Growing up on a farm may protect against allergic rhinitis for life

Tweet

Studies have reported a low prevalence of allergic rhinitis in farmers and farmers' children.

In this Swedish study, a questionnaire on respiratory health was mailed to 30,000 randomly selected subjects aged 16–75. The response rate was 62%.

People that lived on a farm during their first 5 years of life had a lower prevalence of allergic rhinitis in all groups, even among the oldest (61–75 years).

The negative correlation between childhood farm living and allergic rhinitis was similar in 46–75 years of age (OR 0.82) as in 16–45 years of age (OR 0.78). There was a trend of increasing allergic rhinitis with increasing urbanization.

The study authors concluded that a lifelong protective effect of childhood farm living on the prevalence of allergic rhinitis.

References:

Eriksson J, Ekerljung L, Lötvall J, Pullerits T, Wennergren G, Rönmark E, Torén K, Lundbäck B. Growing up on a farm leads to lifelong protection against allergic rhinitis. Allergy 2010; DOI: 10.1111/j.1398-9995.2010.02397.x.

Protective role of contact with livestock and farming lifestyle on asthma, in particular during childhood. ERJ January 1, 2012 vol. 39 no. 1 67-75.

Image source: OpenClipArt.org, public domain.

Family history of allergies is the strongest determinant of eczema

Tweet

Eczema (atopic dermatitis) is a chronic inflammatory skin disease and is among the most frequent chronic conditions in childhood and adolescence.

This German study analyzed a nationwide survey including 17,000 children aged 0-17 (response rate: 67%).

The prevalence of physician-diagnosed eczema was 13%.

Positive associations were found for:

- parental allergies (OR 1.94)

- infection after birth (OR 1.45)

- jaundice after birth (OR 1.27)

Being a migrant (OR 0.63) and keeping a dog (OR 0.78) showed inverse associations with eczema.

This study suggests that a family history of allergies is the strongest determinant of eczema.

Atopic Dermatitis Treatment - Illustrated (click here for full size image).

References:
Determinants of eczema: population-based cross-sectional study in Germany. Apfelbacher CJ, Diepgen TL, Schmitt J. Allergy. 2010 Aug 30.

Image source: Wikipedia, public domain.

Sublingual immunotherapy (SLIT) review: effective, with no reported anaphylaxis or epinephrine use

Tweet

Allergic rhinitis is common worldwide, with significant morbidity and impact on quality of life. In patients who don’t respond adequately to anti-allergic drugs, subcutaneous allergen immunotherapy (SCIT) is effective but requires specialist administration.

Sublingual immunotherapy (SLIT) may represent an effective and safer alternative, according to the review authors. I would add that SLIT requires specialist prescription and monitoring as well (by an allergist/immunologist).

This Cochrane systematic review is an update of one published in 2003, and included 49 randomised, double-blind, placebo- controlled trials of sublingual immunotherapy in adults and children.

There were significant reductions in symptoms (standardised mean difference (SMD), −0.49; P less than 0.00001) and medication requirements (SMD −0.32) compared with placebo.

None of the trials reported severe systemic reactions, anaphylaxis or use of adrenaline (epinephrine). The authors concluded that sublingual immunotherapy (SLIT) is effective for allergic rhinitis and appears a safe route of administration.

References:
Radulovic S, Wilson D, Calderon M, Durham S. Systematic reviews of sublingual immunotherapy (SLIT). Allergy 2011; DOI: 10.1111/j.1398-9995.2011.02583.x.

Image source: Illustration for "Aquiline or Roman Nose", Wikipedia, GNU Free Documentation License.

People with a lot of nasal hair may be protected against asthma

Tweet

Larger particles entering the nose may be collected by nasal hair present in the anterior nares. Increased hair density could improve filtering efficiency of the nose.

Conversely, reduced amounts of nasal hair could decrease filter efficiency. Reduced filter function of the nose leads to increased exposure of the airways to allergens.

This Turkish study aimed to determine the effect of nasal hair density on the risk of developing asthma in 233 patients with seasonal rhinitis (SR).

Patients were divided into 3 groups according to the amount of nasal hair:

- few (few or none)
- moderate
- many

Asthma was detected in 32% of patients - and of these, 60% had "pollen asthma".

The rate of asthma was 45%, 26% and 17% in the few, moderate and many groups, respectively. Few nasal hairs significantly increased the risk of developing asthma.

The authors claim that the amount of nasal hair, providing a nose filtration function, has a protective effect on the risk of developing asthma in SR patients. To the best of their knowledge, this is the first report on this subject in the literature.


