Cross-reacting allergens between fish, shellfish, arachnids, and insects

The increased consumption of fish and shellfish has resulted in more frequent reports of adverse reactions to seafood.

Cross-reactivity is a problem

Potential cross-reacting allergens have been identified within the fish family and between shellfish, arachnids, and insects.

Prick-to-prick tests may be needed

The diagnostic approach may require prick-to-prick tests using crude extracts of both raw and cooked forms of seafood for screening seafood sensitization. This approach may be required before a food challenge or where food challenge is not feasible.

Different epitopes may explain different disease severity

IgE antibodies from individuals with persistent allergy may be directed against different epitopes than those in patients with transient allergy.

Mutated proteins as future immunotherapy

Mutated less allergenic seafood proteins have been developed for allergen-specific immunotherapy but this approach is still experimental and not ready for prime time.

References:

Fish and shellfish allergy in children: Review of a persistent food allergy. Tsabouri S, Triga M, Makris M, Kalogeromitros D, Church MK, Priftis KN. Pediatr Allergy Immunol. 2012 May 3. doi: 10.1111/j.1399-3038.2012.01275.x. [Epub ahead of print]
http://www.ncbi.nlm.nih.gov/pubmed/22554093?dopt=Abstract

Image source: Gadus morhua, Atlantic cod. Wikipedia, public domain.

Comments from Twitter:

Dr. Ellis @DrAnneEllis: Crustaceans are the "bugs of the sea"

Prescribing inhaled steroid during ED visit for asthma decreases admissions, saves $7k per 100 patients

This cost-effectiveness analysis compared 3 ED-based inhaled corticosteroid (ICS) delivery options:

- usual care (recommending outpatient follow-up)
- prescribe (uniformly prescribing ICS)
- dispense (uniformly dispensing ICS)

Rates of ED relapse visits and hospitalizations within 1 month of ED visit were compared across all 3 arms.

Rate of return to ED per 100 patients within 1 month of the ED visit was 10 visits for the usual care arm, 9 visits for the prescription arm, and 8 visits for the medication-dispensing arm. Rates of hospitalization per 100 patients were 2.4, 2.2, and 1.9, respectively.

Including indirect costs related to missed parental work, total costs per 100 patients were $27,100, $22,000, and $20,100, respectively. Total cost savings per 100 patients comparing the usual care arm with the medication dispensing arm was $7000.

This study suggests that uniform prescribing or dispensing of ICS at the time of ED visit for asthma may lead to a decreased number of ED visits and hospital admissions within 1 month and provides substantial cost-savings.



Asthma Inhalers (click to enlarge the image).

References:

A Cost-Effectiveness Analysis of Inhaled Corticosteroid Delivery for Children with Asthma in the Emergency Department. Annie Lintzenich Andrews, et al. The Journal of Pediatrics, Volume 161, Issue 5 , Pages 903-907.e1, November 2012
http://www.jpeds.com/article/PIIS002234761200532X/abstract

Image source: Image source: FDA and Wikipedia, public domain.

Auvi-Q inventors -- twins with food allergies -- profiled by CNN

From CNN:

Evan and Eric Edwards have life-threatening allergies and wanted to develop a better way to deliver epinephrine, a drug used to treat serious allergic reactions. Their vision started shortly after graduating from high school and became a reality 15 years later. About a month after Auvi-Q's launch, a mother described how her daughter had a severe allergic reaction. She described how Auvi-Q helped her by "having a voice walking through the steps in an emergency situation." In her opinion, Auvi-Q saved her daughter's life.

References: Twins create life-saving allergy device - CNN.com http://bit.ly/10HKplg

How to use a metered dose inhaler (MDI) - CDC teaching videos

Using a metered dose inhaler with a spacer:



Using a metered dose inhaler (inhaler in mouth):



Using a metered dose inhaler one to two inches from mouth:

Inhaled steroids at high doses may cause adrenal insufficiency

Adrenal insufficiency is a potential complication of therapy with inhaled corticosteroids (ICS). Previous studies found the highest risk of adrenal insufficiency with fluticasone. This study reexamined the relationship between the use of ICS and adrenal insufficiency by using a cohort of patients treated for respiratory conditions during 1990-2005 in Quebec, Canada, with follow-up until 2007.

Cases of adrenal insufficiency were matched with up to 10 controls. 392 cases were identified (incidence rate=1/10,000 person-years). The rate of adrenal insufficiency was not significantly higher among all current users of ICS. However, patients receiving the highest dosages showed a greater risk (OR=1.84).

Inhaled corticosteroids at high doses appear to be a significant independent risk factor for adrenal insufficiency. Physicians prescribing ICS at higher doses should be aware of the signs and symptoms of adrenal insufficiency in their patients.



Asthma Inhalers (click to enlarge the image).

References:

The use of inhaled corticosteroids and the risk of adrenal insufficiency. Lapi F, Kezouh A, Suissa S, Ernst P. Eur Respir J. 2012 Oct 11. http://www.ncbi.nlm.nih.gov/pubmed/23060630