Allergy & Immunology
Expert discussions on allergic conditions, immunodeficiencies, drug hypersensitivity, and immunotherapy approaches.
Recent Discussions
Can you have an allergic reaction to paprika if you have tree nut allergy?
Yes - according to a paper published, there is significant cross-reactivity between chili peppers and Brazil nut and hazelnut at least in laboratory assays, however clinical reactivity was not correlated in this paper (Ivens et al., PMID 34714660):"The xMAP food allergen detection assay (xMAP FADA) ...
Do you continue to check tryptase levels in your patients with idiopathic anaphylaxis despite normal levels >5 on repeated checks?
Baseline serum tryptase levels have been reported to be quite stable in the vast majority of patients, but can vary more in people with HaT or mastocytosis. With a bST <8 ng/ml, there is no obvious reason to continue to check it. However, even with normal bST, the Practice Parameters recommend furth...
What VIT would you recommend in a patient who had grade 5 anaphylaxis to a stinging insect but negative IDT and serum IgE?
The short answer is none. Venom immunotherapy (VIT) is absolutely dependent on demonstrating specific IgE to the suspected agent. Without specific IgE, I would not recommend starting VIT. When faced with the dilemma of post-insect sting anaphylaxis and negative skin tests(ST) and serum tests, the fi...
How do you handle hypogammaglobulinemia detected in patients prior to maintenance rituximab infusion?
That is a good question. Adding on to Dr. @Dr. First Last's response, rituximab has been shown to cause hypogammaglobulinemia that can persist or worsen with ongoing therapy. In a study published by Barmettler and colleagues, 133 patients out of a cohort of 8633 patients had serum IgG levels checked...
Are you requiring markers other than LTE4 to be elevated to diagnose MCAS?
The commercially available biomarkers to assess systemic mast cell activation in vivo include serum tryptase, N-methyl histamine (major metabolite of histamine), various forms of 11-beta-PGF2-alpha (PGD2 metabolite), and LTE4 (major metabolite of LTC4). The metabolites of these small molecules are m...
Do all patients initiating omalizumab need to have it administered in a healthcare setting?
In the trials, all cases of anaphylaxis were on first administration--suggesting it is not intrinsic to drug and is more likely because you are giving it to a group of people who may be more susceptible to anaphylaxis in general. FDA has cleared at home use, so my general approach in a patient witho...
Would you consider anti-IL-5 therapy (mepolizumab or benralizumab) to either prevent or treat the more severe manifestations of eosinophilic granulomatosis with polyangiitis, such as "infiltrative" (e.g., cardiomyopathy, pulmonary infiltrates, or gastroenteritis) or "vasculitic" (e.g., neuropathy, palpable purpura, or glomerulonephritis)?
Yes, I would consider early starting biologics for infiltrative EGPA.
Should a patient who has hereditary alpha tryptasemia and has experienced multiple anaphylactoid reactions be tested for a venom allergy and started on VIT if positive?
No. Only individuals with a history of anaphylaxis following a Hymenoptera insect sting should be offered venom-specific IgE testing and/or skin testing. There are rare exceptions, including beekeepers with frequent large local reactions. The person from the question stem does not have a history of ...
What is your approach to distinguishing a Jarisch-Herxheimer reaction from a delayed anaphylactoid reaction?
As with most things in medicine, this is context-dependent. The Jarisch-Herxheimer reaction is a systemic inflammatory response to the death of bacteria (most commonly associated with spirochetes and in particular, syphilis), typically in the hours following antibiotic administration. This response ...
What medications would you have a patient avoid with an IgE mediated reaction to cyclobenzaprine?
The mechanism of immediate hypersensitivity to cyclobenzaprine is likely MRGPRX2-mediated rather than IgE-mediated. MRGPRX2 is a G-protein coupled receptor (GPCR) predominantly expressed in human mast cells. Upon activation, MRGPRX2 triggers mast cell degranulation and anaphylactic reactions. MRGPRX...