Rhinitis types, pathological classification (click to enlarge the image).



Treatment Options for Allergic Rhinitis (click to enlarge the image).

References:

Does Nasal Hair (Vibrissae) Density Affect the Risk of Developing Asthma in Patients with Seasonal Rhinitis? Ozturk AB, Damadoglu E, Karakaya G, Kalyoncu AF. Int Arch Allergy Immunol. 2011 Mar 30;156(1):75-80.

Image source: Wikipedia, a Creative Commons license.

Comments from Twitter:

@doc_rob Can you say "Rogaine nasal spray?" ( Minoxidil, a hair-regrowth medication is marketed under the brand name Rogaine).

@psufka: Uh, cool?... RT @DrVes: People with a lot of nasal hair may be protected against asthma.

@Laccheo: "People with a lot of nasal hair may be protected against asthma” And dates.

Direct oral provocation (no skin testing) in low risk patients with suspected penicillin allergy

Tweet

Suspected hypersensitivity to beta-lactam antibiotics (mostly pencillin derivatives) in children is a frequent cause of consultation. However, such hypersensitivity is rarely confirmed.

This Spanish study used a short protocol for patients at low risk. Low risk was defined as:

- single episode
- mild, non-immediate skin symptoms
- rash after the administration of a beta-lactam antibiotic via the oral route

The patients were subjected to oral provocation (after obtaining of informed consent) without any other prior evaluations (no skin testing).

Patients failing to meet these requirements were studied according to the protocol of the EAACI with:

- specific IgE
- skin testing
- tests done prior to oral provocation

The study with oral provocation was completed in 67 patients, and the short protocol was used in 50 of those patients.

Only one patient showed a positive provocation test, of a delayed and mild nature.

The authors concluded that direct oral provocation in low risk patients is effective and safe in discarding hypersensitivity to betalactam antibiotics.

References:
Short protocol for the study of paediatric patients with suspected beta-lactam antibiotic hypersensitivity and low risk criteria. Moral L, Garde J, Toral T, Fuentes MJ, Marco N. Allergol Immunopathol (Madr). 2011 Mar 21.

Image source: Penicillin nucleus, Wikipedia, GNU Free Documentation License.

Insect Sting Allergy - ACAAI Video

Tweet

Dr. Myron Zitt explains insect sting allergy and how allergy shots (immunotherapy) can help keep you protected. Information from the American College of Allergy, Asthma and Immunology.

Lactobacillus supplements may reduce risk of atopic dermatitis but not other atopic diseases

Tweet

Early reports suggested that Lactobacillus GG halved the risk of atopic dermatitis at 2 years.

This double-blind, randomized placebo-controlled trial of infants at risk of allergic disease included pregnant women in New Zealand.

Both mothers and their infants were randomized to take Lactobacillus rhamnosus HN001 (L. rhamnosus), Bifidobacterium animalis subsp lactis strain HN019 or placebo daily.

Mothers took the treatment from 35 weeks gestation until 6 months if breast-feeding. Infants received the same treatment from birth to 2 years.

Infants who received L. rhamnosus had a reduced risk of eczema. No such difference was noted with B. animalis subsp lactis.

Neither bacteria had a significant effect on other atopic diseases.

The authors concluded that oral supplementation with L. rhamnosus reduced the prevalence of eczema, but not atopy.


An example of commercially available OTC probiotic, Align at Costco Wholesale store.

References:

A differential effect of 2 probiotics in the prevention of eczema and atopy: A double-blind, randomized, placebo-controlled trial. Wickens K, Black PN, Stanley TV, Mitchell E, Fitzharris P, Tannock GW, Purdie G, Crane J; Probiotic Study Group. J Allergy Clin Immunol. 2008 Aug 31.

Image source: Bifidobacterium adolescentis. Wikipedia, GNU Free Documentation License.

Omalizumab reduced asthma exacerbations in patients older than 50 years by 69%

Tweet

Omalizumab is approved for the treatment of severe allergic asthma.

This study included 174 asthma patients 50 years or older (51% taking oral corticosteroids, and mean serum IgE level of 315 U/L) and 297 asthma patients younger than 50 years ( 50% taking oral corticosteroids, and mean serum IgE level of 363 U/L) who were treated with omalizumab for 4 months.

Omalizumab reduced the rate of severe exacerbations in patients 50 years or older by 69% and in patients younger than 50 years by 75%.

