Allergy Notes

Antibiotics could be useless in 95% of cases of acute sinusitis

2012-02-15T08:20:00.002-05:00

1 in 5 antibiotic prescriptions given to US adults is for treatment of sinusitis, but in most cases, the medication does not provide symptom relief. Almost 90% of patients who go to the physician’s office with sinusitis will walk out with a prescription for antibiotics.

This randomized, placebo-controlled trial included 166 adults with uncomplicated, acute rhinosinusitis from 10 community practices in Missouri over 3 years (JAMA, 2012).

10-day course of either amoxicillin (1500 mg/d) or placebo administered in 3 doses per day. Editor's note: the amoxicillin dose is low. Epocrates quotes amoxicillin dose of 1 g PO q8h x10 days, Max: 4 g/day; Alt: 1.5-4 g/day PO div q6-8h.

Here is the JAMA video which includes a brief interview with one of the authors:

The primary outcome was improvement in disease-specific quality of life after 3-4 days of treatment assessed with the Sinonasal Outcome Test-16 (Snot-16). Editor's note: All diagnoses were based on symptoms, no CT imaging was done. It is not even clear if the patients actuall had sinusitis or not.

Among patients with acute rhinosinusitis, a 10-day course of amoxicillin compared with placebo did not reduce symptoms at day 3 or day 10 of treatment.

In most cases, sinusitis develops after a cold, and this viral infection will be complicated by a bacterial infection - which can respond to antibiotic therapy - in less than 5% of cases. So, that means that antibiotics could be useless in 95% of cases of acute sinusitis.

However, considering the limitations of this study (low antibiotic dose, no imaging), I would await the results of a more rigorous trial before making significant changes to the current standard of care.

References:

Amoxicillin for Acute Rhinosinusitis. A Randomized Controlled Trial. JAMA. 2012;307(7):685-692. doi: 10.1001/jama.2012.138

Author Insights: Treatment of Acute Sinusitis With Antibiotics Often Futile. JAMA Blog.

Comments from Twitter:

CERTIFIED Allergy @allergysa: Disappointed more well-designed studies haven't been done. But even air-fluid levels won't necessarily point to BACTERIAL infection

Matthew Bowdish MD @MatthewBowdish: Lots of limitations RT @Allergy "Antibiotics No Help for Sinusitis" - however, read last few paragraphs for limitations http://goo.gl/WW7yC

Food Allergy and Dating - Anaphylaxis Canada Video

2012-02-14T08:06:00.000-05:00

Anaphylaxis Canada: Starting a new relationship can be very exciting, but if you or your partner has a food allergy, there are a few important things to remember to avoid having an allergic reaction. This video follows a couple who show the importance of open communication in having a safe and healthy relationship.

Related reading:

Food Allergy and Anaphylaxis Canada: "First Kiss" Video

Higher sensitivity in peanut allergy is associated with increasing age, sIgE, and eczema

2012-02-13T00:33:00.005-05:00

To date, it is not possible to predict the severity of allergic reactions to food in the individual patient. The allergists can predict the likelihood of an allergic reaction from the size of the skin prick test or the level of the sIgE, but not the severity of the reaction.

Data from children who had reactions to peanut during 126 double-blind, placebo-controlled food challenges (DBPCFCs) at the Swedish University Medical Center Groningen were analyzed (8 years).

Risk factors for reactions to lower doses included:

- age older than 10 years, hazard ratio 1.89

- specific IgE level above the lowest tertile (≥5.6 kU/L), hazard ratio 2

- absence of atopic dermatitis. Children without atopic dermatitis had more than twice the risk of reacting to a specific dose of peanut than did children with atopic dermatitis. Editor's note: this was an unexpected finding and the authors sounded surprised too in the discussion of the article. As usual, more studies are needed before a final conclusion can be made.

Greater clinical sensitivity in DBPCFCs to peanut was associated with increasing age, higher specific IgE level, and the absence of atopic dermatitis.

This finding may explain why adolescents experience severe allergic reactions in daily life to peanut more often than do younger children.

8 foods cause 90% of food allergies (TEMPS WFS) (click to enlarge the image). The likelihood of a negative oral food challenge is shown in relation to the respective values of skin prick test (SPT) and serum IgE (sIgE):

References:

The eliciting dose of peanut in double-blind, placebo-controlled food challenges decreases with increasing age and specific IgE level in children and young adults. Tjitske van der Zee et al. JACI, 2011.

Image source: Roasted peanuts as snack food, Wikipedia, public domain.

