Heparin-induced DRESS syndrome in a paediatric patient and successful anaesthetic management in cardiovascular bypass surgery: case report.

BACKGROUND: Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) Syndrome is a severe adverse drug reaction marked by delayed hypersensitivity reactions causing skin and systemic complications. DRESS diagnosis is challenging due to the variety of clinical presentations and symptom overlap with other conditions. The perioperative period in these patients requires precise pharmacological strategies to prevent complications associated with this syndrome. The treatment of DRESS induced by unfractionated heparin during cardiopulmonary bypass (CPB) surgery presents some challenges that must be considered when selecting an anticoagulant to avoid side effects. In this case, bivalirudin, a direct thrombin inhibitor, is indicated as an alternative to heparin in patients undergoing CPB. However, in contrast to heparin/protamine, there is no direct reversal agent for bivalirudin. CASE PRESENTATION: We report the case of an 11-year-old male diagnosed with native aortic valve endocarditis and thrombosis in his left lower extremity. During valvular replacement surgery, systemic unfractionated heparin was administered. Postoperatively, the patient developed fever, eosinophilia and pruritic rash. Warm shock and elevated alanine transaminase (ALT) and aspartate transaminase (AST) levels followed, leading to the diagnosis of DRESS syndrome. Treatment with methylprednisolone resulted in complete resolution of symptoms. Seven years later, the patient was readmitted due to insufficient anticoagulation and a thrombus in the prosthetic aortic valve, presenting a recurrent DRESS episode due to the administration of unfractionated heparin, which was later replaced with low-molecular-weight heparin during hospitalization. Treatment with corticosteroids and antihistamines was initiated, resulting in the resolution of this episode. Ultimately, the patient required the Ross procedure. During this intervention the anticoagulation strategy was modified, unfractionated heparin was replaced with bivalirudin during the procedure and fondaparinux was administered during the postoperative period. This resulted in stable transaminases levels and no eosinophilia. CONCLUSION: The severity of DRESS Syndrome underscores the importance of early recognition, heightened monitoring, and a comprehensive approach tailored to each patient's needs. This particular case highlights the significance of this approach and may have a substantial clinical impact since it provides alternatives to heparin, such as bivalirudin and fondaparinux, in the anticoagulation strategy of CPB for patients who have a hypersensibility reaction to this medication; thus, enhancing clinical outcomes by minimizing risks linked to adverse drug reactions.

Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms. Part II diagnosis and management.

Drug-induced hypersensitivity syndrome, also known as drug reaction with eosinophilia and systemic symptoms, is a severe cutaneous adverse reaction characterized by an exanthem, fever, and hematologic and visceral organ involvement. The differential diagnosis includes other cutaneous adverse reactions, infections, inflammatory and autoimmune diseases, and neoplastic disorders. Three sets of diagnostic criteria have been proposed; however, consensus is lacking. The cornerstone of management is immediate discontinuation of the suspected drug culprit. Systemic corticosteroids remain first-line therapy, but the literature on steroid-sparing agents is expanding. Longitudinal evaluation for sequelae is recommended. Adjunctive tests for risk stratification and drug culprit identification remain under investigation. Part II of this continuing medical education activity begins by exploring the differential diagnosis and diagnosis of drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms and concludes with an evidence-based overview of evaluation and treatment.

Characteristics of DRESS Syndrome in the Elderly: A Comparative Study of 55 Patients.

