Achalasia is a relatively rare condition, with an estimated incidence between 0.4 and 1.1 in 100,000 and a prevalence of 7.9 to 12.6 per 100,000 population. Affecting the oesophagus muscles - the tube that carries food from the mouth to the stomach. People with this disorder have difficulty swallowing food and liquid, often feel like food is stuck in their throat, and may suffer from chest pain and excessive weight loss. This happens because the lower oesophageal sphincter, a muscle at the bottom of the oesophagus, fails to relax properly to let food pass into the stomach.

While the exact cause of achalasia is unknown, it has traditionally been thought of as an autoimmune disease that damages the oesophagal myenteric neurons.

However, a novel hypothesis suggests that achalasia might sometimes be driven by allergies, specifically a variant of Eosinophilic Oesophagitis (EoE). This could result from eosinophils and/or mast cells infiltrating the oesophageal muscle and releasing substances that interfere with muscle movement and harm neurons. 

A recent study published in Clinical Gastroenterology and Hepatology sought epidemiological evidence to support this theory by studying the frequency of EoE and other allergic disorders among achalasia patients in the Utah Population Database.


Researchers utilised International Classification of Diseases codes to find patients with achalasia and allergic disorders, including EoE, asthma, atopic dermatitis, contact dermatitis, allergic rhinitis, allergic conjunctivitis, hives/urticaria, and anaphylaxis. The relative risk (RR) for each allergic disorder was calculated by comparing the frequency among achalasia patients to that in individuals matched for birth year and sex. A further subanalysis was performed for patients aged 40 or younger and those older than 40.


The study identified 844 patients with achalasia, and it was found that nearly half of them (47.6%) had at least one allergic disorder. Interestingly, EoE was diagnosed in 6.5% of achalasia patients - a rate far higher than expected, resulting in a RR of 32.9. This association was even stronger among younger patients (age ≤40), where the RR for EoE rose to an astounding 69.6. All other examined allergic disorders showed significantly increased RRs, almost triple the general population's rates.


The study reveals a strong association between achalasia, EoE, and other allergic disorders, supporting the theory that achalasia might sometimes be an allergic condition. This discovery could pave the way for new perspectives in understanding and treating achalasia.

For our eosinophilic community, we might look at potential new ways to manage or prevent achalasia and monitor both conditions. By understanding its connection to allergic disorders, we could fine-tune our approach towards treatment, focusing not just on the symptoms of achalasia but also its potential allergic causes.

This research is a step towards better health outcomes for those with achalasia and related disorders.

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