Author: V. Dimov, M.D., Allergist/Immunologist and Assistant Professor at University of Chicago
Reviewer: S. Randhawa, M.D., Allergist/Immunologist and Assistant Professor at NSU
A 35-year-old female is seen in the allergy clinic for evaluation of suspected food allergy. Three months ago, she had abdominal discomfort and shortness of breath within minutes of eating chocolate-covered almonds. She had a methacholine challenge test which was negative. She is here to determine if food or environmental allergies played a role in her symptoms.
Past Medical History: negative.
Medications: none. NKDA.
Physical Examination: HEENT: "allergic shiners". Otherwise unremarkable.
What is the most likely diagnosis?
Food allergy is on the list of differential diagnoses.
What type of diagnostic tests would you suggest?
She had percutaneous skin testing with indoor, outdoor, and food allergens.
Airborne allergens: Positive for Cockroach. Negative for Dust mite, Cat, Dog, Mold, Trees, Grass, Weeds, Ragweed.
Food allergens: negative for Tree nuts (almond, walnut, sesame, hazelnut, pistachio, Brazil nut). Egg, Milk, Peanut, Soy, Wheat, Fish, Shellfish.
Female Blatella germanica cockroach with ootheca (eggs). Image source: Wikipedia, public domain.
What is the cause of this patient’s symptoms?
Allergic rhinitis with sensitization to cockroach. Suspected food allergy with symptoms related to cross-contamination with cockroach.
Patients who consume food products contaminated with cockroach parts such as chocolate or nuts may have an allergic reaction. Her reaction to chocolate-covered almonds could be related to cross-contamination with cockroach. On average, 8 insect parts are found per chocolate bar and deemed safe for most people, according to the FDA’s guidelines.
Skin testing has a 30% greater sensitivity than serum IgE (Cleveland Clinic J of Med, 2011, 78-9, 585-592), and a negative skin test typically rules out clinical environmental or food allergy in approximately 90% of patients.
What would you suggest to prevent future reactions?
Regarding her allergic rhinitis, we recommended avoidance of relevant allergens cetirizine 10 mg po qpm to be used as needed.
Regarding the suspected food allergy, we recommended complete avoidance of tree nuts and peanut due to cross-contamination risk and pending workup for food allergy. EpiPen was prescribed, and she was educated on its use. In case of anaphylaxis, she should call 911. We also provided a food allergy action plan and links to the educational videos on our teaching web site.
An oral food challenge with almond was suggested to rule out food allergy to almond conclusively.
Related reading
Chocolate Allergy? It's Vanishingly Rare
"Chocolate Allergy" is actually due to cockroach in chocolate - up to 60 insect parts per 100 gm bar "acceptable". ABC News, 2012.
FDA Info sheet
Published: 11/28/2011
Updated: 04/08/2012
Showing posts with label Cases. Show all posts
Showing posts with label Cases. Show all posts
Almond allergy? No, it’s allergy to cockroach-contaminated chocolate-covered almonds
How to rule out suspected allergy to Diphtheria Toxoid and Acellular Pertussis (Tdap) vaccine?
Author: V. Dimov, M.D., Allergist/Immunologist and Assistant Professor at University of Chicago
Reviewer: S. Randhawa, M.D., Allergist/Immunologist and Assistant Professor at NSU
A 3-year-old girl is seen in the allergy clinic with a referral for a suspected allergy to the Diphtheria Toxoid and Acellular Pertussis (Tdap) vaccine. At age 2 months, after the first administration of Tdap vaccine, she became irritable approximately 2 hours after that, and she was screaming for more than 4 hours. The same behavior was repeated for 3-4 days. It was a traumatic experience for both the parents and the baby who required an ER visit. Since then, she was only administered the Td component, without the acellular pertussis component. She is otherwise a healthy girl, without symptoms of allergic disease.
Past Medical History: negative.
Medications: None. NKDA.
Physical Examination is unremarkable.
What is the most likely cause of her symptoms?