Background: Drug reaction with eosinophilia and systemic symptoms (DRESS) is a rare drug reaction characterized by a skin rash, eosinophilia, and organ involvement. Objective: Our purpose is to focus on the clinical and epidemiological characteristics of DRESS in the elderly and to identify the incriminated drugs. Methods: This is a retrospective study including patients, hospitalized for DRESS with a RegiSCAR ≥4. The population was divided into 2 groups according to age: 65 years or older (G1) and <65 years (G2). The statistical study was performed using the comparative and multivariate analysis. Results: We included 55 patients (30.9% G1 and 69.1% G2). Skin manifestations were comparable in both groups. Lymphadenopathy was less common in G1 with a statistically significant difference (P = 0.012). Renal impairment was more frequent in the elderly with a statistically significant result (P = 0.005). DRESS in the elderly group was significantly associated with the occurrence of sepsis (P = 0.008). Allopurinol was the most common culprit associated with DRESS in G1 (P = 0.001). Relapses and recurrences were comparable in both groups (P = 0.71). Conclusions: DRESS in the elderly is associated with a high risk of complications, mainly kidney involvement and sepsis. Allopurinol is the most incriminated drug.

Characterization of drug-induced liver injury associated with drug reaction with eosinophilia and systemic symptoms in two prospective DILI registries.

Idiosyncratic drug-induced liver injury (DILI) associated with drug reactions with eosinophilia and systemic symptoms (DRESS) is poorly characterized among patients of Western countries. We aimed to comprehensively assess the clinical characteristics, outcomes, and causative agents in a prospective, well-vetted cohort of DILI patients with DRESS (DILI-DRESS). We identified 53 DILI-DRESS cases from the Spanish DILI Registry and the Latin American DILI Network. For comparison purposes, we defined a group of DILI patients (n = 881). DILI-DRESS cases were younger (47 vs. 53 years, respectively; p = 0.042) and presented more frequently with cholestatic/mixed damage (p = 0.018). Most DILI-DRESS patients showed moderate liver injury, 13% developed severe damage, and only one patient (with hepatocellular injury due to anti-tuberculosis drugs) progressed to acute liver failure and died. DILI-DRESS cases showed a distinctive causative drug pattern compared to DILI cases. The most frequent drugs were carbamazepine (13%), anti-tuberculosis drugs (13%), amoxicillin-clavulanate (11%), and allopurinol and lamotrigine (7.6% each). Among all cases of DILI due to allopurinol and lamotrigine, 67% presented with a DILI-DRESS phenotype, respectively. Higher total bilirubin (TBL) levels at DILI recognition (odds ratio [OR] 1.23; 95% confidence interval [CI] 1.04-1.45) and absence of eosinophilia (OR 8.77; 95% CI 1.11-69.20) increased the risk for developing a severe-fatal injury in DILI-DRESS patients. DILI-DRESS patients have a more frequent cholestasis/mixed pattern of injury at presentation, with antiepileptics as distinctive causative drug class. Most of the lamotrigine and allopurinol cases present with this phenotype. Higher TBL levels and absence of eosinophilia at DILI recognition are markers of poor outcomes.

Eosinophilic fasciitis in a young male auto mechanic exposed to organic solvents.

We report a case of eosinophilic fasciitis in a teenage auto mechanic who was most likely affected by occupational exposure to organic solvents, including the aromatic hydrocarbons benzene, trimethylbenzene, naphthalene, toluene, and xylene. The patient presented with an 8-month history of painful induration of his extremities and an abnormal gait. A deep excisional biopsy of the fascia was obtained, demonstrating subcutaneous fibrosis with perivascular and interstitial inflammation, with lymphocytes and plasma cells spilling into the sclerosed fascia, and focal fibrinoid necrosis. Treatment was begun with intravenous pulse doses of methylprednisolone, prednisone (20 mg daily), and subcutaneous methotrexate (25 mg weekly), and the patient's painful induration had resolved and gait had normalized at the 6-month follow-up. Our case suggests that exposure to organic solvents could be implicated in the pathogenesis of eosinophilic fasciitis and highlights the importance of a thorough occupational history to prevent repeat exposures to potentially causative agents.

Unraveling the complexities of drug reaction with eosinophilia and systemic symptoms (DRESS): Insights into clinical, laboratory, and histopathologic features of a case series from an Italian tertiary center.

