The Dapsone Hypersensitivity Syndrome revisited: a potentially fatal multisystem disorder with prominent hepatopulmonary manifestations

4,4'-Diaminodiphenylsulphone (Dapsone) is widely used for a variety of infectious, immune and hypersensitivity disorders, with indications ranging from Hansen's disease, inflammatory disease and insect bites, all of which may be seen as manifestations in certain occupational diseases. However, the use of dapsone may be associated with a plethora of adverse effects, some of which may involve the pulmonary parenchyma. Methemoglobinemia with resultant cyanosis, bone marrow aplasia and/or hemolytic anemia, peripheral neuropathy and the potentially fatal dapsone hypersensitivity syndrome (DHS), the focus of this review, may all occur individually or in combination. DHS typically presents with a triad of fever, skin eruption, and internal organ (lung, liver, neurological and other systems) involvement, occurring several weeks to as late as 6 months after the initial administration of the drug. In this sense, it may resemble a DRESS syndrome (Drug Rash with Eosinophilia and Systemic Symptoms). DHS must be promptly identified, as untreated, the disorder could be fatal. Moreover, the pulmonary/systemic manifestations may be mistaken for other disorders. Eosinophilic infiltrates, pneumonitis, pleural effusions and interstitial lung disease may be seen. This syndrome is best approached with the immediate discontinuation of the offending drug and prompt administration of oral or intravenous glucocorticoids. An immunological-inflammatory basis of the syndrome can be envisaged, based on the pathological picture and excellent response to antiinflammatory therapy. Since dapsone is used for various indications, physicians from all specialties may encounter DHS and need to familiarize themselves with the salient features about the syndrome and its management

Urticaria and Urticarial Vasculitis

Urticaria and urticarial vasculitis may be triggered by allergens, infection, autoimmunity and other immunological conditions. Careful evaluation, skin biopsy and specific laboratory tests can assist in diagnosis. The appropriate use of antihistamines, glucocorticoids, and other immunomodulators are discussed

Exercise-Induced Anaphylaxis: A Serious but Preventable Disorder

Described for the first time approximately 30 years ago, exercise-induced anaphylaxis is a rare disorder characterized by development of a severe allergic response occurring after mild-to-strenuous physical activity. This disorder is especially important to recognize with the recent increase in physical activity and health fitness fads. A number of predisposing factors (eg, prior ingestion of particular food groups) linked to exercise-induced anaphylaxis has been outlined over the years. Mechanisms govern big the condition are still being unveiled, and it is likely that one mechanism involves mast cell degranulation and inflammatory mediator generation resulting from the biochemical effects of exercise, sometimes in the presence of an ingested allergen such that wheat or shell fish. Clinical manifestations usually occur after around 10 minutes of exercise, and follow a specific sequence, starting with pruritis and widespread urticarial lesions, evolving into a more typical anaphylactic picture with respiratory distress and vascular collapse. Fatality is exceedingly rare, with only one documented casein the literature. There is an overlap of symptoms with other syndromes (such as systemic mastocytosis and cholinergic urticaria), and these should be remembered when establishing a differential. Treatment of exercise-induced anaphylaxis consists of immediate stabilization geared toward the anaphylactic response with epinephrine and antihistamines. The patient needs to be educated on preventive measures and equipped with an epinephrine autoinjector in the event of an emergency. Exercise-induced anaphylaxis remains a potentially serious disorder, and the health care provider should be aware of its clinical features and effective management strategies

Appearance of Drug-Resistant Tuberculosis in Rural Tennessee

Drug-resistant tuberculosis (DRTB) is a growing national health concern in both urban populations and rural areas and is exacerbated by the growing epidemic of human immunodeficiency virus (HIV) infection. Between 1989 and 1992, 7 cases of DRTB (5 with multidrug-resistance) were diagnosed in an eight-county region of East Tennessee. During 1990 and 1991 alone, 5 of 100 patients with tuberculosis had drug-resistant strains (5%). All 7 patients with DRTB had 100% resistance to isoniazid; 5 also had resistance to streptomycin, 2 to rifampin, and 1 to pyrazinamide and ethambutol. All patients were white, U.S.-born, and without evidence of HIV infection. Contact investigation revealed that more contacts of patients with DRTB (13 of 74,18%) were infected than were contacts of patients with drug- sensitive tuberculosis (46 of 290,16%). Our study demonstrates that DRTB is not confined to geographically distinct areas, but may be a subtle and easily missed diagnosis in presumably low-risk rural populations