Food Allergy and Anaphylaxis Canada: "First Kiss" Video

2012-02-09T08:01:00.003-05:00

This Anaphylaxis Canada's "First Kiss" PSA is raising awareness for food allergies:

Person-to-person contact and food allergy

Saliva

Food allergen exposure through saliva may occur through:

- kissing
- sharing straws, glasses, or utensils

Kissing is the most common route of exposure: 5-12% of food allergy patients report reactions after kissing.

Source: The hazards of kissing when you are food allergic. A survey on the occurrence of kiss-induced allergic reactions among 1139 patients with self-reported food hypersensitivity. Eriksson NE; Moller C; Werner S; Magnusson J; Bengtsson U. J Investig Allergol Clin Immunol. 2003;13(3):149-54.

How long does food protein stay in saliva? "When is it safe to kiss after a meal?"

Time course of peanut protein (Ara h 1) in saliva after a meal of peanut butter:

- 87% had undetectable levels after 1 hour
- 100% had undetectable levels several hours later following a subsequent peanut-free lunch

Immediate brushing, prolonged rinsing, chewing gum did not produce a statisally significant difference.

Best option: wait several hours, then eat a peanut-free meal

Source: Peanut allergen exposure through saliva: assessment and interventions to reduce exposure. Maloney JM; Chapman MD; Sicherer SH. J Allergy Clin Immunol. 2006 Sep;118(3):719-24.

Other bodily fluids and food allergy

This is probably the first reported case of a sexually transmitted allergic reaction: A 20-year-old female with documented Brazil nut allergy developed urticaria and dyspnea after unprotected intercourse with her boyfriend who had earlier consumed Brazil nuts. Skin prick testing with the boyfriend's semen after Brazil nut consumption confirmed significant reactivity. A sample before nut consumption was negative.

Source: Dangerous Liaison: Sexually Transmitted Allergic Reaction to Brazil Nuts. J Investig Allergol Clin Immunol 2007; Vol. 17(3): 189-191.

References:

Food Allergen Avoidance

Comments from Twitter:

Elizabeth Goldenberg @Onespot_Allergy: When is it safe to kiss someone who's eaten peanuts? Answers via @Allergy

Anaphylaxis Canada @AnaphylaxisCAN: Thanks for tweeting about our "First Kiss" video and posting on your webpage accompanied by the valuable research on potential risks.

Vitamin D Deficiency is a Strong Predictor of Asthma in Children

2012-02-08T08:23:00.007-05:00

The aim of this study was to measure serum vitamin D levels in 500 asthmatic children in Qatar and to compare these to healthy non-asthmatic controls.

How did researchers define vitamin D deficiency?

Subjects with serum containing less than 20 ng/ml vitamin D were deemed deficient.

Asthmatic children had reduced serum vitamin D levels - 68% of all asthmatics were vitamin D deficient. Vitamin D deficiency was the strongest predictor of asthma in this population (OR 4.82).

Why were children deficient in vitamin D?

The majority of asthmatic children had less exposure to sunlight (67%) and less physical activity (71%).

This study revealed that the majority (68%) of asthmatic children had vitamin D deficiency. It remains to be seen if increasing the vitamin D level and correcting the deficiency improves the asthma control. Several studies are currently ongoing that evaluate the effects of vitamin D supplementation in children and adults with asthma. The results are expected in the next 1-2 years.

Severe asthma - differential diagnosis and management (click to enlarge the image). Workup for vitamin D deficiency should probably be included in the evaluation of severe asthma:

References:

Vitamin d deficiency as a strong predictor of asthma in children. Bener A, Ehlayel MS, Tulic MK, Hamid Q. Int Arch Allergy Immunol. 2012;157(2):168-75. Epub 2011 Oct 6.

Image source: Wikipedia, public domain.

New developments in the field of allergy

2012-02-07T08:16:00.013-05:00

This is a 2011 summary from the 200 articles published in the journal Clinical and Experimental Allergy in 2010. This is a little bit old but still interesting overview and my comments are added to each item below:

- Asthma and rhinitis phenotypes and biomarkers (phenotypes and endotypes) continue to be an important area of research.

- New therapies, including those derived from plants and herbs, are explored, e.g. Chinese herbal formula for treatment of food allergy is currently in trials at Mount Sinai.

- Pro-, pre- and synbiotics research remains a controversial and complicated field. The allergy-related research is not yet conclusive whether these substance are beneficial or not. Some studies have shown hints of efficacy in atopic dermatitis but the results are preliminary.