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe and potentially life-threatening drug hypersensitivity reaction. The diagnosis and management of DRESS are complicated due to its heterogeneous clinical and pathologic presentations, delayed onset of signs and symptoms, and unpredictable outcome. This retrospective study aimed to analyze cases of DRESS from a single Italian referring tertiary hospital center (Grande Ospedale Metropolitano Niguarda, Milan, Italy) with a focus on clinical features, causative drugs, histopathologic findings, and treatment. We have included 18 of 32 patients with a probable or definite diagnosis of DRESS. The study observed a slight predominance of women, with antimicrobials and allopurinol identified as the main causative drugs. Clinical manifestations varied, with a monomorphic maculopapular eruption being the most common, whereas facial edema and mucosal involvement were less frequently observed. Multiple organs were commonly affected, with liver and kidney involvement being prominent. Cardiac involvement was associated with the severity of eosinophilia. Laboratory evaluations showed elevated eosinophil levels and increased eosinophil cationic protein levels, supporting the role of eosinophils in DRESS pathogenesis. Histopathologic analysis revealed various patterns often coexisting in the same biopsy in 83% of cases, with interface dermatitis being the most frequent, followed by the perivascular pattern and the spongiotic/eczematous pattern. We observed eosinophils in the biopsy samples in about 50% of patients, and the relationship between peripheral eosinophilia and eosinophils in skin biopsies was not significant. In addition to the RegiSCAR score, age may play a role in predicting disease severity, as older patients with lower scores had poorer outcomes. The prognosis of DRESS depended on early identification, discontinuation of the causative agent, and appropriate therapy. Systemic corticosteroids were the primary treatment option.

[DRESS syndrome induced by anti-TB drugs]. / Síndrome de DRESS inducido por fármacos antituberculosos.

OBJETIVE: To describe the phenotype of DRESS syndrome induced by antituberculosis drugs. METHODS: Descriptive study, withdrawn from the review of the records of patients with DRESS syndrome, identified in the interconsultation of the Department of Research in Immunogenetics and Allergy, of the Insti-tuto Nacional de Enfermedades Respiratorias (INER) Ismael Cosío Villegas, among 2014 and 2020. Frequency analysis was performed. The associations between biomarkers and latency are calculated with the χ2 test and log-rank, and the evaluation of the change in the biomarkers with the Wilcoxon test. The value of p < 0.05 is considered statistically significant. For data analysis, the SPSS v.21 program was obtained. RESULTS: 15 patients were identified; represented by 0.02% of total cases treated in the Department for so-meimmuno-allergic condition (15/7052); the main symptomatology were: rash (100%), eosinophilia (93%), fe-ver (80%), adenomegaly (60%), kidney damage (40%), liver damage (33%), and latency of 21 days. Liver damage was associated with prolonged latency (p = 0.02). After treatment, the total levels of eosinophils (p < 0.001) and liver and kidney biomarkers (p < 0.04) decreased. DRESS syndrome induced by antituberculosis drugs is not associated with the number of drugs prescribed or with the pattern of resistance of Mycobacterium tuberculosis. CONCLUSIONS: DRESS syndrome induced by antituberculosis drugs is an atypical clinical reaction, similar to other types of DRESS syndrome that respond favorably to systemic corticosteroids.

