By K. Sugut. Kansas Wesleyan University.
Detection of cat allergen ( Fel d 1) in homes or schools never known to have cat exposure is consistent with transport of Fel d 1 into such premises and sensitivity of immunoassays for cat allergen generic olanzapine 7.5 mg without a prescription symptoms heart attack women. The removal of an animal from a home and covering a mattress and pillow properly are interventions known to decrease the concentration of allergen below which many patients do not have clinical asthma symptoms discount 10mg olanzapine visa treatment zenker diverticulum. Although food ingestion can result in anaphylaxis buy olanzapine 10mg otc medicine effects, persistent asthma is not explained by food ingestion with IgE-mediated reactions discount olanzapine 5 mg with amex treatment 001. Nonallergic Asthma In nonallergic asthma, IgE-mediated airway reactions to common allergens are not present. Nonallergic asthma occurs at any age range, as does allergic asthma, but the former is generally more likely to occur in subjects with asthma younger than 4 years of age or older than 60 years of age. Episodes of nonallergic asthma are triggered by ongoing inflammation or by upper respiratory tract infections, purulent rhinitis, or sinusitis. In some patients, skin tests are positive, but despite the presence of IgE antibodies, there is no temporal relationship between exposure and symptoms. Often, but not exclusively, the onset of asthma occurs in the setting of a viral upper respiratory tract infection. Virus infections have been associated with mediator release and bronchial epithelial shedding, which could lead to ongoing inflammation and asthma symptoms. Chronic sinusitis can be identified in some patients with asthma, as can nasal polyps with or without aspirin sensitivity. Some experimental data exist on the presence of antiviral IgE antibodies and asthma ( 176). As our knowledge of mast cell activation grows, antiviral IgE antibodies or viral infection of lymphocytes causing cytokine production with triggering of asthma may be considered nonallergic. Indeed, the T H2 theory of asthma was supported in part by a study finding that protection against developing asthma in children aged 6 to 13 years was associated with day care attendance during the first 6 months of life or with having two or more older siblings at home ( 177). The protected children by age 13 years had a 5% incidence of asthma, compared with 10% in children who had not attended day care or who had 1 or no sibling ( 177). Of note is that at 2 years of age, the ultimately protected children had a 24% prevalence of wheezing, compared with 17% in nonprotected children. Allergen immunotherapy is not indicated and will not be beneficial in patients with nonallergic asthma despite any presence of antiallergen IgE antibodies. Mixed Asthma The term mixed asthma characterizes combined allergic and nonallergic triggers of asthma. These patients experience both classic IgE-mediated asthma and nonallergic asthma that may or may not be explained by recent viral upper respiratory tract infections, purulent rhinitis, or sinusitis. An example is a patient with grass- and ragweed-induced asthma, which in the particular geographic area is a recognized cause of asthma for 5 months of the year, but asthma is perennial. Potentially Fatal Asthma The term potentially fatal asthma refers to the patient who is at high risk for an asthma fatality ( 63,150). These patients have one of the following criteria: (a) respiratory acidosis or failure from asthma, (b) endotracheal intubation from asthma, (c) two or more episodes of status asthmaticus despite use of oral corticosteroids and other antiasthma medications, or (d) two or more episodes of pneumomediastinum or pneumothorax from asthma. Other factors have been associated with a potentially fatal outcome from asthma, and these criteria may not identify all high-risk patients ( 2). The physician managing the high-risk patient should be anticipating a potential fatality and trying to prevent this outcome ( 127). The impossible-to-manage (because of noncompliance) patient is said to have malignant, potentially fatal asthma (153). The onset of acute bronchoconstrictive symptoms after ingestion of such agents can be within minutes (such as after chewing Aspergum) to within 3 hours. In persistent asthma, variations in expiratory flow rates occur frequently, so that confirming that aspirin produces a reaction at 8 hours requires carefully controlled studies. With indomethacin, 1 mg or 5 mg oral challenges resulted in acute responses (180). Because fatalities have occurred in aspirin-sensitive subjects with asthma, challenges should be carried out only with appropriate explanation to the patient, with obvious need for the challenge (such as presence of rheumatoid arthritis), and by experienced physicians. Interestingly, some aspirin-sensitive patients can be desensitized to aspirin after experiencing early bronchospastic responses ( 180). Subsequent regular administration of aspirin does not cause acute bronchospastic responses ( 180). The aspirin triad refers to aspirin-sensitive patients with asthma who also have chronic nasal polyps ( 181). The onset of asthma often precedes the recognition of aspirin sensitivity by years. Contrary