To determine the mean diagnosis delay in patients with MG from Argentina.

Diagnosing myasthenia gravis (MG) can be challenging due to the variability in clinical presentation. Studies in developed countries have identified a diagnosis delay of more than a year in approximately 10% of patients. Data in Latin America is lacking.

A retrospective study was conducted in patients with MG who received treatment in twelve centers. Medical records were reviewed to attain sociodemographic data and disease characteristics. Diagnosis delay (time from symptom onset to diagnosis) was calculated.

172 patients were included. The majority were women (65.1%). The mean age at symptom onset was 43.3 years (SD 21.9), and ocular symptoms were the most frequent (70%) at disease onset. More than half (55.3%) were from the public health system. Neurology was consulted first by the 8.3% of patients.

Mean diagnosis delay was 422.6 (SD 771.5) days, and 24.3% of patients experienced diagnosis delay >1 year. Among patients with >1 year, 29.4% had initially received a different diagnosis and 35.2% were Myasthenia Gravis Foundation of America class III at the time of the diagnosis.

Diagnosis was faster in patients who first consulted a neurologist compared to those evaluated by other specialists (mean 116.5 days vs. 459.1 days; p=0.015). There were no differences between patients evaluated in the public or private health care system.

Although the development of new therapies has advanced in recent years, further efforts are needed in medical education about the disease to improve the diagnosis of MG.