Acinetobacter Baumannii Pneumonia: A Case Report and Review of the Literature

Bacteria that constitute the genus Acinetobacter were originally identified in the first decade of the 20th century. However, it was not until the last decade that its role as an opportunistic pathogen was fully appreciated. It is now clear that Acinetobacter is an important cause of nosocomial infection and contributes significantly to the patient\u27s morbidity and mortality. The prevalence of infection with A. baumannii has increased significantly during the last decade. At the same time, A. baumannii has developed one of the most impressive patterns of antibiotic resistance ever observed, establishing it as an important nosocomial pathogen. It has been nicknamed the Gram-negative MRSA because of its frequent resistance to commonly used antibiotics. Infection with A. baumannii should be suspected in hospitalized patients who are not responding to initial empiric antibiotic treatment, and the therapeutic approach should be customized according to when the pathogen is isolated

Refractory Cough as a Remote Manifestation of Retroperitoneal Liposarcoma

Retroperitoneal liposarcoma is often asymptomatic but sometimes attention is drawn to the neoplasm due to clinical manifestations. These include fever, flu-like symptoms, nausea or vomiting due to pressure or hypoglycemia related to paraneoplastic disease. We present a rare case of a massive retroperitoneal liposarcoma presenting with refractory dry cough. The patient underwent resection of the mass with complete resolution of her cough. Histopathological examination of the mass demonstrated a well-differentiated tumor with myxomatous features. No evidence of metastatic disease to the lungs was observed. This case points to the need for a thorough and careful evaluation of unexplained cough

Recognizing the Impact of Obstructive Sleep Apnea in Patients With Asthma

The coexistence of asthma and obstructive sleep apnea (OSA) in a given patient presents a number of diagnostic and treatment challenges. Although the relationship between these 2 diseases is complex, it is clear that risk factors such as obesity, rhinosinusitis, and gastroesophageal reflux disease (GERD) can complicate both asthma and OSA. In the evaluation of a patient with poorly controlled asthma, it is important to consider the possibility of OSA. The most obvious clues are daytime sleepiness and snoring, but the definitive diagnosis is made by polysomnography. Management of OSA may include weight loss and continuous positive airway pressure (CPAP). Surgical intervention, such as uvulopalatopharyngoplasty, may be an option for patients who cannot tolerate CPAP. Management may include specific therapies directed at GERD or upper airway disease as well as modification of the patient\u27s asthma regimen

Obstructive Sleep Apnea, Inflammation, and Cardiopulmonary Disease

Obstructive sleep apnea (OSA) occurs commonly in the U.S. population and is seen in both obese as well as non-obese individuals. OSA is a disease characterized by periodic upper airway collapse during sleep, which then results in either apnea, hypopnea, or both. The disorder leads to a variety of medical complications. Neuropsychiatric complications include daytime somnolence, cognitive dysfunction, and depression. Increased incidence of motor vehicle accidents has been documented in these patients and probably reflects disordered reflex mechanisms or excessive somnolence. More importantly, vascular disorders such as hypertension, stroke, congestive cardiac failure, arrhythmias, and atherosclerosis occur frequently in these patients. The lungs may be affected by pulmonary hypertension and worsening of asthma. Recent data from several laboratories demonstrate that obstructive sleep apnea is characterized by an inflammatory response. Cytokines are elaborated during the hypoxemic episodes leading to inflammatory responses as marked clinically by elevated C-reactive protein (CRP). As elevated CRP levels are considered markers of the acute phase response and characterize progression of vascular injury in coronary artery disease, it is likely that obstructive sleep apnea could lead to worsening of vasculopathy. Moreover, as inflammatory mechanisms regulate bronchial asthma, it is also likely that cytokines and superoxide radicals generated during hypoxemic episodes could exacerbate reactive airway disease. Patients with Cough, Obstructive sleep apnea, Rhinosinusitis, and Esophageal reflux clustered together can be categorized by the acronym, CORE , syndrome. The purpose of this manuscript is to review the inflammatory responses that occur in patients with obstructive sleep apnea and relate them to the occurrence of cardiopulmonary disease