Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0042109 (urticaria)
 6,569 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Angioedema without urticaria is a clinical syndrome characterised by self-limiting local swellings involving the deeper cutaneous and mucosa tissue layers. Most occurrences of angioedema respond to treatment with a histamine H1 receptor blocker (antihistamine) because they are an allergic or parallergic reaction. A small number of cases do not respond to antihistamine treatment. Such cases tend to occur in patients with deficiency or dysfunction of the inhibitor of the first component of the complement (C1-INH), but more rarely can occur in patients with other conditions and as an adverse drug reaction. Angioedema is well documented in patients taking ACE inhibitors. Considering that 35 to 40 million patients are treated worldwide with ACE inhibitors, this drug class could account for several hundred deaths per year from laryngeal oedema. ACE inhibitors certainly do not mediate angioedema through an allergic or idiosyncratic reaction. For this reason the relationship with this drug is often missed and consequently quite underestimated. Rare instances of angioedema have also been reported with angiotensin II receptor antagonists. This adverse effect seems to occur less frequently with angiotensin II receptor antagonists than with ACE inhibitors. However, we do not know whether this adverse effect has the same mechanism with the 2 classes of medications. Some cases of severe angioedema have been recently reported after treatment with fibrinolytic agents. Scattered reports suggest the possibility of angioedema associated with the use of estrogens, antihypertensive drugs other than ACE inhibitors, and psychotropic drugs. Angioedema can also occur with nonsteroidal anti-inflammatory drugs. Prevention of angioedema relies first on the patient history. Estrogen and ACE inhibitors should be avoided in a patient with congenital or acquired C1-INH deficiency. In the case of ACE inhibitors, the appearance of angioedema following long term treatment does not lessen the probability that such an agent could be the cause. The most important action to take in a patient with suspected drug-induced angioedema is to discontinue the pharmacological agent. Epinephrine (adrenaline), diphenydramine and intravenous methylprednisolone have been proposed for the medical management of airway obstruction, but so far no controlled studies have demonstrated their efficacy. If the acute airway obstruction leads to life-threatening respiratory compromise an emergency cricothyroidotomy must be performed.
 ...
PMID:Drug-induced angioedema without urticaria. 1148 Apr 92

Beta-lactams are the antibiotics which most frequently provoke adverse reactions mediated by specific immunological mechanisms. These reactions, classifiable as immediate or non-immediate, can be produced by the four classes of beta-lactams (penicillins, cephalosporins, carbapenems and monobactams) currently available, which share a common beta-lactam ring structure. Immediate reactions occur within the first hour after drug administration and are characterized by urticaria, angioedema, rhinitis, bronchospasm, and anaphylactic shock. Immediate reading skin tests are the quickest and most reliable method for demonstrating the presence of beta-lactam specific IgE antibodies. It is crucial to use in diagnosis the suspected beta-lactams themselves, particularly cephalosporins, in addition to penicillin determinants. Serum specific IgE assays can be used as complementary tests. Negative test results should be interpreted in light of the time elapsed from the last exposure to the responsible beta-lactam. In fact, both in vivo and in vitro test sensitivity is known to decrease over time. In some diagnostic work-ups, patients with a positive history and negative skin and in vitro tests with classic reagents undergo a controlled administration of the suspected beta-lactam. The management of immediate allergic reactions should take into consideration their severity and type. Adrenaline is the drug of choice in the treatment of anaphylactic shock. In addition to adrenaline, corticosteroids and antihistamines should be administered. Histamine H(1) receptor antagonists are the mainstay of the treatment of immediate allergic reactions such as urticaria, rhinitis and conjunctivitis.
 ...
PMID:Immediate allergic reactions to beta-lactams: diagnosis and therapy. 1257 27