results in double-blind studies have been reported in that none of the patients responded to tartrazine ( 182). The risk for inadvertent exposure to tartrazine by the aspirin-sensitive patient appears to be smaller than initially reported and ranges from nonexistent ( 182) to 2. Structurally, these drugs are different but they have a common pharmacologic effect. Emerging evidence suggests that selective cyclooxygenase-2 inhibitors will be tolerated safely in aspirin-intolerant patients ( 187). None of 27 patients with aspirin-intolerant asthma developed acute bronchospasm during an incremental challenge protocol with celecoxib (10 mg, 30 mg, 100 mg every 2 hours on day 1 and 200 mg twice on day 2) (187). Similarly negative results have been found in 15 additional patients, 12 receiving celecoxib and 3 refecoxib ( 188). Occupational Asthma Occupational asthma has been estimated to occur in 5% to 15% of all patients with asthma ( 76,77 and 78). When it is IgE mediated, accumulating longitudinal data support a time of sensitization followed by development of bronchial hyperresponsiveness and then bronchoconstriction ( 76,189). After removal from the workplace exposure, the reverse sequence has been recorded. Malo and colleagues documented that spirometry and bronchial hyperresponsiveness in patients no longer working with snow crabs reached a plateau of improvement by 2 years after cessation of work exposure ( 189). In addition, one must differentiate true occupational asthma from exposed workers who have coincidental adult-onset asthma not affected by workplace exposure. Some workers have chemical exposure and a compensation syndrome, but no objective asthma despite symptoms and usually a poor response to medications. One must exclude work-related neuroses with fixation on an employer as well as a syndrome of reactive airways dysfunction, which occurs after an accidental exposure to a chemical irritant or toxic gas ( 190,191). Atopic status and smoking do not predict workers who will become ill to lower-molecular-weight chemicals. Atopic status and smoking are predictors of IgE-mediated occupational asthma to high-molecular-weight chemicals (76). For example, Western red cedar workers display bronchial hyperresponsiveness during times of exposure, with reductions in hyperresponsiveness during exposure-free periods. It is still undetermined whether anti plicatic acid IgE is necessary for development of Western red cedar asthma because immediate skin tests are negative and bronchial responses are present. An in vitro assay to detect IgE to plicatic acid human serum albumin demonstrated elevated antibodies to this conjugate in workers (192). The complexity of diagnosing occupational asthma cannot be underestimated in some workers. Respiratory symptoms may intensify when a worker returns from a vacation but may not be dramatic when deterioration occurs during successive days at work. In patients with preexisting asthma, fumes at work may cause an aggravation of asthma without having been the cause of asthma initially. Avoidance measures and temporary pharmacologic therapy can suffice to help confirm a diagnosis in some cases. Resumption of exposure should produce objective bronchial obstruction and clinical changes. The physician must be aware that workers may return serial peak expiratory flow rate measurements that coincide with expected abnormal values during work or shortly thereafter.
The mechanism by which this improvement occurs has not been definitely established cheap olanzapine 2.5mg online medications elavil side effects. However generic 10 mg olanzapine otc medicine rheumatoid arthritis, over the years order olanzapine 20mg without prescription medicine for pink eye, several mechanisms have been postulated to account for the improvement generic olanzapine 2.5 mg line medicine 6 clinic. Immunotherapy was first used by Noon and Freeman, who observed that pollen was the etiologic agent of seasonal rhinitis and that immunization was effective in the treatment of various infectious diseases, including tetanus and diphtheria. Cooke ( 29) observed that cutaneous reactivity was not obliterated by allergy injections. Cooke also discovered a serum factor, which he called blocking antibody, in the serum of patients receiving immunotherapy ( 30). This serum factor could inhibit the passive transfer of allergic antibody described by Prausnitz and Kstner. However, there was not a constant relationship between blocking antibody titers and symptom relief. The first controlled study of the efficacy of immunotherapy was published in 1949 ( 31). Within a short time in vitro techniques were developed to assess objectively the immunologic results of immunotherapy. Immunologic changes with immunotherapy In general, immunotherapy is indicated for clinically significant disease when the usual methods of avoidance and medication are inadequate to control symptoms ( 34) (Table 10. It is considered to be effective in ameliorating symptoms of allergic rhinitis, allergic asthma, and Hymenoptera sensitivity. Assessment of efficacy in these studies is difficult because the diseases being treated are chronic and have variations based on geography, climate, and individuals. Assessments are generally made from subjective daily symptom