OBJETIVO: Describir el fenotipo del síndrome de DRESS inducido por fármacos antituberculosos. MÉTODOS: Estudio descriptivo efectuado a partir de la revisión de los expedientes de pacientes con síndrome de DRESS, identificados en la interconsulta del Departamento de Investigación en Inmunogénetica y Alergia, del Instituto Nacional de Enfermedades Respiratorias (INER) Ismael Cosío Villegas, entre 2014 y 2020. Se realizó análisis de frecuencias. Las asociaciones entre biomarcadores y latencia se calcularon con la prueba de χ2 y log-rank, y la evaluación del cambio en los biomarcadores con la prueba de Wilcoxon. Se consideró esta-dísticamente significativo el valor de p < 0.05. Para el análisis de los datos se utilizó el programa SPSS v.21. RESULTADOS: Se identificaron 15 pacientes, que representaron el 0.2% de los casos atendidos en el Departa-mento por algún padecimiento inmuno-alérgico (15/7052); las principales manifestaciones fueron: exantema (100%), eosinofilia (93%), fiebre (80%), adenomegalia (60%), daño renal (40%), daño hepático (33%) y latencia de 21 días. El daño hepático se asoció con latencia prolongada (p = 0.02). Posterior al tratamiento disminu-yeron las concentraciones totales de eosinófilos (p < 0.001) y biomarcadores hepáticos y renales (p < 0.04). El síndrome de DRESS inducido por fármacos antituberculosos no se asoció con la cantidad de fármacos prescritos ni con el patrón de resistencia de Mycobacterium tuberculosis. CONCLUSIONES: El síndrome de DRESS inducido por fármacos antituberculosos es una reacción clínica atípica, similar a otros tipos de síndrome de DRESS que responden favorablemente a corticosteroides sisté-micos.

Early increase in eosinophil count may predict long-term hypereosinophilia during dupilumab treatment: a 2-year observational study.

KEY POINTS: In a limited subset of patients, dupilumab-induced hypereosinophilia is persistent. Two-month follow-up eosinophil count may predict long-lasting hypereosinophilia.

Immunopathogenic Insights on Preferential Human Herpesvirus-6 Reactivation in Drug Rash With Eosinophilia and Systemic Symptoms: A Scoping Review.

INTRODUCTION: Human herpesvirus-6 (HHV-6) is a ubiquitous lymphotropic betaherpesvirus that can reactivate in drug rash with eosinophilia and systemic symptoms (DRESS). Despite recent publications advancing our understanding of HHV-6 in DRESS, the exact role of HHV-6 in disease pathogenesis remains unclear. METHODS: A scoping review with the PubMed query "(HHV 6 AND (drug OR DRESS OR DIHS)) OR (HHV6 AND (drug OR DRESS OR DIHS))" was conducted in accordance with PRISMA guidelines. Articles containing original data on at least one DRESS patient with HHV-6 testing were included. RESULTS: Our search returned a total of 373 publications, of which 89 met eligibility criteria. HHV-6 reactivation occurred in 63% of DRESS patients (n = 748), which was significantly more often than other herpesviruses. HHV-6 reactivation was associated with worse outcomes and greater severity in controlled studies. Case reports have demonstrated sometimes fatal HHV-6-related multi-organ involvement. Temporally, HHV-6 reactivation typically occurs 2 to 4 weeks after DRESS onset and has been linked to markers of immunologic signaling, such as OX40 (CD134), an HHV-6 entry receptor. Efficacy of antiviral or immunoglobulin treatment has only been demonstrated anecdotally, and steroid use may affect HHV-6 reactivation. CONCLUSION: HHV-6 is implicated in DRESS more than in any other dermatologic condition. It is still unclear whether HHV-6 reactivation is cause or consequence of DRESS dysregulation. Similar pathogenic mechanisms precipitated by HHV-6 in other contexts may be relevant in DRESS. Future randomized controlled studies to assess effects of viral suppression on clinical outcomes is needed.

Gemcitabine-associated DRESS syndrome: A case report.