- Relationship between helminthic disease and allergy had a new twist in 2010-2011, involving studies using infection with helminths as a potential treatment.

- Genetics of allergic disease has moved on from only investigating single nucleotide polymorphisms (SNPs) of candidate genes to Genome Wide Association Studies (GWAS) and gene-environment interactions (epigenetics).

- There is a renewed interest in reactions to contrast media with some studies showing a higher rate of IgE-mediated reactions than previously anticipated, employing older and time-tested methods such as skin prick testing.

- There is a growing interest in the role of component resolved diagnosis, particularly in the field of food allergy, and peanut allergy, specifically. The first component resolved test for peanut allergy is now commercially available at the cost of $300. The test is not covered by health insurance.

Overall, these are exciting developments that hopefully will bring relief and lasting improvement to patients with allergic diseases. Feel free to add your comments in the section below this post.

References:

C. H. Katelaris, A. Linneberg, A. Magnan, W. R. Thomas, A. J. Wardlaw and P. Wark, Clinical & Experimental Allergy, 2011 (41) 1690-1710.

Image source: Wikipedia.

Food allergies challenge families - allergy doctors offer solutions

2012-02-06T08:30:00.001-05:00

Parents:

"We are living the impossible everyday," says a mom of two boys with multiple food allergies. "Food is everywhere. You have to be vigilant. It's a full-time job for me."

8 foods cause 90% of food allergies (TEMPS WFS) (click to enlarge the image). The likelihood of a negative oral food challenge is shown in relation to the respective values of skin prick test (SPT) and serum IgE (sIgE):

Allergists:

"There is a very high false positive rate. You can get a positive test, but the person can eat that food and nothing happens. A negative test is more accurate. If the test is negative, you almost certainly are not allergic to the food, whereas if it's positive, there is really only about 50% likelihood you are allergic."

Unless children show very high reactions on blood and skin tests, doctors can administer food challenges to find out if they are truly allergic. The blood and skin tests also can't predict whether children would have a mild or severe reaction to certain foods.

Oral Food Challenges (click to enlarge the diagram):

References:

Food allergies challenge families. USA Today.

Highlights of the last 10 years in immunology

2012-02-02T08:29:00.001-05:00

The journal Nature Reviews Immunology reached its 10th anniversary and the authors of one of the top-cited articles from each year took a trip down memory lane. See the results below.

The curved leucine-rich repeat region of toll-like receptors, represented here by TLR3. Image source: Wikipedia.

Some of the advances in immunology over the past 10 years include improved understanding of:

- Toll-like receptor signalling
- immune regulation mediated by regulatory T cells
- indoleamine 2,3-dioxygenase
- myeloid-derived suppressor cells
- interleukin-10
- heterogeneity of macrophages, dendritic cells and T helper cells

We all look forward to what the next 10 years of immunology research may bring.

References:

Highlights of 10 years of immunology in Nature Reviews Immunology. Nature Reviews Immunology 11, 693-702 (October 2011) | doi:10.1038/nri3063

What are the major risk factors for pediatric food anaphylaxis? Asthma and chronic GI symptoms

2012-02-01T08:29:00.000-05:00

This prospective study included 160 children with anaphylaxis seen at 29 outpatient allergy clinics throughout Italy. Food sensitization was evaluated by skin-prick test (SPT).

Mind map diagram of anaphylaxis (click to enlarge the image).

A clinical history of asthma increased the risk of wheezing during food-induced anaphylaxis (odds ratio (OR) 2.2) and respiratory arrest (OR 6.9).

A clinical history of chronic/relapsing gastrointestinal symptoms increased the risk of vomiting (OR 2.1), hypotension (OR 7.9), and bradycardia/cardiac arrest (OR 9.2).

Peanut and egg were the most frequent causes of severe anaphylaxis.

A history of asthma and chronic GI symptoms (probably linked to food allergy) may predict the development of respiratory and GI symptoms and the severity of anaphylaxis.

A generic version of the Anaphylaxis Action Plan is available from the AAAAI website.

References:

Risk factors for severe pediatric food anaphylaxis in Italy. Calvani M, Cardinale F, Martelli A, Muraro A, Pucci N, Savino F, Zappalà D, Panetta V; the Italian Society of Pediatric Allergy and Immunology (SIAIP) anaphylaxis’ study group. Pediatr Allergy Immunol. 2011 Sep 19. doi: 10.1111/j.1399-3038.2011.01200.x.
Anaphylaxis Action Plan

Patients with persistent airway obstruction due to refractory asthma have neutrophil-dominant airway inflammation

2012-01-31T08:57:00.013-05:00

Neutrophilic inflammation in refractory asthma may increase the likelihood of non-responsiveness to inhaled corticosteroids (ICS). This Korean study recruited 77 patients with refractory asthma from a cohort of 2,300 asthmatics.

