How do anticholinergics (anticholinergic medications) lead to a false diagnosis of Sjögren's syndrome?

From the Guidelines

Anticholinergic medications can lead to a false diagnosis of Sjögren's syndrome by causing dry mouth and dry eyes, which are the hallmark symptoms of this autoimmune disorder. According to the latest evidence from the 2024 study published in Ophthalmology 1, medications such as antihistamines, tricyclic antidepressants, certain antipsychotics, bladder antispasmodics, and some Parkinson's medications block acetylcholine receptors throughout the body, including those in salivary and lacrimal glands. This blockage reduces secretions, mimicking the glandular dysfunction seen in Sjögren's.

When evaluating a patient with dry eyes and mouth, it's essential to perform a thorough medication review before proceeding with invasive diagnostic tests like lip biopsies or serological testing for anti-SSA/Ro and anti-SSB/La antibodies, as suggested by the study published in Ophthalmology 1. If possible, anticholinergic medications should be discontinued for several weeks to determine if symptoms resolve, which would suggest medication effect rather than true Sjögren's syndrome. The anticholinergic effect is dose-dependent and reversible, unlike the progressive autoimmune damage in true Sjögren's syndrome.

Some key points to consider when evaluating patients with dry eyes and mouth include:

• A high degree of suspicion for Sjögren’s syndrome is appropriate in patients who have clinically significant dry eye and dry mouth symptoms, as noted in the study published in Ophthalmology 1
• A serological examination for anti-Sjögren syndrome A antibody (SSA or anti-Ro), anti-Sjögren syndrome B antibody (SSB or anti-La), rheumatoid factor, and antinuclear antibody should be ordered for patients suspected of having Sjögren’s syndrome, as recommended by the study published in Ophthalmology 1
• New imaging devices, such as placido-ring corneal topographers and meibography, can be used to evaluate the health of the ocular surface, as mentioned in the study published in Ophthalmology 1

Overall, a thorough medication review and consideration of the latest evidence are crucial in evaluating patients with dry eyes and mouth to avoid a false diagnosis of Sjögren's syndrome.

From the Research

Anticholinergics and Sjögren's Syndrome Diagnosis

• Anticholinergics can potentially give a false diagnosis of Sjögren's syndrome due to their side effects, which may mimic the symptoms of the disease 2.
• The use of anticholinergic medications can exacerbate dryness of the mouth and eyes, leading to symptoms similar to those experienced by patients with Sjögren's syndrome 2.
• A study found that 39.1% of patients with Sjögren's syndrome received cholinergic antagonists, which can worsen symptoms and lead to a false diagnosis 2.

Mechanism of False Diagnosis

• Anticholinergics can reduce saliva and tear production, leading to dryness of the mouth and eyes, which are common symptoms of Sjögren's syndrome 2.
• The anticholinergic burden, estimated using the Anticholinergic Drug Scale, can be high in patients with Sjögren's syndrome, leading to an increased risk of false diagnosis 2.
• The presence of anticholinergic medications can make it challenging to diagnose Sjögren's syndrome accurately, as the symptoms may be attributed to the medication rather than the disease itself 3, 2.

Clinical Implications

• Clinicians should be aware of the potential for anticholinergics to give a false diagnosis of Sjögren's syndrome and consider alternative diagnoses in patients taking these medications 2.
• A thorough medical history, including a list of current medications, is essential in diagnosing Sjögren's syndrome accurately 3, 2.
• Further research is needed to understand the relationship between anticholinergics and Sjögren's syndrome diagnosis and to develop effective treatment strategies for patients with this disease 4, 5, 6.