INTRODUCTION: Gemcitabine is a well-tolerated pyrimidine antimetabolite chemotherapeutic that is increasingly utilized to treat non-small cell lung carcinoma, breast, pancreatic, and urogenital cancers. Myelosuppression is a common side effect and skin rashes can be observed. We discuss a case of the exceedingly rare DRESS syndrome, which appeared following Gemcitabine treatment. CASE REPORT: A 60-year-old patient with pancreatic cancer and liver metastases received therapy with Gemcitabine as a single agent. Fever, itching, and redness started to be reported on the third day of receiving Gemcitabine treatment. The patient's diffuse maculopapular rash steadily got worse, leading to hospitalization. MANAGEMENT AND OUTCOME: In the patient's physical examination, a high fever, hepatomegaly, and a diffuse macular papular rash were detected, an increase in eosinophils in the complete blood count and peripheral blood. A skin biopsy was performed. It was determined that the patient had Gemcitabine-associated DRESS syndrome. Antihistamines and local steroids were administered. On the fifth day following treatment, skin lesions and eosinophilia decreased. DISCUSSION: The most common cause of DRESS syndrome, a disorder marked by extensive skin eruption, fever, eosinophilia, and systemic symptoms, is medication use. Infections including HHV-6, EBV, and CMV can occasionally be the reason. Gemcitabine is one of the medications that is frequently used in cancer, and a case was provided because the literature review did not mention Gemcitabine-related DRESS syndrome.

Eosinophilic granulomatosis with polyangiitis developed after dupilumab administration in patients with eosinophilic chronic rhinosinusitis and asthma: a case report.

BACKGROUND: Eosinophilic granulomatosis with polyangiitis (EGPA) is a form of anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis characterized by eosinophil-rich granulomatous inflammation and small-to-medium vessel vasculitis associated with asthma, rhinosinusitis, and eosinophilia. EGPA is often difficult to distinguish from severe asthma and eosinophilic chronic rhinosinusitis (ECRS) in cases when there are no findings that suggest vasculitis. Dupilumab, an anti-IL-4Rα monoclonal antibody, is expected to be effective in eosinophilic airway inflammatory diseases, such as refractory asthma and chronic rhinosinusitis (CRS). Although transient eosinophilia and eosinophilic pneumoniae have been reported in patients with refractory asthma and CRS associated with dupilumab, few studies have examined the development of EGPA. CASE PRESENTATION: We report a case of a 61-year-old woman treated with dupilumab for refractory ECRS and eosinophilic otitis media (EOM) complicated by severe asthma. Although she had a previous history of eosinophilic pneumoniae and myeloperoxidase (MPO) ANCA positivity, there were no apparent findings of vasculitis before the initiation of dupilumab. After the second administration of dupilumab, several adverse events developed, including worsening of ECRS, EOM and asthma, and neuropathy. A blood test showed an eosoinophilia and re-elevation of MPO-ANCA levels after the administration of dupilumab. Therefore, dupilumab was discontinued owing to the development of EGPA, and prednisolone and azathioprine administration was initiated for a remission induction therapy. CONCLUSION: To the best of our knowledge, this is the first case report that suggests that dupilumab may directly trigger the manifestation of vasculitis in patients who were previously MPO-ANCA-positive. Although the precise mechanism of how dupilumab could trigger the development of EGPA requires further elucidation, measuring MPO-ANCA in patients with multiple eosinophilic disorders before the initiation of dupilumab might be helpful when considering the possibility of a latent EGPA. When administering dupilumab to patients with a previous history of MPO-ANCA positivity, clinicians must carefully monitor and collaborate with other specialists in the pertinent fields of study for appropriate usage.

Cyclosporine as an alternative immunosuppressant for steroid-resistant drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome.

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a multiorgan reaction associated with a broad range of commonly used medications. Most cases of DRESS syndrome resolve with cessation of the inciting agent; however, use of systemic immunosuppression, most commonly with oral corticosteroids, is also recommended in cases with visceral organ involvement.We report a case of steroid-resistant relapsing-remitting DRESS syndrome secondary to sulfasalazine. Our patient experienced significant flare of symptoms of DRESS syndrome with multiple attempts to wean prednisolone. Initiation of cyclosporine as an alternative immunosuppressive agent to long-term corticosteroids has resulted in a 6-month remission in both dermatological and hepatic sequelae of DRESS syndrome.