and medication reports by the patient. In some studies, objective clinical evaluation by physicians or by nasal or bronchial challenge was also a part of the assessment. In one study, children who were monosensitized to house dust mite and who received allergen immunotherapy developed fewer new sensitivities than those who did not receive immunotherapy ( 38). A metaanalysis of immunotherapy studies in asthma concluded that immunotherapy was efficacious ( 46). Examples of double-blind placebo-controlled allergen immunotherapy studies reporting efficacy There is no indication for immunotherapy in food allergy or chronic urticaria, nor is there sufficient evidence to support the use of bacterial vaccine ( 18,47). However, it is a potent allergen in the southern United States, where people often vacation. In the allergic evaluation, a patient undergoes skin testing with various allergens. For example, a patient having a positive grass skin test, rhinorrhea, and palatal itching in May and June in the Midwest will benefit from grass pollen immunotherapy. In contrast, a patient with an isolated positive grass skin test and with perennial symptoms of rhinorrhea and nasal congestion probably has vasomotor rhinitis and will not benefit from immunotherapy. Many patients have allergic rhinitis or allergic asthma from various types of animal dander. In rare instances, avoidance is unacceptable; for example, a blind person with a seeing-eye dog or a veterinarian whose livelihood depends on animal exposure cannot be expected to avoid these animals. Patients who are very sensitive to dander extracts may have difficulties with local or systemic reactions, such that it is difficult to attain clinically efficacious doses ( 50). Technical Aspects Allergen Extract Potency and Dosage Schedules The preparation and distribution of allergen extracts, also called vaccines, is regulated by the U. This agency has developed reference standards for a number of allergen vaccines and reference serum pools to be used by manufacturers to standardize their vaccines. Short ragweed and cat extracts (both hair and pelt) are standardized by major allergen content, unit per milliliter of Amb a 1 or unit per milliliter of Fel d 1, respectively. Other aeroallergen preparations made in the United States are not required to be standardized. Potency can be measured practically in various ways: cutaneous end-point titration, radioimmunoassay inhibition, or content of a known major allergen like antigen E ( Amb a 1) in ragweed, or Fel d 1 in cat extracts (51). Standard extracts, including short ragweed and Dermatophagoides pteronyssinus, have been developed by the Allergen Standardization Subcommittee of the International Union of Immunologic Societies ( 53,54). Until reference standards and exact quantitation of potency can be established for all extracts, less exact methods such as W/V will continue to be used. That is, a patient receiving immunotherapy to grass pollen and tree pollen could receive two injections, one of grass and one of tree, or could receive one injection containing both grass and tree pollens. Because mold extracts contain proteases that may influence other extracts like pollens and dust mite, some recommend giving mold as a separate injection (51). Most clinicians in the United States administer allergen immunotherapy subcutaneously, beginning with weekly or twice-weekly injections ( 55). Current evidence suggests that treatment with higher doses of pollen extracts results in better long-term reduction of clinical symptoms and greater immunologic changes than low-dose therapy. There is evidence that dosage based on the Rinkel technique, a low-dose protocol, is not effective ( 56). There are no clear data on the optimal length of time immunotherapy should be continued. Most patients who are maintained on immunotherapy and show improvement through three annual pollen seasons continue to maintain improvement even when their injections are discontinued ( 57). Patients who do not respond after receiving maintenance doses of immunotherapy for 1 year are unlikely to improve with further treatment. Therefore, immunotherapy should be discontinued in patients who have not had appreciable improvement after an entire year of maintenance doses. The most common method of administering perennial immunotherapy is subcutaneously using a dose schedule similar to that in Table 10. The injections are given weekly until the patient reaches the maintenance dose of 0. At that point, the interval between injections may be gradually increased to 2 weeks, 3 weeks, and ultimately monthly. When a new vial of extract is given to a patient receiving a maintenance dose of 0. There are patients whose achievable maintenance dose is lower than the standard shown in Table 10. Example of an allergy treatment tentative dosage schedule Other types of dosage schedules have also been published. In rush immunotherapy schedules, the starting doses are similar to those in Table 10. In cluster immunotherapy schedules, the initial dosages are similar to those in Table 10. The disadvantage of both cluster and rush regimens is that the reaction rate is probably somewhat higher than with more conventional schedules (58). For patients on those regimens, initial doses from new vials should also be reduced. Allergen extracts should be kept refrigerated at 4 C for retention of maximum potency. If a vial freezes or heats above 4 C, it should be discarded because the allergens may be altered. However, there is not sufficient evidence to support the use of this expensive technique instead of history and properly interpreted skin tests ( 60).
