Biomedical subjects
Richard D deShazo
Publications and source records attributed to Richard D deShazo.
Indoor fire ant sting attacks: a risk for frail elders.
OBJECTIVE: We have previously reported 10 indoor sting attacks by imported fire ants, most of which involved frail elderly people in the Southeastern United States. Since the range of these insects is expanding and attacks often attract media attention, we hypothesized that additional attacks of which we were unaware may have occurred and were reported in local newspapers. METHODS: We searched the archives from 1989 until 2004 of 182 US newspapers in fire ant endemic areas in 10 states. RESULTS: Ten additional cases of indoor fire ant sting attacks were reported in local newspapers between 1991 and 2004. This brings the total to 16 attacks on adults and four on infants. Most adult attacks occurred in long-term care facilities, but three involved hospitalized patients. Morbidity ranged from nightmares to death in seven adults. One of the infants died and two suffered long-term morbidity. Six of the 20 sting victims died within 1 week of the attack. Seven of the 10 attacks reported in newspapers did not result in significant medical consequences, as compared with only two of the 10 attacks in previously published reports. CONCLUSION: Increasing numbers of indoor fire ant sting attacks are occurring in the United States, and frail elderly people and infants are at risk. They should be removed from indoor areas where ants are present until the ants are eradicated.
Adverse reactions to ants other than imported fire ants.
OBJECTIVE: To identify ants other than Solenopsis invicta and Solenopsis richteri reported to cause adverse reactions in humans. DATA SOURCES: We conducted a literature review to identify reports of medical reactions to ants other than S. invicta and S. richteri. Our review of medical and entomological literature on stinging ants was generated from MEDLINE and FORMIS, respectively, using the key words stinging ants and ant stings. The search was limited to articles in English published from 1966 to 2004 on MEDLINE and all years on FORMIS. We also present 3 new case reports of severe reactions to stings by 2 different species of ants, Pseudomyrmex ejectus and Hypoponera punctatissima. STUDY SELECTION: Articles that concerned anaphylactic (IgE-mediated) or anaphylactic-like (resembling anaphylaxis but mechanism unknown) immediate reactions to ant stings or bites were included in this review. RESULTS: Taken together, our data demonstrate that S. invicta and S. richteri are not alone in their capability to cause serious allergic or adverse reactions. A diverse array of ant species belonging to 6 different subfamilies (Formicinae, Myrmeciinae, Ponerinae, Ectatomminae, Myrmicinae, and Pseudomyrmecinae) and 10 genera (Solenopsis, Formica, Myrmecia, Tetramorium, Pogonomyrmex, Pachycondyla, Odontomachus, Rhytidoponera, Pseudomyrmex, and Hypoponera) have now been shown to have this capability. CONCLUSION: Awareness that species other than imported fire ants may cause severe reactions should lead to more rapid evaluation and treatment and further investigation of the medical entomology of these ants.
Southern society founders' medal acceptance.
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Fire ant attacks on patients in nursing homes: an increasing problem.
We review the medical reports of fire ant attacks on residents of nursing homes in the context of the medical entomology of these insects, and present recommendations to prevent and manage future attacks. Two reports were recent cases, while a computer-assisted search yielded four other similar cases of attacks by foraging fire ants in the last 10 years. One patient experienced an anaphylactic reaction and 4 patients died within 1 week of the attack. Ants were usually noted in health care facilities days before the attacks. The presence of fire ants around immobile, often cognitively impaired, patients seems to be the primary risk factor for massive fire ant attacks. Health care providers and administrators in fire ant endemic areas must be aware that the presence of fire ants in hospitals and nursing homes represents a hazard. Fire ant infestation can lead to sting attacks on patients, causing respiratory tract obstruction, worsening of pre-existing medical conditions, or frank anaphylaxis. All the attacks reported here have resulted in legal action involving physicians and health care facilities.
Biological control of fire ants: an update on new techniques.
OBJECTIVE: To review the present understanding of biological control methods for imported fire ants (IFAs). DATA SOURCES: We searched MEDLINE, Biological Abstracts, and the US Department of Agriculture Formis Ant Literature database. STUDY SELECTION: All articles published in the last 10 years on biological control of fire ants were selected. RESULTS: The decapitating flies Pseudacteon tricuspis, Pseudacteon curvatus, and Pseudacteon litoralis have been successfully released in the United States. The continued releases of multiple species of decapitating flies will expand the area of impact, applying greater pressure on IFA populations throughout the southern United States. The microsporidium Thelohania solenopsae causes the slow demise of a fire ant colony. The advantages of T. solenopsae as a biological control agent include debilitation of queens, specificity for IFAs, self-sustaining infections, and lower relative tolerance to chemical pesticides. Solenopsis daguerrei has also been shown to have detrimental effects on IFA colony growth, the number of sexual reproductives produced, and the number of host queens in multiple queen colonies; however, this parasite is difficult to rear in the laboratory and to introduce into IFA colonies. CONCLUSIONS: It is unlikely that IFAs can be completely eradicated from the United States. However, technology using chemicals and/or natural control agents could eventually maintain populations at low levels if an integrated approach is used for control.
Allergic reactions to Triatoma bites.