The group with persistent airway obstruction had a longer duration of asthma and a higher frequency of near-fatal asthma despite the higher doses of inhaled corticosteroids. Neutrophilic inflammation was predominant in the group with persistent airway obstruction (PAO). Eosinophilic inflammation was predominant in the non-PAO group.

The study authors concluded that patients with persistent airway obstruction due to refractory asthma have neutrophil-dominant airway inflammation. This may provide the rationale for developing new asthma medications for individualized therapy.

References:

Role of neutrophils in persistent airway obstruction due to refractory asthma. Choi JS, Jang AS, Park JS, Park SW, Paik SH, Park JS, Uh ST, Kim YH, Park CS.Respirology. 2011 Nov 1. doi: 10.1111/j.1440-1843.2011.02097.x.

Image source: Wikipedia, free GNU license.

Montelukast failure index shows risk of failure before treatment is started

2012-01-30T08:16:00.004-05:00

Leukotriene receptor antagonist (LTRA) montelukast is an option for step-down therapy for mild asthmatics controlled on low-dose inhaled corticosteroids (ICS). Some patients fail montelukast step-down therapy, and it would be helpful to predict this risk. The Leukotriene or Corticosteroid or Corticosteroid-Salmeterol Study (LOCCS) trial included 165 participants.

Characteristics independently associated with montelukast treatment failure included:

- age of asthma onset <10 years old (OR = 2.39)
- need for steroid burst in the last year (OR = 2.39)
- pre-bronchodilator forced expiratory volume in 1 s (FEV1) (OR = 1.44 per 10% lower % predicted)

The montelukast failure index was based on these 3 variables (range: −5 to 7 points):

- scores <0 predicted low risk of treatment failure
- scores >5 predicted high risk of treatment failure

Summary

Early asthma onset, worse asthma control in the last year, and lower FEV1 are associated with montelukast treatment failure. A montelukast failure index is proposed to quantify the risk of failure prior to treatment initiation.

References:

Risk Factors for Montelukast Treatment Failure in Step-Down Therapy for Controlled Asthma. Drummond MB, Peters SP, Castro M, Holbrook JT, Irvin CG, Smith LJ, Wise RA, Sugar EA. J Asthma. 2011 Oct 27.

Image source: Montelukast, from Wikipedia, the free encyclopedia, public domain.

Winter skin care - Mayo Clinic video

2012-01-29T11:20:00.000-05:00

The falling temperatures of winter can be stressful for the largest organ of our body - our skin. Mayo Clinic experts offer some timely reminders for staying comfortable and healthy:

There are more videos here: Medical Edge 2012 by Mayo Clinic YouTube Channel

I recommend the following moisturizers:

Atopic Dermatitis Treatment - Illustrated (click to enlarge the image).

Amazon affiliate links:

30% of pet shop workers report airway symptoms at work and are sensitized to animal allergens

2012-01-26T09:07:00.000-05:00

Allergy to laboratory animals (mice, etc.) is a well-known occupational hazard. Less is known about allergic sensitization and respiratory symptoms among pet shop staff.

59 workers from 24 pet shops were included in this study from Sweden:

- 53% reported nasal symptoms
- 34% had eye symptoms
- 22% had experienced symptoms indicating asthma - only 7% were previously diagnosed with asthma
- 30% reported respiratory symptoms at work, mostly against rodents, birds, insects, and hay
- 29% were sensitized to work-related allergens, mainly rodents and fodder insects, e.g., Zophobas

Atopy and total IgE higher than 100 kU/l increased prevalence of pet shop sensitization.

A third of the pet shop workers reported airway symptoms at work or were sensitized, sometimes to unusual pet shop allergens, especially among atopics. Allergen avoidance among pet shop staff is important but may be difficult to achieve.

Mind map: Indoor allergens (click to enlarge the image).

Mind map: Animal Dander Avoidance (click to enlarge the image).

References:

Renström A, Olsson M, Hedrén M, Johansson SGO, van Hage M. Pet shop workers: exposure, sensitization, and work-related symptoms. Allergy 2011; DOI: 10.1111/j.1398-9995.2011.02591.x.

Image source: Wikipedia, GNU Free Documentation License.