The described episode with screaming for more than 4 hours may occur in approximately 1 in 1000 of the immunizations for pertussis. An allergic reaction occurs in approximately 1 in a million doses. Her symptoms at age 2 months were not suggestive of an allergic reaction.
How to rule out allergic reaction to Tdap in this patient?
A graded dose challenge with Tdap vaccine was performed. The challenge followed the established protocol with monitoring of the vital signs and serial physical examinations every 15 minutes. She received 10% of the Tdap vaccine. After 30-minute observation, the remaining 90% of the vaccine was administered. She was observed in the clinic for another 30 minutes after the second dose. There were no signs of adverse effects to the vaccine.
Final diagnosis
History of adverse reaction to Tdap vaccine. Negative graded dose challenge with Tdap vaccine.
What would you suggest during the future administrations of the Tdap vaccine?
The graded dose challenge with Tdap vaccine was negative today and future doses can be administered in the pediatrician’s office with a 30-minute observation period after the administration of the vaccine.
What is the risk for encephalopathy with Tdap vaccine?
Acute encephalopathy occurs extremely rarely with whole-cell pertussis (DTP) vaccines (ratio of 0-10.5 cases to one million doses administered). Neither anaphylaxis nor encephalopathy occurred during clinical trials that involved administration of 26,000 doses of ACEL-IMUNE vaccine. Source: CDC.
Overdiagnosis of vaccine allergy is a major public health problem http://buff.ly/1tI9y44
Vaccine Adverse Reactions - Algorithms:
References
Management of an adult with a possible allergic reaction to DPT vaccine - advice from AAAAI Ask the Expert, 2012.
Published: 11/28/2011
Updated: 05/08/2012
Reviewer: S. Randhawa, M.D., Allergist/Immunologist and Assistant Professor at NSU
A 3-year-old girl is seen in the allergy clinic with a referral for a suspected allergy to the Diphtheria Toxoid and Acellular Pertussis (Tdap) vaccine. At age 2 months, after the first administration of Tdap vaccine, she became irritable approximately 2 hours after that, and she was screaming for more than 4 hours. The same behavior was repeated for 3-4 days. It was a traumatic experience for both the parents and the baby who required an ER visit. Since then, she was only administered the Td component, without the acellular pertussis component. She is otherwise a healthy girl, without symptoms of allergic disease.
Past Medical History: negative.
Medications: None. NKDA.
Physical Examination is unremarkable.
What is the most likely cause of her symptoms?
The described episode with screaming for more than 4 hours may occur in approximately 1 in 1000 of the immunizations for pertussis. An allergic reaction occurs in approximately 1 in a million doses. Her symptoms at age 2 months were not suggestive of an allergic reaction.
How to rule out allergic reaction to Tdap in this patient?
A graded dose challenge with Tdap vaccine was performed. The challenge followed the established protocol with monitoring of the vital signs and serial physical examinations every 15 minutes. She received 10% of the Tdap vaccine. After 30-minute observation, the remaining 90% of the vaccine was administered. She was observed in the clinic for another 30 minutes after the second dose. There were no signs of adverse effects to the vaccine.
Final diagnosis
History of adverse reaction to Tdap vaccine. Negative graded dose challenge with Tdap vaccine.
What would you suggest during the future administrations of the Tdap vaccine?
The graded dose challenge with Tdap vaccine was negative today and future doses can be administered in the pediatrician’s office with a 30-minute observation period after the administration of the vaccine.
What is the risk for encephalopathy with Tdap vaccine?
Acute encephalopathy occurs extremely rarely with whole-cell pertussis (DTP) vaccines (ratio of 0-10.5 cases to one million doses administered). Neither anaphylaxis nor encephalopathy occurred during clinical trials that involved administration of 26,000 doses of ACEL-IMUNE vaccine. Source: CDC.
Overdiagnosis of vaccine allergy is a major public health problem http://buff.ly/1tI9y44
Vaccine Adverse Reactions - Algorithms:
References
Management of an adult with a possible allergic reaction to DPT vaccine - advice from AAAAI Ask the Expert, 2012.
Published: 11/28/2011
Updated: 05/08/2012
Subscribe to:
Posts (Atom)