Silent reflux, also known as laryngopharyngeal reflux (LPR), can not only cause a variety of airway symptoms but can also aggravate symptoms of airway conditions, such as asthma and pollen allergies.
What is silent reflux?
The term reflux refers mainly to the rising of gastric juice out of the stomach. The acid can irritate the esophagus, thereby causing symptoms such as heartburn.
Reflux can, however, also be gaseous and rise into the throat and airways. Gaseous reflux is acidic and carries along with it pepsin, which can cause a lot of damage. Pepsin is an enzyme from the stomach that is needed for digestion. Once outside the stomach, though, pepsin still performs its digestive functions, thereby damaging the cells of the mucous membranes in the throat and airways.[1]
This kind of reflux is known as silent reflux because it causes unspecific symptoms such as cough and hoarseness.
How silent reflux aggravates other respiratory diseases
Because silent reflux irritates the airways, it can make other respiratory diseases worse.
Aggravation of pollen allergies
The constant irritation of the mucous membranes through pepsin causes inflammation and leads to increased production of mucus.
Pollen allergies also promote mucus production by irritating the mucous membranes. For this reason, it is not surprising that silent reflux can aggravate allergy symptoms such as cough and sniffles.[2]
Aggravation of asthma
The symptoms of silent reflux and asthma resemble each other so closely that silent reflux is frequently misdiagnosed as asthma.[3]
Furthermore, because asthma and silent reflux can both cause an inflammation of the airways, silent reflux can aggravate already-existing asthma.
Silent reflux symptoms are unspecific.
Pollen allergy and asthma are two typical examples of diseases that can be aggravated by silent reflux.
Although all airway conditions can be influenced by silent reflux, silent reflux is often overlooked. However, in combination, the symptoms provide vital clues that help to determine the likelihood of silent reflux being the cause of the symptoms.[4]
One useful tool to find out whether the symptoms point towards silent reflux is the Reflux Symptom Index (RSI). You can determine your score with the help of an online test on Refluxgate.
References
[1] Johnston N, Dettmar PW, Bishwokarma B, Lively MO, Koufman JA. Activity/stability of human pepsin: Implications for reflux attributed laryngeal disease. Laryngoscope 2007;117(6):1036-9.
[2] Alharethy S, Baqays A, Mesallam TA, Syouri F, Al Wedami M, Aldrees T, AlQabbani A. Correlation between allergic rhinitis and laryngopharyngeal reflux. Biomed Res Internat. 2018;ID 2951928.
[3] Koufman, J. IN or OUT? – Asthma that isn’t asthma. The Voice Institute of New York. http://www.voiceinstituteofnewyork.com/in-vs-out-asthma-that-isnt-asthma/. Accessed 11.06.2019.
[4] Belafsky PC, Postma GN, Koufman JA. Validity and reliability of the reflux symptom index (RSI). J Voice. 2002;16(2):274-7.