Status of pediatric allergy and immunology in Spain

2012-01-26T08:04:00.002-05:00

The data of the ISAAC project in Spain show:

- prevalence of childhood asthma of 7-15%
- prevalence of 23-36% for rhinitis
- atopic dermatitis in 4-8% of children
- prevalence of food allergy is 3%

All children in Spain have the right to be evaluated in their National Health System. The medical care at the primary level is provided by pediatricians, who go through a 4-year medical residency training program.

There are currently 112 certified pediatric allergists in Spain, who have obtained the accreditation of the European Union of Medical Specialists. Future specialists in pediatric allergy will obtain their titles through a specific education program to be developed in one of the 4 accredited training units on pediatric allergy, after pediatric residency.

The Spanish Society of Pediatric Allergy and Clinical Immunology (SEICAP) includes 350 pediatric allergists and pediatrician. SEICAP has yearly congresses and protocols. The official journal of SEICAP is Allergologia et Immunophatologia, published every 2months since 1972.

The web site of SEICAP, http://www.seicap.es, open since 2004, received 750 daily visits during 2011.

The pediatric allergy units perform immunotherapy and induction of oral "tolerance" in food allergy.

References:

Nieto A, Mazon A, Martin-Mateos MA, Plaza A-M, Garde J, Alonso E, Martorell A, Boquete M, Lorente F, Ibero M, Bone J, Pamies R, Garcia JM, Echeverria L, Nevot S, Martinez-Cañavate A, Fernandez-Benitez M, Garcia-Marcos L. Pediatric allergy and immunology in Spain. Pediatric Allergy Immunology 2011; 22: 742-750.

Image source: Openclipart.org, public domain.

Comments from Twitter:

Dr John Weiner @AllergyNet: Like in tennis, the Spanish punch above their weight in allergy/immunology

PPI lansoprazole doesn't help children with poorly controlled asthma if they don't have reflux symptoms (GERD)

2012-01-25T08:24:00.055-05:00

Asymptomatic gastroesophageal reflux (GER) is prevalent in children with asthma. Untreated GER has been postulated to be a cause of inadequate asthma control. However, it it not clear if treating asymptomatic GERD with proton pump inhibitors (PPI) helps the asthma symptoms.

300 children with asthma with mean age of 11 years were enrolled at 19 US academic clinical centers and were followed up for 6 months.

There were no significant differences in:

- the Asthma Control Questionnaire (ACQ) score (primary outcome),
- FEV1, forced expiratory volume in the first second
- asthma-related quality of life
- asthma exacerbations

Watch the JAMA video report on the study:

Among the 115 children with esophageal pH studies, the prevalence of GER was 43%. In the subgroup with a positive pH study, lansoprazole did not affect asthma outcomes.

There were slightly more respiratory infections in the PPI group (relative risk, 1.3).

In this trial of children with poorly controlled asthma without symptoms of GER who were using inhaled corticosteroids, the addition of lansoprazole, did not improve symptoms or lung function.

The key here may be whether the children with asthma have symptoms of GERD or not. A 2008 study, presented at the annual ACAAI meeting, showed that "in children with both asthma and gastroesophageal reflux disease (GERD), treating the latter can improve the former."

Severe asthma - differential diagnosis and management (click to enlarge the image). Related: Common Asthma-related Comorbidities. Medscape, 2011, (figure) http://j.mp/omHVc6

References:

Lansoprazole for Children With Poorly Controlled Asthma. JAMA. 2012;307(4):373-380. doi: 10.1001/jama.2011.2035

Costs and Perils of Therapeutic Creep: Children, Asthma, and Proton Pump Inhibitors - JAMA editorial.

"Childhood Asthma - JAMA Patient Page" mistakenly skips allergy tests in asthma evaluation but includes CXR (PDF). All children with asthma should undergo allergy testing in order to identify potential allergic triggers (http://goo.gl/tosfJ).

T reg cells may offer a key for treatment of autoimmune diseases

2012-01-24T08:15:00.001-05:00

T regulatory cells (Treg) are distinguished by CD4+, CD25+, GITR+, CTLA-4+. Some of T regs also express the transcription factor Foxp3 (nTreg).

Treg subsets include:

- Natural Tregs (nTreg). nTregs develop in the thymus and constitutively express Foxp3 and CD25. They depend upon IL-2 for their survival.

- Induced Tregs (iTreg). iTregs are induced from naïve CD4 in the periphery. They express Foxp3 only after development by TGF-b.

- T Regulatory 1 (Tr1). Tr1 do not express CD25 or Foxp3. They depend on IL-10 from DCs for development. Tr1 produce high levels of IL-10.

