Proton Pump Inhibitors Theory

[Guide]

Diagram depicting the major determinants of gastric acid secretion, with inclusion of drug targets for peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD). Image courtesy of Wikimedia Commons. 

Proton Pump Inhibitors Theory
One of the systemic cormorbidities in rosacea is the use of Proton Pump Inhibitors (PPIs).

What are PPIs? 

"Proton-pump inhibitors (PPIs) are members of a class of medications whose main action is a profound and prolonged reduction of stomach acid production." [1] These include omeprazole, lansoprazole and the antibiotics clarithromycin and amoxicillin.

Why are they called proton pump inhibitor?

"They are called 'proton pump inhibitors' because they work by blocking (inhibiting) a chemical system called the hydrogen-potassium adenosine triphosphatase enzyme system (otherwise known as the 'proton pump'). This chemical system is found in the cells in the stomach lining that make stomach acid." [2]

What do PPIs do that is related to causing rosacea? 

One of the related rosacea theories is the Low Gastric Acid and Rosacea which has been around for sometime now, back to a paper in 1931 by Epstein and Susnow. [3] 

PPIs inhibit gastric acid production. 

What happens in the stomach without a doubt is related to what happens in the gut. There are a number of rosacea theories related to the gut, i.e, IBD and Rosacea, IBS and Rosacea,  SIBO and Rosacea, and Rosacea and the Gut. GUT Rosacea is listed as a variant of rosacea. H Pylori (Helicobacter Pylori) in the gut has been a subject of investigation with rosacea for sometime now and continues to be investigated in clinical papers. 

Antibiotics have been the mainstay of medical treatment for rosacea, particularly those medicines derived from tetracycline, i.e., doxycycline, which work in the gut and has an effect on the stomach and bowel microbiota. The vast majority of rosacea patients have taken antibiotics, usually high dose for a significant period of time or low dose for even much longer periods. There is evidence that PPIs may even contribute to antibiotic resistance. [4]

PPIs Systemic Cormorbidity in Rosacea Related to Gastric Acid Reduction
One paper concluded, "In conclusion, prolonged PPI use was associated with an increased risk of rosacea, particularly in women and patients with peptic ulcers." [5]

Theory
Therefore, the theory that the use of PPIs may have a relationship in causing rosacea. Obviously not all rosacea sufferers have used PPIs so this is just one theory among the long list. For example, one theory is that rosacea is caused by demodex mites, but not all rosacea sufferers have any increase in demodex mites and treatment for demodex doesn't improve the rosacea, nevertheless, the theory is still listed since some rosacea sufferers respond well to treatment for demodectic rosacea. Ergo, the PPI and rosacea theory stands. A theory. 

End Notes

[1] Proton-pump inhibitors, Wikipedia

[2] Proton Pump Inhibitors, Dr Laurence Knott, Patient

[3] Cal West Med. 1931 Aug;35(2):118-20.
ACNE ROSACEA: WITH PARTICULAR REFERENCE TO GASTRIC SECRETION.
Epstein N, Susnow D.
ACNE_ROSACEA_GASTRIC_SECRETION_Hypochlorhydria_Acid_Epstein_1931.pdf 

[4] JAMA Intern Med 2020 Feb 24
Does Gastric Acid Suppression Encourage Antibiotic Resistance?
Abigail Zuger, MD reviewing Willems RPJ et al. JAMA Intern Med 2020 Feb 24 Lee TC and McDonald EG. 

J Clin Microbiol. 2005 Jul; 43(7): 3059–3065.doi: 10.1128/JCM.43.7.3059-3065.2005
Effect of pH and Antibiotics on Microbial Overgrowth in the Stomachs and Duodena of Patients Undergoing Percutaneous Endoscopic Gastrostomy Feeding
Graeme A. O'May, Nigel Reynolds, Aileen R. Smith, Aileen Kennedy, and George T. Macfarlane

[5] J Dermatol. 2020 Jul 01;:
Use of proton pump inhibitors and risk of rosacea: A nationwide population-based study.
Dai YX, Tai YH, Chen CC, Chang YT, Chen TJ, Chen MH