Acquired Hair Disorders
This chapter considers a series of changes of hair due to color (e.g., green hair) or loss (alopecia) including cicatricial (tufted folliculitis) and non-cicatricial (alopecia areata, trichotillomania) forms that occur primarily during childhood and adolescence. We do not consider more common processes that are diagnosed easily, for example, androgenic alopecia or telogen and anagen effluvium. For further information on these processes, readers can consult the textbook by Camacho and co-workers  or the review of Moreno-Romero and Grimalt . Deficient hair losses caused by nutritional or metabolic disorders are not addressed either. Finally, the descriptions include infrequent clinical patterns such as alopecia parvimaculata and bird’s nest hair.