BACKGROUND: Triatoma bugs are best known in the medical community as vectors of trypanosomiasis (Chagas disease). However, bites of Triatoma bugs are a cause of local cutaneous reactions and anaphylaxis, mainly in the western and southwestern United States. The reactions typically occur at night during sleep, and the bite may not be recognized. There is continuing public interest in medical complications of bites of these bugs, although the scope of the problem remains undefined. OBJECTIVE: To review the relevant medical literature, identify present knowledge, and determine future research goals for allergy to Triatoma. DATA SOURCES: Computerized databases were used to search the medical literature for articles in the English language on Triatoma bites, allergy and entomology, and Chagas disease. STUDY SELECTION: Almost all identified articles on Triatoma allergy were used. Only selected articles on Triatoma bites and entomology were pertinent to the objectives. Articles on Chagas disease were limited to cases in the United States. RESULTS: Bites of Triatoma bugs have been known to cause anaphylaxis for more than a century. These insects inhabit a large area of the United States, but to date most reports of allergic reactions to their bites have originated in the West and Southwest. The reactions typically occur at night during sleep following a bite on uncovered skin and may be unrecognized. Procalin has been identified as the major salivary allergen of Triatoma protracta and was recently cloned and expressed through recombinant technique. Allergenic reactivity has been demonstrated to salivary gland extracts of 2 species. The extracts of these 2 species have not shown immunologic cross-reactivity. Immunotherapy using a salivary gland extract appeared to be beneficial in a small number of patients; however, no commercial testing or treatment allergen is available. CONCLUSIONS: Triatoma bites appear to be an important cause of anaphylaxis, especially in the western and southwestern United States. Because exposure to these insects often occurs during sleep, the incidence of allergic reactions to them is unclear. An epidemiologic study should be performed to determine the incidence, prevalence, and range of allergic responses to the bites of these insects. The lack of commercial antigen limits diagnostic and treatment capabilities. The development of an allergen under the Orphan Drug Act should be encouraged.
Molecular mechanisms of allergic disease.
Interaction of allergen with T-cells is associated with patterns of cytokine release by immunocompetent cells characterized as T-helper Th1 or Th2 T-immune responses. The Th2 pattern of inflammation induced by this cytokine release is associated with allergic diseases. The molecular mechanisms underlying allergic inflammation are the signals for immunoglobulin (Ig) E production and the activation of mast cells and eosinophils. Data suggesting that environmental exposure may play a role in the induction of the Th2 pattern of inflammation has led to the development of the "hygiene hypothesis." Knowledge of the mechanisms of allergic inflammation has allowed the development of specific pharmacologic intervention to include 1) antibodies to IgE, 2) therapy tailored to regulate IgE production, and 3) modulation of cytokine release and function. Knowledge of the role of transcription factors in regulating gene activity as it relates to allergic inflammation is expanding and may also provide future targets for pharmacologic intervention.
Allergic and nonallergic drug reactions.
Allergic drug reactions may be difficult to distinguish from nonallergic reactions. In this article, we review a pragmatic approach to the management of adverse drug reactions on the basis of knowledge of the classification and patterns of these reactions. Algorithms for management of patients with a previous adverse drug reaction who require treatment for the same indication, and the approach to a patient who experiences a drug reaction while on multiple drugs, are presented.
Rhinosinusitis.
History, physical examination, and allergy testing may distinguish the syndromes of rhinitis, classified as allergic, infectious, perennial, nonallergic, and miscellaneous. All may be associated with sinusitis, probably on the basis of obstruction of the osteomeatal complex. Although topical nasal steroids are useful in the treatment of all forms of rhinitis, diagnosis of the offending type in a given patient is necessary for optimal management.
APM's mission to lead Academic Internal Medicine.
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Sinobronchial allergic mycosis: the SAM syndrome.
We contend that the presence of concomitant allergic fungal sinusitis (AFS) and allergic bronchopulmonary mycosis in the same patient represents an expression of the same process of fungal hypersensitivity in the upper and lower airways. We have termed this process the SAM syndrome, an acronym for sinobronchial allergic mycosis. Diagnostic criteria have been established for the SAM syndrome, and the clinical characteristics of one previously unreported and four previously reported patients have been tabulated. Patients with the SAM syndrome have chronic sinusitis involving multiple sinuses, asthma, immediate cutaneous reactivity to fungal allergens, peripheral eosinophilia, and radiographic evidence of bronchiectasis. Total serum IgE levels are usually elevated as well. A variety of chest radiographic abnormalities may occur, ranging from mass lesions to diffuse pulmonary infiltrates and even normal findings on chest radiographs. Patients present for an evaluation of either sinus or lung disease and, at that time, demonstrate no clinical features that distinguish them from patients with isolated sinus or lung disease. All patients reported to date have had clinical responses to therapy with corticosteroids. We postulate that SAM is underdiagnosed in patients with AFS, a disease recently reported from medical centers in the southeastern and western United States. Moreover, since our patient had a mutation in the cystic fibrosis transmembrane conductor regulator (CFTR) gene, we further hypothesize that CFTR gene mutations may play an important role in the pathogenesis of the SAM syndrome.
Recommendations for prevention and management of fire ant infestation of health care facilities.
The range of imported fire ants now includes most of the southeastern United States, parts of the Southwest, portions of the East and West Coasts, and Puerto Rico. Increasingly, fire ant attacks on patients in health care facilities have been reported. In this paper, we provide recommendations for fire ant control in and around health care facilities that should help prevent building infestation and further attacks. In addition, we provide algorithms detailing fire ant prevention strategies (indoors and outdoors) and patient management after fire ant stings. Physicians in areas endemic for fire ants should be aware of the possibility that patients may be harmed by these insects, and also should be generally familiar with measures used to control fire ants.