After 4 months there was a marked reduction of daily asthma symptoms and nocturnal awakenings by 68% and 73% in the older, and by 79% and 82% in the younger patients, respectively.

In 60% of patients 50 years or older lung function improved compared with 69% of patients younger than 50 years.

There was a higher rate of discontinuation of omalizumab therapy in older patients (21% vs 11%).

This study confirms the efficacy of omalizumab in patients with severe allergic asthma irrespective of age.



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

References:
Effectiveness of omalizumab in patients 50 years and older with severe persistent allergic asthma. Korn S, Schumann C, Kropf C, Stoiber K, Thielen A, Taube C, Buhl R. Ann Allergy Asthma Immunol. 2010 Oct;105(4):313-319.

Image source: Wikipedia, public domain.

Subsets of T regulatory cells

Tweet

Are all T reg cells Foxp3 positive?

No.

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

- 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 as of year 2010 (click to enlarge the image).

References:
T Cells. Jordan S. Orange MD/PhD. ACAAI/ACAAI Certification/Maintenance of Certification Board Review Course, 2008.

Regulatory T cells

Child asthma - inhaler techniques - NHSChoices video

Tweet

NHSChoices: The symptoms of childhood asthma, how it can be treated, and which inhaler is right for children.


Asthma Inhalers (click to enlarge the image).

Strongly suspected allergy to cashew but a negative skin test to cashew - what to do?

Tweet

A patient with urticaria and angioedema after eating cashews had a skin prick tests positive to almond and negative to cashew. How to explain it?

A negative food skin test is a good predictor of a negative food challenge, with greater than 95% certainty. However, one must have a "good quality" extract for skin test.

The incidence of "false-positive" skin tests to foods is much higher. The positive skin test to almond may not predict a clinical response, and may represent a sensitization without clinical reactivity.

Suggested approach:

- Specific IgE for cashew and almonds (sIgE)
- Prick-to-prick skin test using cashew nut (prick-puncture test)
- Get a fresh cashew extract and repeat the skin test
- See the container from which the cashew was taken to exclude cross-contamination with almonds, e.g. "made in a factory that also processes other tree nuts", etc.


8 top allergens account for 90 percent of food allergies. Specific IgE levels (sIgE) that predict the likelihood of passing an oral food challenge are shown in the figure. (click to enlarge the image).

References:
Acute urticaria after the ingestion of cashews with negative skin test to cashew. AAAAI Ask the Expert, 2011.

"Allergic to cashews, but thought it would be OK to eat almonds on AirFrance flight" - allergist on board saved his life http://goo.gl/P8Yh4

Latex Allergy - ACAAI Video

Tweet

Dr. David Bernstein explains latex allergy and how allergy testing can detect whether you are allergic to latex. Information from the American College of Allergy, Asthma and Immunology.


Latex allergy, a mind map diagram (click to enlarge).

Related:
Latex Allergy: Brief Review

How to Diagnose Latex Allergy

Latex Medical Gloves: Time for a Reappraisal. Int Arch Allergy Immunol 2011;156:234-246 (DOI: 10.1159/000323892).
Contact dermatitis to latex surgical gloves? There are limited choices for non-latex gloves: vinyl or nitrile. AAAAI, 2011. 

Eoxins could be a new therapeutic target for asthma

Tweet

Increased levels of leukotrienes (LTs) in exhaled breath condensate (EBC) are associated with asthma and bronchial hyperresponsiveness (BHR). Eicosanoids generated through the 15-lipoxygenase (LO) pathway (15-hydroxyeicosatetraenoic acid [HETE] and eoxins) have been less studied.

In a study of children with asthma eicosanoids were analyzed in EBC by using mass spectrometry.

Eoxins were increased in asthmatic children. The results point to increased activity of the 15-LO inflammatory pathway in childhood asthma. These markers might represent a new therapeutic target for asthma treatment.

Eicosanoid synthesis. Image source: Wikipedia.

Eicosanoids are signaling molecules made by oxygenation of 20-carbon essential fatty acids. There are 4 families of eicosanoids (PP-LT): prostaglandins (PG), prostacyclins (PGI), leukotrienes (LT) and thromboxanes (TX).

Arachidonic acid. Image source: Wikipedia.

LTC4 is a cysteinyl leukotriene, as are D4 and E4. Image source: Wikipedia.

LTB4. Note the four double bonds, three of them conjugated. This is a common property of A4, B4, C4, D4, and E4. Image source: Wikipedia.

Prostaglandin D2. Image source: Wikipedia.

