Louis-Charles Malassez

Louis-Charles Malassez (21 September 1842–1909) was a French anatomist and histologist born in Nevers, department of Nièvre.

He studied medicine in Paris, where he worked as an interne from 1867. He served with the 5th Ambulance Corps during the Franco-Prussian War, afterwards returning to Paris, where he worked with distinguished physicians that included Claude Bernard, Jean-Martin Charcot and Pierre Potain. In 1875 he attained the chair of anatomy at Collège de France, and in 1894 became a member of the Académie de Médecine.

Malassez is remembered for research involving histology of the blood, and is credited for design of the hemocytometer, a device used to quantitatively measure blood cells. In the field of dentistry, he described residual cells of the epithelial root sheath in the periodontal ligament. These remaining cells are referred to as epithelial cell rests of Malassez (ERM).

A genus of fungi called Malassezia bears his name. The species in the genus include: Malassezia furfur, Malassezia ovalis, Malassezia pachydermatis, Malassezia sympodialis and Malassezia orbiculare. Malassezia furfur is a lipophilic species that forms on human skin and can cause seborrheic dermatitis and tinea versicolor, Malassezia pachydermatis is a species that is associated with otitis externa in dogs.