Turbinates to Bronchioles: the one airway concept in asthma treatment - Twitter summary from 2014 #ACAAI


Allergies and asthma

Dr. Tim Craig discussed adult asthma: Defining allergies in asthma can allow to develop plans for avoidance, determine if immunotherapy, or monoclonals are indicated.

@DrAnneEllis: In one of Craig's studies, 95% of asthmatics had positive skin tests. Much higher than what I see in my practice.

The rates of positive skin tests are higher in those whose asthma onset was before the age of 30. In a cohort of NON-allergic asthmatics, there were more females and cough was the prominent symptom. Those asthmatics with cat allergy had lowest PC20 values on methacholine challenge, ie more severe disease. The article by Wu et al JACI 2014 133: 1280-8 defines 6 endotypes of asthma, based on allergic status, obesity, presence of polyps, and others. Dr Craig showed the meta-analysis by @AllergyNet demonstrating clear benefit of immunotherapy in the treatment of asthma. A @CochraneAirways meta-analysis of SLIT showed benefits for AR symptoms and medication use, but for asthma p value didn't quite make it.

Non-allergic rhinitis (NAR)

Dr. Jonathan Bernstein discussed Non-allergic rhinitis and asthma.

Non-allergic rhinitis (NAR) consists of neurogenic, vasomotor rhinitis, NARES (NAR with eosinophils) and idiopathic endotypes. Idiopathic/neurogenic/vasomotor rhinitis is what we see clinically most commonly and it is difficult to treat.

Consensus definition for NAR is underway - at least 6 sub-phenotypes will be identified, it is still a diagnosis by exclusion. If age over 35 at onset, no family history of allergy, absence of outdoor symptoms in spring and around furred pets, 95% will have NAR.

NAR and AR have equal rates of nasal congestion and post-nasal drip, but rhinorrhea is more common in AR. If you can actually measure nasal cytology on NAR patients you can identify the subtype of NARES, which tends to respond better to therapy. More about NARES here: Nonallergic rhinitis with eosinophilia syndrome and related disorders. http://t.co/aqpiOkAHND

Neuronal pathways possibly determine NAR phenotypes - tachykinins, CGRP and and TRP channels are all being studied. Ipratropium, anticholinergic agent is beneficial in NAR, as is capsaicin, supporting the role of neurogenic pathways in this disease. Azelastine and bepotastine also can engage TRPV1 channels and thus may have benefit in NAR, olopatadine did not, in Bernstein's study.

RADS and RUDS

Irritant-induced asthma is also referred to as reactive airways dysfunction syndrome or RADS, Non-allergic phenotype.

Irritant-induced rhinitis is also thus termed reactive upper airways dysfunction syndrome or "RUDS". Dr Bernstein presented the concept that RUDS and RADS are linked, similar to the one airway hypothesis of AR and allergic asthma.

Small Airways in Asthma

Dr. Kevin Murphy discussed the Importance of the Small Airways in Asthma. Dr Murphy has Chaired the FIT bowl committee for 23 years!

Asthma Insight and Management study (AIM) is a national survey of patients, MDS, RN, and asthma educators in the US. The AIM study showed that rate of assessment of lung function remains low - only 30% of patients had PFTs in the previous year. The AIM study also showed identical rates of hospitalization and ER visits to those reported in the Asthma in America study 10 yrs previously. Although NAEPP guidelines were updated in 2002 and 2007, very little changed over the last 10 yrs in terms of asthma outcomes.

There was a recently described Small Airways Asthma Phenotype: Day and night symptoms, frequent use of SABA/oral steroids and ICS failure.

Of note, it's failure to respond to coarse particle ICS that helps to define small airways asthma. Small airways asthma has a normal FEV1, but abnormalities noted in FEF25-75 and other small airway measurements. Small airway dysfunction is associated with poor asthma control, i.e. normal FEV1, reduced FEF25-75.

Impulse oscillometry measures airway resistance.

Smaller particles can enter smaller airways (common sense). Those with 1.5 micron diameter are termed "highly respirable". Ciclesonide, hFa-beclomethasone, and hFA-flunisolide are the 3 ICS on the market (in the US) in this 1.5 micron range. Of note, HFA-BDP (beclomethasone) is available in a large particle size as well as small particle size.

Great point being made about the extra-fine particle ICS debate - Delivery Device matters!!! Concerns were raised by audience members about the safety of these extra-fine particle ICS products - are they more systemically absorbed? Dr Murphy reiterates the importance of always giving lowest effective dose of ICS, titrate down once control achieved if possible. Here is the link to the "Price" study that generated so many comments at the #ACAAI discussion about extra-fine ICS therapy: http://t.co/vMQ8fFNbZX. The study was QVAR vs. Fostair/Clenil, sponsored by Research in Real-Life Ltd and TEVA Phamaceuticals http://t.co/hx1Pwldj42

This is a Twitter summary from 2014 #ACAAI meeting. The post is a part of series. See the rest here: http://allergynotes.blogspot.com/search/label/ACAAI

The Twitter summary was made possible by @DrAnneEllis

Several allergists did a great job posting updates from the 2014 meeting of the #ACAAI. I used the website “All My Tweets” to review the tweets. For comparison, here are the tweets from previous #ACAAI meetings (scroll down the page for the past years): http://allergynotes.blogspot.com/search/label/ACAAI

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