IL-33 induces histidine decarboxylase, especially in c-kit+ cells and mast cells, and roles of histamine include negative regulation of IL-33-induced eosinophilia.

OBJECTIVE AND METHODS: IL-33 is present in endothelial, epithelial, and fibroblast-like cells and released upon cell injury. IL-33 reportedly induces mast-cell degranulation and is involved in various diseases, including allergic diseases. So, IL-33-related diseases seem to overlap with histamine-related diseases. In addition to the release from mast cells, histamine is newly formed by the induction of histidine decarboxylase (HDC). Some inflammatory and/or hematopoietic cytokines (IL-1, IL-3, etc.) are known to induce HDC, and the histamine produced by HDC induction is released without storage. We examined the involvement of HDC and histamine in the effects of IL-33. RESULTS: A single intraperitoneal injection of IL-33 into mice induced HDC directly and/or via other cytokines (including IL-5) within a few hours in various tissues, particularly strongly in hematopoietic organs. The major cells exhibiting HDC-induction were mast cells and c-kit+ cells in the bone marrow. HDC was also induced in non-mast cells in non-hematopoietic organs. HDC, histamine, and histamine H4 receptors (H4Rs) contributed to the suppression of IL-33-induced eosinophilia. CONCLUSION: IL-33 directly and indirectly (via IL-5) induces HDC in various cells, particularly potently in c-kit+ cells and mature mast cells, and the newly formed histamine contributes to the negative regulation of IL-33-induced eosinophilia via H4Rs.

Cycle-dependent eosinophilia due to adjuvant nivolumab for malignant melanoma.

INTRODUCTION: Immune checkpoint inhibitors (ICIs) have been widely used in the contemporary anticancer armamentarium. However, new side effects due to these agents have continued to emerge. CASE REPORT: We describe herein a 71-year-old patient who received nivolumab as adjuvant therapy for malignant melanoma of the skin. He developed eosinophilia starting at 4 weeks of therapy. Eosinophilia increased progressively during the first six nivolumab cycles, then stabilized. Cycle-dependent increments were observed. Subsequently, the patient experienced well-known side effects of ICIs such as grade 1 diarrhea, arthralgias, and erythematous papular rash. MANAGEMENT AND OUTCOME: Nivolumab was continued, and absolute eosinophil counts were monitored. Prednisone 10 mg PO daily was required for moderate gastroenteritis, dermatitis, and arthritis, which all subsequently improved. Eosinophil levels gradually downtrended after starting prednisone. Causality assessment between nivolumab and eosinophilia via adverse drug reaction (ADR) probability scale revealed a score of 9. DISCUSSION: Physicians and pharmacists need to be aware of this important side effect of ICI therapy. Eosinophilia in the context of ICI use has been previously reported in clinical trials. Our case is unique as eosinophilia was cumulative, showed increments every 8 weeks, and exhibited a trend toward cycle dependency. Extensive and expensive workup does not appear warranted, and simple monitoring of complete blood count is appropriate in most patients. Further studies are necessary to assess the true incidence, pattern, and severity of eosinophilia related to ICIs as well as its association with clinical outcomes.

Skin reaction with Eosinophilia and Systemic Symptoms after lenalidomide in peritoneal Dialysis.

The Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) syndrome is a fatal and immune-mediated idiosyncratic drug reaction, with symptoms of fever, skin eruptions (that involves more than half of the body surface), facial oedema and hematological disorders, all presenting within the latent period following drug intake. Effects can also be seen on multiple organs, most notably hepatitis in liver and acute interstitial nephritis in kidney, generally post-administration of allopurinol. The European Registry of Severe Cutaneous Adverse Reactions (RegiSCAR) classifies the DRESS Syndrome cases as "definite", "probable" or "possible", based on clinical and laboratory features. Different pathogenetic mechanisms have been involved in this disease, including immunological reactions and HHV-6 reactivation. In our experience, a 72-year-old male, affected by myeloma in peritoneal dialysis, developed a rare case of DRESS syndrome after lenalidomide administration (less than ten cases are known) with HHV-6 reactivation. According to literature, we withdrew the drug and gave methylprednisolone 0,8 mg/kg orally and IVIG 1 gr/kg for two days. Despite this therapy, DRESS syndrome relapsed during steroid taper with rash, thrombocytopenia, hepatitis and high troponin level. A single cycle of intravenous immunoglobulin 0,5 g/kg for four days was enough for syndrome remission. Only few cases are reported in literature, but because of the increasing use of lenalidomide and the autoimmune sequelae of DRESS syndrome, a broad workup and a multidisciplinar careful approach could help in diagnosis, treatment and follow-up.

