Monilethrix is a genetic disorder characterized by a beaded appearance to the hair from periodic thinning and swelling of the hair shaft. It is a type of dysplasia, which refers to the abnormal growth of tissue, that affects the hair and that may result in hair loss.
The condition presents itself at birth or shortly thereafter as alopecia in the occipital area (back) of the scalp that gradually extends to the rest of the scalp. It is accompanied by erythema (a reddening of the skin) and follicular hyperkeratosis (the thickening of the outer sheaths of the follicles) that results in a rough feeling on the scalp. The condition may also affect other hairy areas, including the eyebrows, eyelashes, pubic areas, armpits and body hair. Affected hairs may appear beaded and constricted to a length of a few millimeters, though this varies from patient to patient.
A variation of monilethrix, called moniliform hair syndrome, may also include nail alterations as well as other possible ectodermal (pertaining to the outermost layers of cells) defects with neurological, dental or ophthalmologic alterations.
Drug treatment is possible for cases of monilethrix, though the best treatment is found in avoiding the mechanical actions of combing and brushing. As always, symptoms seeming to pertain to this condition should be discussed with a medical professional.