To the Editor.—
I quite agree with Zitelli,1 who reported in the June 1986 issue of the Archives that the microscopic appearance of what has been termed pseudomonilethrix can be perfectly duplicated by compression of some scalp hairs between two glass microscope slides. I have observed this occurrence in several instances, calling it (to myself) "compressible hair." One of these instances has been noted in association with a forthcoming case presentation of a new hair abnormality by Brown et al.2 Since first observing the phenomenon several years ago in hair from a patient of Joe Jorrizo, MD, then in Galveston, Tex, I have purposely exerted pressure on hair samples between two glass slides, hoping that "compressible hair" might turn out to be a simple measure of underlying pathology or structural weakness, perhaps cosmetic in origin. Most samples that were compressible required considerable pressure to cause the characteristic indentations at points of crossing; those few that compressed easily tended to be from hair with other kinds of shaft abnormalities, or from individuals using considerable cosmetic measures.
Crounse RG. Artifactual Production of Pseudomonilethrix. Arch Dermatol. 1987;123(5):563. doi:10.1001/archderm.1987.01660290027002