This was a great save. The crew could easily have missed the presentation of anaphylaxis and let the window for treatment with epinephrine slip away. This patient was in anaphylactic shock. There were no signs that supported a traumatic injury, and that, combined with diaphoresis, urticaria and tachycardic central pulse, contributed to the suspicion of anaphylaxis. Anaphylaxis is classified as distributive shock. This type of shock is caused by profound systemic vasodilation, and the heart is unable to increase output enough to maintain blood pressure. Other causes of distributive shock include sepsis and spinal cord injury. It is rare to have both hypotension and wheezing in such cases. In an anaphylactic reaction, an allergen, such as a food protein, medication, insect venom or latex, is introduced into the body. The mast cells of the immune system have a protein on their surface called IgE antibodies (Immunoglobulin E). The mast cells are filled with histamines [table: see text] and leukotrienes, which are chemical mediators. These are released when the allergen reacts with the IgE antibodies. When these mediators are released, they cause smooth-muscle constriction in the respiratory and gastrointestinal tracts, resulting in wheezing, stridor, nausea, vomiting and diarrhea. They also cause vascular dilation, leading to edema and urticaria. Most patients will present with either profound vascular effect (shock) or wheezing; this is a rather rare presentation of a patient having both. The medication best suited to counteract the effects of these medicators is epinephrine. Epinephrine is an alpha- and beta-agonist, acting to constrict the vasculature and dilate the smooth muscles in the bronchial tree. Antihistamines can alleviate symptoms of anaphylaxis, but should only be used in addition to epinephrine, not as a substitute. In life-threatening reactions, epinephrine must be given quickly and in a form that the body can distribute. Use of the subcutaneous route with a solution mixed at 1:1,000 dilution is appropriate in most patients, but if the patient is in profound shock and not perfusing the skin (pale, cold, clammy skin), then a more diluted concentration must be given i.v. at a slow rate (1 cc every minute of the 1:1,000 dilution) until the patient recovers. If i.v. access is delayed or not available, give the 1:1,000 dilution intramuscularly, in the tongue or down the endotracheal tube. Refer to your local protocols for dosage, but the usual dose of epinephrine is 0.3-0.5 mg, or 0.01 mg/kg in a child. There are more than 40 million people in the U.S. with allergic histories that place them at risk for developing anaphylaxis. Each year over 5,000 deaths are attributed to anaphylaxis. The risk of death from anaphylaxis increases with a more rapid onset of signs and symptoms. Up to 25% of patients will experience a biphasic reaction. This means there is a recurrence of symptoms several hours after the initial reaction, and it is prudent to observe patients for a period of time following their initial treatment.
 ...
PMID:Bugged. 1277 12

Systemic allergic reactions to insect stings are estimated to occur in about 1 percent of children and 3 percent of adults. In children, these reactions usually are limited to cutaneous signs, with urticaria and angioedema; adults more commonly have airway obstruction or hypotension. Epinephrine is the treatment of choice for acute anaphylaxis, and self-injection devices should be prescribed to patients at risk for this allergic reaction. Stinging insect allergy can be confirmed by measurement of venom-specific IgE antibodies using venom skin tests or a radioallergosorbent test. Patients with previous large local reactions have a 5 to 10 percent risk of experiencing systemic reactions to future stings. Patients with previous systemic reactions have a variable risk of future reactions: the risk is as low as 10 to 15 percent in those with the mildest reactions and in some children, but as high as 70 percent in adults with the most severe recent reactions. Because of demonstrated efficacy (98 percent), venom immunotherapy is recommended for use in patients who are at risk for severe systemic reactions to future insect stings. Venom immunotherapy is administered every four to eight weeks for at least five years. Immunotherapy may be needed indefinitely in patients at higher risk for recurrence of anaphylaxis after treatment is stopped.
 ...
PMID:Stinging insect allergy. 1282 43