It has been reported that the epitopes discount olanzapine 7.5mg online medications online, which are recognized by neutralizing antibody olanzapine 2.5mg online medications similar to gabapentin, are located in the N-terminal function domain of rife-a ( 71) buy discount olanzapine 7.5mg medications covered by medicaid. Chronic granulomatous disease has been reported to be treated safely and effectively with rife-a ( 72) buy discount olanzapine 10mg online medicine just for cough. Follicle-stimulating Hormone With the increasing number of infertile couples deciding to pursue in vitro fertilization, the use of a variety of hormones has increased. There are other documented hypersensitivity reactions to urine-derived preparations while subsequently tolerating the recombinant protein ( 76). When that patient suffered another episode of hemorrhage, desensitization with pretreatment was attempted, but a moderately severe reaction occurred. Several investigators predicted that the incidence of inhibitors in patients treated only with the recombinant product would be higher ( 82,83). However, the studies suggest that the prevalence is about the same, with most patients having a low level of inhibitor that does not significantly affect the efficacy ( 84). Other Recombinant Proteins Hirudin is a thrombin inhibitor found in the salivary glands of leeches. In a trial of use of recombinant hirudin as an anticoagulant, an IgE-mediated hypersensitivity reaction was reported (85). A second risk of immunization is the possibility of reactions to vaccine components, such as eggs, gelatin, and neomycin. Finally, as happened with killed rubeola and respiratory syncytial virus vaccines, the protective immunity declined with time. When natural exposure resulted in infection, it was often atypical and actually more severe than in individuals who had never been immunized ( 91,92,93 and 94). Tetanus Toxoid Although minor reactions, such as local swelling, are common after tetanus toxoid or diphtheria-tetanus (dT) toxoid vaccinations, true IgE-mediated reactions are rare. However, the Institute of Medicine Report 1994 concluded that there was a causative relationship between anaphylaxis and administration of tetanus toxoid with or without diphtheria (95). A number of case reports have been published (96,97 and 98), but surveys estimate the risk for a systemic reaction to be very small, 0. Because diphtheria toxoid is not available as a single agent, it is impossible to separate the true incidence of diphtheria-associated reactions from those due to tetanus toxoid. When it appears necessary to administer tetanus toxoid to a patient with a history of a previous adverse reaction, a skin test graded challenge may be performed (100,101). One recommended approach is to begin with a skin-prick test using undiluted toxoid. After that, the balance of full-strength material may be given for a final total dose of 0. Pertussis and Rubella The Institute of Medicine analyzed adverse effects of pertussis and rubella vaccines ( 102). Encephalitis and other neurologic sequelae were once thought to be a consequence of pertussis vaccine, but the evidence does not report a causal association. Rubella vaccination results in arthritis and arthralgia in a significant percentage of adult and adolescent females. There are several reports that indicate that those reactions are due to another component, gelatin ( 104,105 and 106). Intradermal skin tests, following a negative prick skin test, are probably unnecessary and may be misleading. After a negative prick test, the vaccine may be administered in the routine fashion. Subsequently, at 15-minute intervals, increasing amounts of the undiluted vaccine (0. Using this protocol, systemic reactions have been reported; hence, a physician must be prepared to treat anaphylaxis (108). After completion of the procedure, it is advisable to keep the patient under observation for an additional 30 minutes. Influenza and Yellow Fever Vaccine in Egg-Allergic Patients Allergic reactions to influenza vaccine are rare, and the vaccine may be given safely to people who are able to tolerate eggs by ingestion, even if they demonstrate a positive skin test to egg protein ( 109). There is a report of 83 egg-allergic patients who received the influenza vaccine uneventfully, even though 4 had a positive prick test for the vaccine (110). The Advisory Committee on Immunization Practices does state that influenza vaccine should not be administered to people known to have anaphylactic hypersensitivity to eggs or other components of the vaccine without first consulting a physician (111). Among asthmatic patients, there was some concern about inducing bronchospasm after administration; however, there appears to be no evidence of asthmagenicity after influenza vaccine ( 112). Clearly, the patient with moderate-to-severe asthma is at risk from natural infection and will benefit from influenza