In 1889 he was appointed chef de service (department head) at the Hôpital Lourcine, afterward working at the Hôpital Saint-Louis, where he remained until 1916.
He studied exotic diseases in his travels throughout Asia.
Beurmann is known for his contributions in the study of sporotrichosis, a disease that was fairly common in Europe at the time.
The fungus that causes sporotrichosis was earlier identified by American physician Benjamin Robinson Schenck (1873-1920) and was named Sporothrix schenckii in Schenck's honor.
Beurmann did extensive research involving the cutaneous aspects of the disease, and with Henri Gougerot (1881-1955), he published the monograph, Les Sporotrichoses, a treatise that was based on 250 cases of sporotrichoses in France.
In 1903 dermatologist Raymond Sabouraud (1864-1938) suggested to Beurmann, the use of potassium iodide as a remedy.
Because of Beurmann's thorough research of sporotrichosis, Sporothrix schenckii was sometimes referred to as Sporotrichum beurmanni.