Regulatory T cells - 6 groups have been described (click to enlarge the image).

A lack of regulatory T (TReg) cells that express CD4, CD25 and forkhead box P3 (FOXP3) results in severe autoimmunity in humans (IPEX).

There has been intense investigation aimed at determining how they protect an organism from autoimmunity and whether defects in their number or function contribute to the development of autoimmunity.

The next phase of investigation — focused on defining the role that defects in TReg cells have in human autoimmunity — is now underway. This knowledge might have a significant impact on the diagnosis and treatment of autoimmune diseases.

References:

Mechanisms of impaired regulation by CD4+CD25+FOXP3+ regulatory T cells in human autoimmune diseases. Nature Reviews Immunology 10, 849-859 (December 2010) | doi:10.1038/nri2889

Regulatory T cells

Image source: A scanning electron microscope (SEM) image of a single human lymphocyte.Wikipedia, public domain.

Needles/lancets are tools of choice for skin prick testing - according to a study comparing 5 techniques in Europe

2012-01-23T08:28:00.020-05:00

Skin prick tests (SPT) represent indispensable tools in allergy, even more than 30 years after their introduction in clinical practice (note: skin prick testing has been used in the U.S. for a lot longer than 30 years).

A wheal with multiple pseudopods and a satellite lesion in the upper left. Image source: Modified from Sakurako Kitsa's photostream, Flickr (used with the author's permission).

Four instruments were investigated in this European study:

- 23G intravenous (IV) needle
- ALK Lancet - SoluPrick SQ (TM)
- Stallergenes (STG) Prick Lancet
- Stallerpoint (using two different methods)

In terms of sensitivity, the IV needle (100%) and metal lancets (96% for the ALK Lancet and 98% for the STG Prick Lancet) were superior to the two Stallerpoint® methods (20% and 57%).

The instruments that were best tolerated by the patients were the IV needle and the two metal lancets.

The authors concluded that metal needles and/or lancets are the tools of choice for skin prick testing. The study did not include some of the most popular devices for SPT in the U.S. such as:

- ComforTen (PDF)
- Multi-Test II (instructions)

Quintest device

Comparison of diagnostic methods for peanut, egg, and milk allergy - skin prick test (SPT) vs. specific IgE (sIgE) (click to see the spreadsheet). Sensitivity of blood allergy testing is 25-30% lower than that of skin testing, based on comparative studies (CCJM 2011).

Skin prick test vs. serum IgE

Skin testing correlates better with nasal allergen challenge (the gold standard) than blood testing for the diagnosis of inhalant allergy. According to current guidelines, skin tests are the preferred method for diagnosing IgE-mediated sensitivity to inhalants (CCJM 2011).

References:

Comparison of five techniques of skin prick tests used routinely in Europe. Masse MS, Granger Vallée A, Chiriac A, Dhivert-Donnadieu H, Bousquet-Rouanet L, Bousquet P-J, Demoly P. Comparison of five techniques of skin prick tests used routinely in Europe. Allergy 2011; DOI: 10.1111/j.1398-9995.2011.02679.x.

Comparison of the Multi-Test II and ComforTen allergy skin test devices. Dykewicz MS, Dooms KT, Chassaing DL. Allergy Asthma Proc. 2011 May;32(3):198-202.

Skin prick tests (SPT)

Bullying, teasing, and harassment of children with food allergy is common, frequent, and repetitive

2012-01-18T08:43:00.018-05:00

This U.S.based study from Mount Sinai Hospital in New York City included 350 questionnaires. Most surveys were completed by parents of food-allergic children.

24% of respondents reported that the food-allergic individual had been bullied, teased, or harassed because of food allergy.

Of those who were bullied, teased, or harassed, 86% reported multiple episodes. 82% of episodes occurred at school, and 80% were perpetrated by classmates.

21% of those who were bullied, teased, or harassed reported the perpetrators to be teachers or school staff.

Of those bullied, 57% described physical events, such as being touched by an allergen and having an allergen thrown or waved at them, and several reported intentional contamination of their food with allergen.

Bullying, teasing, and harassment of children with food allergy seems to be common, frequent, and repetitive. These actions pose emotional and physical risks that should be addressed in food allergy management.

References:

Bullying among pediatric patients with food allergy. Lieberman JA, Weiss C, Furlong TJ, Sicherer M, Sicherer SH. Ann Allergy Asthma Immunol. 2010 Oct;105(4):282-286.

Food allergy bullies - ABC video

Image source: Wikipedia, public domain.