vaccination. Although yellow fever vaccine is not required in the United States, travelers to endemic areas may require immunization. In another study, two of 493 individuals with a positive history of egg allergy had anaphylaxis following yellow fever immunization; both of these patents had positive skin tests to both egg and the vaccine ( 114). The Centers for Disease Control and Prevention lists egg hypersensitivity as one of the reasons that an individual should not receive yellow fever vaccine. It is suggested that the individual obtain a waiver letter from a consular or embassy official ( 115). For patients with a clear history of egg allergy or when in doubt, skin testing with the appropriate vaccine is a reliable method to identify the patients at risk ( 111). A prick test is performed with a 1:10 dilution of the vaccine in normal saline, and a normal saline control. After a positive skin test to the vaccine, if it is considered essential, administer 0. Other Vaccines Both typhoid and paratyphoid vaccines have been reported to cause anaphylaxis ( 117,118). In a study of 14,249 marines who received Japanese encephalitis vaccine, the reaction rate was 0. In a study of 1,198,751 individuals who received meningococcal vaccine, the rate of anaphylaxis was reported as 0. Because varicella vaccine contains neomycin, individuals with neomycin hypersensitivity would be at potential risk for an allergic reaction ( 121). There are several case reports of anaphylactic episodes after hepatitis B vaccine (122,123). Until 1999, the only hepatitis B vaccines available contained thimerosal, making them difficult to administer to individuals with thimerosal allergy (124). Introducing MedWatch: a new approach to reporting and device adverse effects and product problems. The prevention of immediate generalized reactions to radiocontrast media in high risk patients. Immunologic mechanisms of penicillin allergy: a haptenic model system for the study of allergic diseases in man. Classification of allergic reactions responsible for clinical hypersensitivity and disease. The role of a documented allergic profile as a risk factor for radiographic contrast media reactions. Relationship of acetyltransferase activity to antinuclear antibodies and toxic symptoms in hypertensive patients treated with hydralazine. Effect of acetylator phenotype on the rate at which procainamide induces antinuclear antibodies and the lupus syndrome. Diagnosis of sulfonamide hypersensitivity reactions by in vitro rechallenge with hydroxylamine metabolites. Allergic reactions to antimicrobial drugs in patients with a history of prior drug allergy. Sensitization to aztreonam and cross-reactivity with other beta-lactam antibiotics in high-risk patients with cystic fibrosis.
Recent studies of human IgE and IgG to sulfonamides have established the N -sulfonamidoyl determinant to be the major sulfonamide haptenic determinant (30) olanzapine 7.5mg sale symptoms dust mites. It should be noted that an antigen must have multiple combining sites (multivalent) to elicit hypersensitivity reactions olanzapine 7.5 mg without prescription medications epilepsy. This requirement permits bridging of IgE and IgG antibody molecules or antigen receptors on lymphocytes order 20mg olanzapine otc medicine quotes doctor. Conjugation of the free drug or metabolite (hapten) with a macromolecular carrier to form a multivalent hapten-carrier conjugate is necessary to initiate an immune response and elicit a hypersensitivity reaction discount olanzapine 7.5mg with visa medications going generic in 2016. The univalent ligand (free drug or metabolite), in large excess, may inhibit the response by competing with the multivalent conjugates for the same receptors. Therefore, the relative concentration of each will determine the frequency, severity, and rate of allergic drug reactions. Also, removal of haptens from carrier molecules by plasma enzymes (dehaptenation) will influence the likelihood of such reactions ( 31). Finally, some low-molecular-weight drugs, such as quaternary ammonium muscle relaxants and aminoglycosides, have enough distance between determinants to act as bivalent antigens without requiring conjugation to a carrier ( 32). Immunologic Response to Drugs Drugs often induce an immune response, but only a small number of patients actually experience clinical hypersensitivity reactions. For example, most patients exposed to penicillin and insulin develop demonstrable antibodies; however, in most instances, these do not result in allergic reactions or reduced effectiveness of the drug. Mechanisms of Drug-Induced Immunopathology An immunologic response to any antigen may be quite diverse and the attendant reactions quite complex. Drugs are no exception and have been associated with all of the immunologic reactions proposed by Gell and Coombs ( 33) subsequently modified by Kay (34) and Janeway (35). It is likely that more than one mechanism may contribute to a particular reaction, but often one will predominate. Immunopathology of allergic reactions to drugs Penicillin alone has been associated with many of these reactions. Anaphylaxis and urticaria following penicillin administration are examples of type I reactions. Risk factors for drug allergy Drug- and Treatment-related Factors Nature of