The tissues affected by histamine and anaphylactic reactions are identical. Epinephrine antagonizes the action of histamine by acting on effector cells in a direction opposite to that of histamine. The so-called antihistaminic drugs block rather than antagonize the action of histamine. The injection into the human body of epinephrine or certain antihistaminic substances provokes the release of histamine and thereby produces a rise in the histamine blood level. There is a remarkable conformity of potency of antihistaminics as determined by Dale experiments and by histamine intoxication experiments in the intact guinea pig. Neoantergan, Pyribenzamine and Histadyl are usually superior to other compounds when potency is assayed by these methods. All antihistaminics provide similar protection again animal anaphylaxis. Larger doses are necessary to protect against anaphylaxis than against histamine intoxication. The differences in potency as determined by Dale experiments and histamine experiments in animals are not found in clinical use. One compound is not generally superior to all others in the treatment of any one or several allergic disorders. The antihistaminic drugs are beneficial in the symptomatic treatment of allergic rhinitis, acute urticaria and angioneurotic edema, and mild non-infective bronchial asthma. Their effectiveness in the management of moderately severe and severe non-infective bronchial bronchial asthma; infective bronchial asthma; migraine; atopic dermatitis (disseminated neurodermatitis), and pruritus of skin disorders other than acute urticaria and angioneurotic edema, is not worthy of particular commendation. The size of the dose of any antihistaminic substance influences the incidence of but not the type of side-effect that may accompany its usage. The quality of side effects varies according to the drug, although there is an individuality of response for each patient which must be reckoned with. In selecting an antihistaminic compound it is necessary to consider the percentage of cases in which side effects occur, as well as the percentage of good results. Optimal results are obtained by employing combinations of compounds and changing from one to the other as the case demands.
 ...
PMID:Histamine and the antihistaminic drugs. 1541 37

Epinephrine is the only definitive treatment of anaphylaxis, and recent evidence suggests that the intramuscular route has superior pharmacokinetics to subcutaneous administration. There is little data regarding what route is commonly used in clinical practice. The objective of this article is to determine the rate of epinephrine use in cases of anaphylaxis and route of administration utilized. A retrospective review was made of 220 medical records with the primary diagnosis of urticaria, angioedema, or anaphylaxis over a 28-month period at a military medical center. Twenty-four cases of anaphylaxis identified in the records. Demographics, along with signs and symptoms of those experiencing anaphylaxis, were similar to other published reports. Epinephrine was given in only 50% of cases and largely by the subcutaneous route. No intramuscular epinephrine was administered. H1 blockers and steroids were the most commonly administered treatments. H2 blockers were given at the same rate as epinephrine. An autoinjector was prescribed in 29% of cases with instruction on its use documented in 13%. An allergy referral was made in 29% of cases. Greater educational efforts and collaboration are needed between the allergy community and other providers regarding the importance of administering epinephrine intramuscularly, prescribing autoinjectors, and referring to an allergist in cases of anaphylaxis.
 ...
PMID:Anaphylaxis and epinephrine prescribing patterns in a military hospital: underutilization of the intramuscular route. 1645 May 70

Methylene blue has multiple indications for use, but recently it has been shown to be useful in treating refractory hypotension. Anaphylaxis results in widespread vasodilation and hypotension. Epinephrine has been described as the drug of choice in the treatment of hypotension for anaphylaxis, but the increased heart rate may be poorly tolerated by some patients. This case report describes a 79-year-old man with a history of diastolic dysfunction who was admitted for elective coronary artery bypass graft surgery. After induction of general anesthesia, symptoms of anaphylaxis developed with urticaria and decreased mean arterial pressure. The hypotension was refractory to vasoactive agents and volume repletion. Methylene blue was primed in the cardiopulmonary bypass pump and was effective in restoring hemodynamic stability. Furthermore, the patient required a decreased amount of vasoactive agents in the postoperative course. The suspected mechanism of action of methylene blue is inhibition of the enzyme nitric oxide synthase, which ultimately prevents the smooth muscle dilation that accompanies anaphylaxis. Methylene blue may be a valuable adjunct in the treatment of anaphylaxis and other causes of refractory hypotension.
 ...
PMID:Methylene blue for refractory hypotension: a case report. 1877 11

