Active — Not RecruitingNot Applicable

Cause of Unexplained Anaphylaxis

United States115 participantsStarted 2008-11-05

Plain-language summary

This study will explore the possible cause of unexplained, or idiopathic, anaphylaxis. Anaphylaxis is a rapid, life-threatening, severe reaction that occurs suddenly after contact with an allergy-causing substance, usually a particular food, drug or stinging insect. The allergen triggers mast cells to release several substances, including histamine. Histamine is responsible for many of the symptoms that may occur, such as flushing, hives, swelling of the palms and soles or tongue and vocal cords, nasal congestion, itching and tearing of the eyes, shortness of breath and wheezing, stomach pain, vomiting, low blood pressure, loss of consciousness, shock, and, rarely, death. Severe episodes of anaphylaxis are treated with epinephrine (adrenaline), followed by oral antihistamines and steroids. In more than half of cases of anaphylaxis, a clear cause is not identified. These cases are called idiopathic anaphylaxis. There is no cure or long-term preventive therapy for patients with recurrent episodes of idiopathic anaphylaxis. People between 13 and 70 years of age who have idiopathic anaphylaxis, or have anaphylaxis that is caused by specific allergens such as food, venom, or drugs and medications may be eligible for this study. Participants are evaluated at the NIH Clinical Center with the following tests and procedures: * Medical history, physical examination and blood tests. * Bone marrow biopsy. For this test, the skin over the hipbone and the outer surface of the hipbone itself are numbed with local anesthesia. Then, a needle is inserted into the hipbone and a small amount of bone marrow is drawn into a syringe. The needle also cuts a small core of bone marrow, which is removed for analysis. * Other tests that may be needed for evaluation of the patient s condition.

Who can participate

Age range13 Years – 75 Years

SexALL

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AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

* INCLUSION CRITERIA: * Subjects must be at least 13 years of age and no older than 75 years of age. * Subjects with IA must have a diagnosis of anaphylaxis occurring in the absence of an identifiable provoking agent or stimulus by a referral provider. Patient may carry both the diagnosis of 1A and the diagnosis of SA. * Subjects with SA must have a history of a severe reaction to a venom, food or, drug confirmed when possible by relevant skin testing, challenge testing, RAST, immunoCAP, or ELISA. within the past 36 months. * Subject must have had a doctor s office or ER visit, or a hospitalization for evaluation for anaphylaxis and have a history of involvement of the skin and/or mucosal tissue (e.g., flushing, itching, hives, angioedema, tongue swelling), and at least one of the following: * Respiratory compromise (e.g., dyspnea, hoarseness-laryngeal edema, wheeze-bronchospasm, stridor, reduced peak expiratory flow, hypoxemia). * Gastrointestinal symptoms of vomiting and/or diarrhea * Reduced blood pressure and/or associated symptoms of end-organ dysfunction (as evidenced hypotonia, hypoxia, collapse, syncope or incontinence). * Letter of referral from prospective study participant's referring physician, or similar primary provider - with copies of available medical evaluation and laboratory studies * Able and willing to consider a bone marrow biopsy and aspirate EXCLUSION CRITERIA: * Presence of conditions which in the judgment of the investigator or the referring…

What they're measuring

The primary objective of this study is to determine if patients with anaphylaxis (IA or SA) have clinical & laboratory features that correlate with genetic or molecular abnormalities in their mast cell population including the presence o...

Timeframe: 12/31/2028

Trial details

NCT IDNCT00719719

SponsorNational Institute of Allergy and Infectious Diseases (NIAID)

Sponsor typeNIH

Study typeOBSERVATIONAL