Lung function decreases and AHR increases with greater sgE levels or SPT wheal diameter to inhalant allergens

2012-01-17T08:06:00.008-05:00

Studies in children show specific serum IgE (sIgE) and size of skin test wheal to inhalant allergens predict wheezing and reduced lung function. Few studies in adults have investigated that link.

FEV1 and FVC (% predicted) were measured using spirometry and airway responsiveness by methacholine challenge (5-breath dosimeter protocol) in 1,000 UK adults (controls and 183 patients with asthma).

Atopic status was assessed by skin prick tests (SPT) and sIgE to common inhalant allergens. Sensitization was defined using standard definitions for sIgE>0.35kUa/l and SPT 3mm>negative control.

16% of subjects showed evidence of airway hyperresponsiveness (AHR).

Increasing levels of sIgE to dust mite, cat and dog were associated with lower FEV1.

Similar findings were observed when using the size of wheal on skin testing, with decreasing lung function with increasing skin test size (dust mite, cat, dog, grass).

Lung function decreased and AHR increased with increasing sgE levels or SPT wheal diameter to inhalant allergens. Atopy influences lung function and AHR.

References:

Quantification of atopy, lung function and airway hypersensitivity in adults. Susana Marinho, Angela Simpson, Paul Marsden, Jacky A Smith and Adnan Custovic. Clinical and Translational Allergy 2011, 1:16.

Image source: Spirometry, from Wikipedia, the free encyclopedia, GNU Free Documentation License.

Related:

IL-10-producing B cells (regulatory B-cells) induction by helminths may open a new avenue in asthma treatment

2012-01-16T08:58:00.008-05:00

Chronic helminth infections are often associated with a reduced prevalence of inflammatory disorders, including allergic diseases.

Helminths influence the immune system by downregulating T-cell responses and IL-10 appears to play a central role in this process.

Over the last decade, evidence has emerged for a new regulatory cell type, in addition to the well-known T regs: IL-10-producing B cells (regulatory B cells).

Initially, regulatory B cells were described in autoimmunity models where they decrease inflammation. Patients suffering from autoimmunity have an impaired regulatory B-cell function. They were also found in several helminth infection models.

Helminth-induced regulatory B cells suppress allergic inflammation and may open a new avenue for the treatment of inflammatory diseases, such as allergic asthma.

Regulatory T cells - 6 groups have been described (click to enlarge the image).

References:

Regulatory B-cell induction by helminths: Implications for allergic disease. Hussaarts L, van der Vlugt LE, Yazdanbakhsh M, Smits HH. J Allergy Clin Immunol. 2011 Jun 17.

Interleukin-10 (IL-10)

Image source: Trichuris egg in stool sample (40x). Wikipedia, GNU Free Documentation License, Version 1.2.

What are the risk factors and protective factors for allergic rhinitis at age 4?

2012-01-13T08:39:00.000-05:00

Allergic heredity plays a significant role in the development of allergic rhinitis. The introduction of solid foods may also influence the risk of allergic disease.

Allergic (atopic) march (click here to enlarge the image).

This Swedish study analysed early risk factors and protective factors for allergic rhinitis at preschool age (4 years) via questionnaires.

At 4½ yr of age, 5.5% of children had reported symptoms of allergic rhinitis.

Risk factors for allergic rhinitis were:

- allergic sensitisation to food allergens at 4½ yr (OR 10.21)
- recurrent wheeze at 4½ yr (3.33)
- doctor-diagnosed eczema at 4½ yr (2.72)
- parental rhinitis (2.21)
- eczema first year (1.97)
- male gender (1.82)

The risk was reduced with fish introduction before 9 months of age (0.49).

References:

Alm B, Goksör E, Thengilsdottir H, Pettersson R, Möllborg P, Norvenius G, Erdes L, Åberg N, Wennergren G. Early protective and risk factors for allergic rhinitis at age 4½ yr. Pediatr Allergy Immunol 2011: Doi: 10.1111/j.1399-3038.2011.01153.x

Allergen-specific immunotherapy was performed by the ancient king Mithridates (132-63 B.C.)

2012-01-12T08:57:00.004-05:00

A hundred years ago, Leonhard Noon and John Freeman published their pioneering works on allergen-specific immunotherapy (ASIT) using grass pollen extracts.

ASIT is the only causal treatment of IgE-mediated allergies. The history of ASIT started with the anecdotal descriptions of ASIT performed by the ancient king Mithridates (132–63 B.C.) and Jenner’s development of a cowpox vaccine.

