Do air cleaners make a difference in treating allergic disease in homes?

LEARNING OBJECTIVES: The purpose of this review is to objectively critique available data regarding the clinical benefits of room air cleaners and to provide physicians and patients with a reasonable recommendation of their utility in treatment of inhalant allergic disease. DATE SOURCES: Data were obtained from published studies and reviews. STUDY SELECTION: The specific reviewed studies met the following criteria: 1) selection of patients with clinical allergic disease confirmed by detection of allergen-specific immunoglobulin E; 2) use of an effective air filter; 3) clinical and laboratory evaluation of results; and 4) measurement of the results of air filtration on environmental allergen or airborne particulate levels. The studies were conducted in a double-blind manner. Conclusions of two previous reviews are also incorporated in this paper. RESULTS: The results of the published studies and summary reviews show minimal, if any, effectiveness of room air cleaners in treatment of allergic respiratory disease. CONCLUSIONS: Room air cleaners should not be recommended for people with inhalant allergic disease.

Hot dog vapor-induced status asthmaticus.

BACKGROUND: Asthma induced by the inhalation of food vapors is unusual and indicative of extreme allergy. Identification of the specific cause and subsequent avoidance is essential. METHODS: We report a patient with asthma who had status asthmaticus following inhalation of boiling hot dog vapors. Prick skin tests were performed to various ingredients of the offending hot dog including chicken, pork, potato, and the aeroallergens. RESULTS: Prick skin tests reacted strongly to chicken and mildly to pork and potato. There was no reaction to aeroallergens. Our patient has not had any acute asthma after avoiding eating and exposure to chicken and hot dog vapors. CONCLUSIONS: Exquisite allergy to chicken was responsible for acute asthma.

Risk of administering cephalosporin antibiotics to patients with histories of penicillin allergy.

OBJECTIVES: The purpose of this review was to analyze available relevant data regarding the safety of administering cephalosporins to penicillin-allergic patients, including the significance of penicillin skin test reactions and any difference related to first, second, or third generation cephalosporins. BACKGROUND: Penicillin and cephalosporins both contain a beta-lactam ring. This structural similarity has led to considerable confusion about the cross-allergenicity of these drugs and the risks of allergic reactions from cephalosporins in penicillin-allergic patients. METHODS: Published reports and post-marketing data from pharmaceutical corporations provided the basis for this analysis. RESULTS: The overall incidence of adverse reactions from cephalosporins ranges from 1% to 10%, with rare anaphylaxis (< 0.02%). In patients with histories of penicillin allergy the incidence of cephalosporin reactions is minimally, if at all increased. Post-marketing studies of second and third generation cephalosporins showed no increase in allergic reactions in patients with penicillin allergy histories. Penicillin skin tests do not predict the likelihood of allergic reactions to cephalosporins in patients with histories of penicillin allergy. One reaction occurred in 98 patients (1%) with positive penicillin skin tests and six reactions occurred in 310 patients (2%) with negative tests. CONCLUSIONS: These data indicate that it is safe to administer cephalosporin antibiotics to penicillin-allergic patients and penicillin skin tests do not identify potential reactors.

Vancomycin anaphylaxis and successful desensitization.

This report describes vancomycin anaphylaxis and successful desensitization. A 35-year-old woman who tolerated vancomycin initially, developed generalized urticaria and respiratory distress when the drug was readministered. Symptoms recurred following infusion of vancomycin at a lowered rate and dose despite premedication with antihistamines and corticosteroids. Intradermal skin tests with vancomycin were positive at a concentration of 0.1 micrograms/mL. Control subjects reacted at a concentration of 10 micrograms/mL or greater. A rapid 1-day desensitization protocol was unsuccessful. The patient then was "desensitized" by sequential increments in intravenous vancomycin doses over 13 days. After the full therapeutic dose was tolerated, there was a loss of skin test reactivity to vancomycin. We conclude that desensitization to vancomycin is possible and may be the only means to treat an allergic patient adequately when there are no viable therapeutic alternatives.

Duration of venom immunotherapy: relationship to the severity of symptoms of initial insect sting anaphylaxis.

