septa and fascia were infiltrated with a sparse mixture of lymphocytes and histiocytes. In the deep fascia, in addition to inflammatory cells, there were distinctive, reactive mesenchymal cells that showed features of both histiocytes and fibrocytes. Minimal tissue eosinophilia was seen despite the extent of blood eosinophilia. Dermal thickening and homogenization of collagen bundles occurred with replacement of fat and adnexa (changes indistinguishable from scleroderma or morphea). Vessel walls in the dermis and fascia showed thickening and endothelial swelling, but no overt vasculitis was noted. Skeletal muscle biopsies showed a perimysial, epimysial, and/or fascial inflammatory infiltrate of lymphocytes and distinctive reactive mesenchymal cells with some eosinophils. Minimal myofiber atrophy, regeneration, or necrosis was seen despite the clinical history of severe myalgias in almost all patients. This syndrome should help gain insight into the mechanisms of fibrosis in environmental-induced, scleroderma-like syndromes and in idiopathic, scleroderma-like disorders as well.

The author reports a case of eosinophilia-myalgia syndrome (EMS), not associated with the use of tryptophan. Other nutritional supplements should be considered as possible etiologic agents in EMS. Further research in this area is needed.