Some of the products used for ASIT include:

- aqueous pollen extracts
- whole bee extracts
- chemically modified allergens (allergoids)
- various recombinant allergens

In addition to allergen-specific immunotherapy, non-specific immune response modifiers have been used in the past, or are in the developmental stage.

Mechanisms of allergen-specific immunotherapy (click to enlarge the image).

References:

Ring J, Gutermuth J. 100 years of hyposensitization: history of allergen-specific immunotherapy (ASIT). Allergy 2011; DOI: 10.1111/j.1398-9995.2010.02541.x.

Allergen immunotherapy was introduced by Leonard Noon 100 years ago and is the only disease-modifying treatment for allergic individuals (Allergy, 2012).

Image source: OpenClipArt.org, public domain.

Girl's death highlights allergy safety in schools - CNN video

2012-01-11T19:03:00.001-05:00

Key points:

- There is no cure for food allergies

- About 8% of U.S. children under 18 have at least one food allergy

- Epinephrine is the first line life-saving medication in severe food allergic reaction. Always carry an EpiPen with you, and remember these simple memory rules in severe food allergic reaction:

- "No Epi, no eat-y" (always carry an EpiPen with you, don't sit down to eat if you don't have an EpiPen available)

- "If it's more than the skin, the Epi goes in" (only mild hives may respond to antihistamine, for anything else you may need an EpiPen)

References:

Girl's death highlights allergy safety in schools. CNN, 2012.

Are Profilins Mimickers of Allergy or Mighty Pan-Allergens?

2012-01-11T09:10:00.003-05:00

Profilins are ubiquitous proteins, present in all eukaryotic cells and identified as allergens in pollen, latex and plant foods.

Profilins have a highly conserved structure that may be the reason for cross-reactivity. IgE antibodies against plant profilins react to wide varity of allergens, hence the designation of prolifins as pan-allergens.

Primary sensitization to profilin arises from pollen sensitization with later development of cross-reactive IgE antibodies against plant food (and possibly latex) profilins.

Cross-reactivity in Pollen-Food Allergy Syndrome (PFAS) or Oral Allergy Syndrome (OAS) (click to enlarge the image).

IgE cross-reactivity among profilins is associated with multiple pollen sensitization and with various pollen-food syndromes (oral allergy syndrome).

In respiratory allergy, sensitization to pollen to which the patient has virtually no environmental exposure has been identified as a manifestation of profilin sensitization.

As a food allergen, profilin usually elicits mild reactions, such as oral allergy syndrome. However, 1-10% of patients with oral allergy syndrome may develop anaphylactic reactions, and many allergists started prescribing EpiPens to the patients with this condition.

Prolifins are especially important in allergy to some fruits, such as melon, watermelon, banana, tomato, citrus fruit and persimmon.

Natural and recombinant profilins are available for in vitro and in vivo allergy tests in some countries.

Although the role of profilins in triggering allergic symptoms is still controversial, they are relevant allergens. As a pan-allergen, profilin is associated with multiple pollen sensitization and pollen-food-latex syndromes that allergists, and other physicians, must to be aware of.

References:

Profilins: Mimickers of Allergy or Relevant Allergens? Santos A, Van Ree R. Int Arch Allergy Immunol. 2011 Feb 2;155(3):191-204.

Single dose of dexamethasone as effective as a 5-day course of oral steroids for asthma exacerbations in children

2012-01-10T08:57:00.016-05:00

Traditionally, mild-to-moderate pediatric asthma exacerbations have been treated with a short course of oral steroids - often 5 days of prednisone or prednisolone. According to a recent review from the journal Canadian Family Physician, a similar outcome can be acheived with a single dose of dexamethasone, which has a longer half-life and powerful anti-inflammatory effects, along with easier administration and compliance.

Oral administration of dexamethasone is the preferred route, especially considering the 80% bioavailability.

One study followed 110 children at 5 days after randomization to either a single dose of oral dexamethasone (0.6 mg/kg, maximum 18 mg) or oral prednisolone (1 mg/kg per dose, maximum 30 mg) twice daily for 5 days. Overall hospital admission rates at 5 days did not differ significantly between dexamethasone and prednisolone. Self-assessment scores returned to baseline in 5 days in both groups.

References:

Single-dose dexamethasone for mild-to-moderate asthma exacerbations: Effective, easy, and acceptable. Cross KP, Paul RI, Goldman RD. Can Fam Physician. 2011 Oct;57(10):1134-6.

Image source: Dexamethasone, Wikipedia.