Perioperative anaphylaxis is a life-threatening condition with an estimated prevalence of 1:3,500 to 1:20,000 procedures and a mortality rate of up to 9 %. Clinical presentation involves signs such as skin rash, urticaria, angioedema, bronchospasm, tachycardia, bradycardia, and hypotension. Prompt recognition and treatment is of utmost importance to the patient's prognosis, since clinical deterioration can develop rapidly. Epinephrine is the main treatment drug, and its use should not be postponed, since delayed administration is associated with increased mortality. Elevated levels of serum tryptase help to confirm the diagnosis. The main agents involved in IgE-mediated perioperative anaphylaxis are neuromuscular blocking agents, latex, antibiotics, hypnotics, opioids, and colloids. Specific investigation should be conducted 4 to 6 weeks after the reaction and relies on skin tests, serum-specific IgE, and challenge procedures. This review aims to discuss the main aspects of perioperative anaphylaxis: risk factors, diagnosis, treatment, culprit agents, specific investigation, and preventive measures.
 ...
PMID:Perioperative anaphylaxis. 2495 Dec 38

IgE-mediated food allergy is an important health concern with increasing prevalence worldwide. Manifestations of IgE-mediated food allergy include urticaria, angioedema, pruritus, difficulty in breathing, laryngeal oedema, vomiting, diarrhoea and/or hypotension within minutes to two hours of the offending food's ingestion. Diagnosis requires both a careful history and supportive testing with laboratory studies and possibly oral food challenges. Current treatment of food allergy focuses on avoidance of the allergen and prompt emergency management of reactions. Epinephrine autoinjectors are provided to patients for the treatment of severe reactions. More research is needed to determine the optimal timing with which to introduce common allergens into a child's diet to possibly prevent the development of food allergy. Novel therapies are under investigation given the difficulty of allergen avoidance and the potentially fatal nature of reactions. Both allergen specific therapies such as oral, sublingual and epicutaneous immunotherapy and allergen non-specific therapies such the Chinese herbal formula FAHF-2 and omalizumab show promise though more data on efficacy and long-term safety are needed before these therapies become mainstream.
...
PMID:Food allergy: diagnosis, management & emerging therapies. 2510 14

In this rostrum we aim to increase awareness of anaphylaxis in infancy in order to improve clinical diagnosis, management, and prevention of recurrences. Anaphylaxis is increasingly reported in this age group. Foods are the most common triggers. Presentation typically involves the skin (generalized urticaria), the respiratory tract (cough, wheeze, stridor, and dyspnea), and/or the gastrointestinal tract (persistent vomiting). Tryptase levels are seldom increased because of infant anaphylaxis, although baseline tryptase levels can be increased in the first few months of life, reflecting mast cell burden in the developing immune system. The differential diagnosis of infant anaphylaxis includes consideration of age-unique entities, such as food protein-induced enterocolitis syndrome with acute presentation. Epinephrine (adrenaline) treatment is underused in health care and community settings. No epinephrine autoinjectors contain an optimal dose for infants weighing 10 kg or less. After treatment of an anaphylactic episode, follow-up with a physician, preferably an allergy/immunology specialist, is important for confirmation of anaphylaxis triggers and prevention of recurrences through avoidance of confirmed specific triggers. Natural desensitization to milk and egg can occur. Future research should include validation of the clinical criteria for anaphylaxis diagnosis in infants, prospective longitudinal monitoring of baseline serum tryptase levels in healthy and atopic infants during the first year of life, studies of infant comorbidities and cofactors that increase the risk of severe anaphylaxis, development of autoinjectors containing a 0.1-mg epinephrine dose suitable for infants, and inclusion of infants in prospective studies of immune modulation to prevent anaphylaxis recurrences.
 ...
PMID:Anaphylaxis: Unique aspects of clinical diagnosis and management in infants (birth to age 2 years). 2544 36


1