the Drug Macromolecular drugs, such as heterologous antisera and insulin, are complex antigens and have the potential to sensitize any patient. As noted earlier, most drugs have molecular weights of less than 1,000 daltons and are not immunogenic by themselves. Immunogenicity is determined by the potential of the drug or, more often, a drug metabolite to form conjugates with carrier proteins. Drug Exposure Cutaneous application of a drug is generally considered to be associated with the greatest risk for sensitizing patients ( 37). In fact, penicillin, sulfonamides, and antihistamines are no longer used topically because of this potential. The adjuvant effect of some intramuscular preparations may increase the risk for sensitization; for example, the incidence of reactions to benzathine penicillin is higher than other penicillin preparations. Once a patient is sensitized, the difference in reaction rates between oral and parenteral drug administration is likely related to the rate of drug administration. Anaphylaxis is less common after oral administration of a drug, although severe reactions have occurred. For other allergic drug reactions, the evidence supporting oral administration is less clear. The dose and duration of treatment appear to affect the development of a drug-specific immunologic response. Penicillin-induced hemolytic anemia follows high, sustained levels of drug therapy. There is currently little evidence that the frequency of drug administration affects the likelihood of sensitization ( 37). However, frequent courses of treatment are more likely to elicit an allergic reaction as is interrupted therapy. Patient-related Factors Age and Gender There is a general impression that children are less likely to become sensitized to drugs than adults. Some confusion may arise in that the rash associated with a viral illness in children may incorrectly be ascribed to an antibiotic being administered as treatment. Genetic Factors Allergic drug reactions occur in only a small percentage of individuals treated with a given drug. It is likely that many factors, both genetic and environmental, are involved in determining which individuals in a large random population will develop an allergic reaction to a given drug. Patients with a history of allergic rhinitis, asthma, or atopic dermatitis ( the atopic constitution) are not at increased risk for being sensitized to drugs compared with the general population (37). Among adolescents whose parents had sustained an allergic reaction to antibiotics, 25. Prior Drug Reactions Undoubtedly, the most important risk factor is a history of a prior hypersensitivity reaction to a drug being considered for treatment or one that may be immunochemically similar. Ten years after an immediate-type reaction to penicillin, only about 20% of individuals are still skin test positive. The likelihood of cross-reactivity among the various sulfonamide groups (antibacterials, sulfonylureas, diuretics) is an issue that has not been resolved. There is little supporting evidence in the medical literature that cross-sensitization is a significant problem. Patients who have demonstrated drug hypersensitivity in the past appear to have an increased tendency to develop sensitivity to new drugs. Penicillin-allergic patients have about a 10-fold increased risk for an allergic reaction to non b-lactam antimicrobial drugs ( 45,46). With the exception of the aminoglycosides, reaction rates were much higher than expected in all other antibiotic classes, including erythromycin. Among children with multiple antibiotic sensitivities by history, 26% had positive penicillin skin tests ( 47). These observations suggest that such patients are prone to react to haptenating drugs during an infection ( 48). Concurrent Medical Illness Although atopy does not predispose to the development of IgE-mediated drug hypersensitivity, it appears to be a risk factor for more severe reactions once sensitivity has occurred, especially in asthmatic patients ( 36,37). Children with cystic fibrosis are more likely to experience allergic drug reactions, especially during drug desensitization (49). Maculopapular rashes following the administration of ampicillin occur more frequently during Epstein-Barr viral infections and among patients with lymphatic leukemia (50). Immune deficiency is associated with an increased frequency of adverse drug reactions, many of which appear to be allergic in nature. Patients who are immunosuppressed may become deficient in suppressor T lymphocytes that regulate IgE antibody synthesis. Concurrent Medical Therapy Some medications may alter the risk and severity of reactions to drugs. Clinical classification of allergic reactions to drugs What follows is a brief discussion of each of these clinical entities, including a list of most commonly implicated drugs. Detailed lists of implicated drugs appear in periodic literature reviews ( 55,56). Generalized or Multisystem Involvement Immediate Generalized Reactions The acute systemic reactions are among the most urgent of drug-related events. Greenberger has used the term immediate generalized reactions to underscore the fact that many are not IgE mediated (57). Drug-induced anaphylaxis should be reserved for a systemic reaction proved to be IgE mediated.