Clozapine-Induced Fever and Plasma Cytokine Changes in a Patient With Schizophrenia.

INTRODUCTION: Clozapine-induced fever is frequently documented in the early stages of administration. Fever during clozapine treatment often presents a clinical challenge, because there are no established guideline to decide when fever is the adverse effect. Although the etiology of clozapine-induced fevers remains unknown, evidence has suggested that fever may develop secondarily to a generalized inflammatory response as a manifestation of the immune-modulating effects of clozapine. CASE PRESENTATION: We presented a 59-year-old male patient with a treatment-resistant schizophrenia, who was introduced clozapine for the first time. He became febrile on day 14 at 75 mg/d. He was diagnosed clozapine-induced fever, which was improved by dose reduction on day 27 at 25 mg/d. However, we noticed significant high levels of blood urea nitrogen and serum creatinine on day 29, which resulted in withdrawal of clozapine. Also, we found continuous eosinophilia on day 33. After we provided conservative therapy with appropriate intravenous fluids, his kidney function and eosinophilic counts returned to normal on day 59 and day 53, respectively. The time-sequential changes of levels of interleukin 6 and tumor necrosis factor α suggested that the upregulated cytokines play a role on clozapine-induced fever and subsequent eosinophilia under severe renal failure condition. CONCLUSIONS: To our knowledge, this is the first case presentation of clozapine-induced fever discussing the mechanism, differential diagnosis, and decision making of clozapine treatment focusing on plasma cytokines. If once fever occurs, an extensive medical workup for the fever and a careful systemic medical management should be promptly proceeded to avoid clozapine-associated severe complications.

Drug rash with eosinophilia and systemic symptoms syndrome masquerading as a lymphoproliferative disorder in a young adult on immunosuppressive therapy for rheumatoid arthritis: a case report.

BACKGROUND: This case reveals a novel presentation of drug rash with eosinophilia and systemic symptoms syndrome that mimics a lymphoproliferative disorder. The heterogeneous clinical presentation of drug rash with eosinophilia and systemic symptoms syndrome gives rise to a broad differential diagnosis that includes a multitude of infectious, inflammatory, and autoimmune conditions. This patient was diagnosed with drug rash with eosinophilia and systemic symptoms syndrome 4 weeks after starting sulfasalazine and 5 weeks after starting hydroxychloroquine for rheumatoid arthritis. Both of these medications have been shown to cause drug rash with eosinophilia and systemic symptoms syndrome, albeit more rarely in the context of hydroxychloroquine. This patient's history, physical examination, and workup illuminate a case of drug rash with eosinophilia and systemic symptoms syndrome that masquerades as a lymphoproliferative disorder despite its adherence to the RegiSCAR criteria. CASE PRESENTATION: A 22-year-old African-American female with an atopic history and rheumatoid arthritis presented for evaluation of a rash, unremitting fevers, and syncope. She was found to have drug rash with eosinophilia and systemic symptoms syndrome. A syncope workup was unremarkable. Computed tomography of the chest/abdomen/pelvis confirmed extensive lymphadenopathy and revealed a small right pleural effusion (Fig. 5). These imaging findings accompanied by fevers and a rash in the setting of eosinophilia, leukocytosis, and transaminitis led to the clinical suspicion for drug rash with eosinophilia and systemic symptoms syndrome. Steroids were subsequently initiated. Broad-spectrum antibiotic therapy was implemented to cover for possible skin/soft tissue infection due to initial paradoxical worsening after discontinuation of the culprit drugs. Lymph node biopsy ruled out a lymphoproliferative disorder and instead demonstrated necrotizing lymphadenitis. An extensive infectious and autoimmune workup was noncontributory. Clinical improvement was visualized, antibiotics were discontinued, and she was discharged on a steroid taper. CONCLUSION: This case reflects how drug rash with eosinophilia and systemic symptoms syndrome can masquerade as a lymphoproliferative disorder. Additionally, it highlights the extent to which rapid identification and treatment optimized the patient's outcome. It calls into question how immunogenetics may factor into a patient's susceptibility to acquire drug rash with eosinophilia and systemic symptoms syndrome. This case is unique because of the early onset of visceral organ involvement, the type of internal organ involvement, the hematopoietic features, and the lymphadenopathy associated with a disease-modifying antirheumatic drug.