References:
Eoxins: A new inflammatory pathway in childhood asthma. J Allergy Clin Immunol. 2010 Oct;126(4):859-867.e9.

Urticaria caused by antihistamines - a case report

Tweet

H1-antihistamines are the most frequently used drugs in allergic diseases.

This case report from Spain describes a patient with urticaria due to ingestion of ebastine and fexofenadine (Allegra). Skin prick tests, patch tests, and basophil activation tests with antihistamines were negative.

However, the oral challenges with the implicated antihistamines and other antihistamines tested were positive, with one exception. The patient tolerated an oral challenge with cetirizine.

The case report describes a patient with urticaria induced by different antihistamines in whom the diagnosis was established by oral challenge. However, the mechanism of sensitization remains unclear.



Oral Antihistamines, click here to enlarge the image.

References:
Urticaria due to antihistamines. Sánchez Morillas L, Rojas Pérez-Ezquerra P, Reaño Martos M, Sanz ML, Laguna Martínez JJ. J Investig Allergol Clin Immunol. 2011;21(1):66-8.

Comments from Twitter:

@rlbates: Could it be some of the pill/tablet additives?

10 people die of asthma in the U.S. every day - what can we do prevent it?

Tweet

Dr. Myron Zitt discusses the importance of early asthma detection and the Nationwide Asthma Screening Program (NASP). Information from the American College of Allergy, Asthma and Immunology.

Air pollution impairs T-regulatory cells and may worsen asthma

Tweet

Asthma is the most frequent chronic disease in children. Regulatory T (Treg) cells are suppressors of immune responses involved in asthma. Treg-cell impairment is associated with increased DNA methylation of Forkhead box transcription factor 3 (Foxp3), a key transcription factor in Treg-cell activity.

Children with and without asthma from California were enrolled in a cross-sectional study.

Treg-cell suppression was impaired and Treg-cell chemotaxis were reduced with ambient air pollution (AAP).

Foxp3 was decreased and contained higher levels of methylation with ambient air pollution (AAP).

Increased exposure to AAP is associated with hypermethylation of the Foxp3 locus, impairing Treg-cell function and increasing asthma morbidity. Ambient air pollution (AAP) could play a role in mediating epigenetic changes in Treg cells, which may worsen asthma.

Regulatory T cells - 5 groups have been described as of year 2010:

- CD4+CD25+ regulatory T cells ("classic" T regs)
- TR1 cells, CD4 cells that secrete IL-10

- Th3 cells, a subset of CD4+ cells that secrete TGF-b
- CD8+ suppressor T cells
- γ/δ T cells

Regulatory T cells - 6 groups have been described as of year 2010 (click to enlarge the image).


References:

Ambient air pollution impairs regulatory T-cell function in asthma. J Allergy Clin Immunol. 2010 Oct;126(4):845-852.e10.
Airways changes related to air pollution exposure in wheezing children: pollution decreases FEV1. ERJ, 2012.

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

"Sneeze Whisperer"

Tweet

The local Target store wants you to think their pharmacist is a "Sneeze Whisperer". The commercial is funny, but the reality is that you will get the best care, with the least amount of side effects, when you see your local board-certified allergist. Find an allergist, find relief.





Comments from Twitter:

@Stolib: Target pharmacist can whisper to sneezes, I'll focus on eliminating them

Asthma may increase the risk of erectile dysfunction

Tweet

The increased prevalence of erectile dysfunction (ED) has been reported in patients with chronic obstructive pulmonary disease (COPD), and systemic inflammation may play a role in this association. Asthma is also a chronic inflammatory airway disorder, eliciting a low-grade systemic inflammation.

This study analyzed a nationwide, population-based database in Taiwan from 2000 to 2007 which included newly diagnosed asthma cases in male patients 18–55 years old.

Of the 17,000 patients (asthmatics and controls), 0.66% experienced ED during the follow-up period of 4.5 years - 0.98% of the asthma patients and 0.58% from the control group.

Subjects with asthma experienced a 1.9-fold increase in incident ED, which was independent of age and other comorbidities. The risk of ED was higher with more frequent clinical visits for asthma.

Asthma may be an independent risk factor for ED, and risk of ED probably increases in accordance with asthma severity.

References:
Chou K-T, Huang C-C, Chen Y-M, Perng D-W, Chao H-S, Chan W-L, and Leu H-B. Asthma and risk of erectile dysfunction—A nationwide population-based study. J Sex Med, 2011.

Image source: Viagra (sildenafil), Wikipedia, GNU Free Documentation License.