[How I explore... Hair loss in cancer patients].

Increased hair loss followed, in some instances by an acute focal or total alopecia, can develop in some cancer patients. The surgical stress or procedure, radiotherapy and some chemotherapy regimens can be responsible for these disturbing events. The alopecia is transient or permanent according to its origin. Diverse diagnostic and prognostic methods are available for assessing alopecias. The trichogram is a rewarding one.