BACKGROUND: This study assessed the postulate that the adequate duration of venom immunotherapy (VIT) is related to the severity of the initial sting anaphylactic symptoms. METHODS: Data were collected from patients with venom allergy who had sting anaphylaxis and subsequent positive venom skin test results, received maintenance VIT, and had field re-stings after cessation of VIT. There were 217 re-stings in 113 patients with 15 systemic reactions in 10 patients (a re-sting reaction rate of 9% per sting and 7% per patient). RESULTS: Re-sting reactions occurred in 1 of 25 patients with initial mild anaphylaxis (4%), 2 of 41 patients with moderate reactions (5%), and 7 of 47 patients with initial severe symptoms (15%). The results were not influenced by the duration of VIT or the interval between cessation of VIT and the re-sting. Eighteen patients who converted to negative skin test reactions had no reactions when re-stung. CONCLUSIONS: These results suggest a relationship between the severity of anaphylaxis and subsequent duration of VIT. Two to three years is sufficient for patients who had mild to moderate anaphylaxis. Longer duration of therapy is advisable for patients who had severe symptoms and continue to have positive venom skin test results.

Natural history of insect sting allergy: relationship of severity of symptoms of initial sting anaphylaxis to re-sting reactions.

To examine the postulate that the nature of the symptoms of initial insect sting anaphylaxis is related to the risk and severity of subsequent sting reactions, the results of field re-stings were analyzed in 220 patients who had had venom anaphylaxis and did not receive venom immunotherapy. The incidence of a reaction after the first re-sting was 56% in the total group, was more frequent in adults (74%) than in children (40%), and was unrelated to the time interval since the initial sting reaction. When re-sting reactions did occur, the nature of the symptoms was similar to the symptoms of the initial sting reaction. Reactions to repeated re-stings tended to be similar. Overall, more severe reactions to re-stings occurred eventually in 24 patients. These observations confirm the frequent self-limiting course of insect sting allergy, especially in children, and the repetitive nature of specific anaphylactic symptoms, and the observations thus suggest that patients with mild to moderate anaphylactic symptoms probably do not require venom immunotherapy.

Stinging insect allergy.

Insect sting anaphylaxis is a relatively common problem estimated to affect at least 0.4% of the population and is responsible for at least 40 deaths per year in the United States. The allergic reactions are mediated by IgE antibodies directed at constituents in honeybee, yellow jacket, hornet, and wasp venoms. In addition, increasing numbers of reactions occur from fire ant stings, non-winged Hymenoptera present in the Southeastern United States. The anaphylactic symptoms are typical of those occurring from any cause. Most reactions in children are mild, frequently involving dermal manifestations (hives, edema) only. The more severe reactions, such as shock and loss of consciousness, can occur at any age but are relatively more common in adults. Following sting anaphylaxis, approximately 50% of unselected patients will continue to have allergic reactions to subsequent stings. The natural history of the disease process is influenced by the severity of the anaphylactic symptoms. Children with dermal reactions only have a benign course and are unlikely to have recurrent reactions. Patients with more severe reactions are at risk for repeat anaphylaxis. Patients with a history of insect sting anaphylaxis and positive venom skin tests should have epinephrine available and are candidates for subsequent venom immunotherapy, which provides almost 100% protection against subsequent re-sting reactions. Recommendations for the duration of immunotherapy are evolving. Venom therapy can be stopped if skin test reactions become negative. For most patients, 3 years of therapy appears adequate, despite persistence of positive venom skin tests.

Venom immunotherapy: 10 years of experience with administration of single venoms and 50 micrograms maintenance doses.

For the past 10 years, we have administered venom immunotherapy with single venoms, whenever it is possible, and maintenance doses of 50 micrograms. The choice of venoms was based on clinical history, skin test reactions, and a knowledge of venom cross-reactivity. There have been 258 re-stings in 108 patients with only three systemic reactions (2.7% per patient; 1.2% per sting). Two of these re-stings reactions were very mild, hives and facial edema, in patients who had had initial severe anaphylaxis. Five other patients had transient ill-defined symptoms, not considered allergic after re-stings. The patients covered a wide age range. Twenty-seven patients, nine under age 16 years, had initial dermal reactions only, and 44 patients had severe anaphylaxis. Most patients had multiple positive skin tests. Seventy-five patients received single venoms (yellow jacket, 58; honeybee, 15; hornet, 2), and 30 patients received two venoms. Re-stings occurred from 1 month to 8 years, (mean, 2 years) after starting treatment. Results indicate that this approach with 50 micrograms top doses and single venom immunotherapy may be sufficient in most patients with an associated decrease in the cost as well as possible increased morbidity associated with the use of multiple venom antigens.

Unusual reactions to insect venoms.

A variety of unusual, unexpected reactions have been described that occur in a temporal relationship to venom exposure, primarily insect stings. An immunologic mechanism appears responsible for reactions such as serum sickness and late onset allergiclike symptoms. In all probability, allergic mechanisms are responsible for the renal and neurologic symptoms and the delayed hypersensitivity type reactions. The mechanisms for the fatigue and malaise following venom injections and the most unusual areas of extensive erythema following venom skin tests are not known.