Bosutinib-induced late-onset severe liver injury preceded by eosinophilia.

Tyrosine kinase inhibitors (TKIs) have dramatically changed the way chronic myeloid leukemia (CML) is treated. Although TKI therapy improves the overall survival of patients with CML, the management of various adverse events (AEs) from the therapy has become a major barrier to its adherence. Bosutinib is a second-generation TKI and an effective first-line treatment for CML. The most frequent AE is diarrhea; however, liver toxicity is also a major complication. In general, drug-induced hepatic enzyme elevation occurs within 1-2 weeks after treatment initiation. However, we noticed that, in a certain number of patients, liver injury appeared late (4-7 weeks) and was accompanied by eosinophilia. Herein, we retrospectively analyzed patients with CML treated with bosutinib at the Juntendo University School of Medicine and observed five patients with CML who developed late-onset liver injury with an elevation of the eosinophil count. In all cases, the liver enzyme level was within the normal range or grade 1 during the first 3 weeks of the bosutinib treatment and then elevated steeply thereafter. The pattern of hepatic toxicity was hepatocellular injury. In addition, all cases of eosinophilia tended to precede or coincide with an elevated liver enzyme level. Thus, the elevation of the eosinophil count may be a predictor for bosutinib-induced liver injury. Careful attention should be paid to delayed-onset hepatic injury, especially at 4-6 weeks after bosutinib initiation.

A rare case of eosinophilic gastritis induced by nivolumab therapy for metastatic melanoma.

Cancer immunotherapy using immune checkpoint inhibitors can cause immune reactions at various sites as a side effect called immune-related adverse events (irAEs). The gastrointestinal tract is susceptible to irAEs, however, the degree and presentation vary considerably from case to case. A 76-year-old woman was diagnosed with anal mucosal melanoma. She underwent radical surgery and received postoperative adjuvant therapy. However, because new metastases were also found in bilateral inguinal lymph nodes, immunotherapy with nivolumab was performed. Approximately 10 months after the initiation of nivolumab administration, she presented with epigastric discomfort and nausea, and her laboratory data showed severe eosinophilia (1938/mm3). Computed tomography demonstrated a diffuse thickening of the gastric wall. Esophagogastroduodenoscopy and endoscopic ultrasonography showed mucosal thickening due to edema, and histologic examination revealed severe invasion of eosinophils in the lamina propria. Subsequently, she was diagnosed with eosinophilic gastritis due to irAEs induced by nivolumab. Oral administration of prednisolone rapidly normalized her endoscopic and histologic findings, dramatically reducing her symptoms. This is a very rare and important case report of nivolumab-induced severe eosinophilic gastritis. Although gastric lesions as IrAEs is rare, it is necessary to differentiate eosinophilic gastritis if unexplained nausea occurred during the administration of immune checkpoint inhibitors.