Role of trichoscopy in children's scalp and hair disorders.

Hair and scalp disorders in children may originate from the hair itself, scalp skin, or infectious causes and be congenital or acquired. The most common sign is alopecia, frequently brought on by tinea capitis, patchy alopecia areata, or trichotillomania. Sometimes less frequent and clinically more elusive conditions such as initial androgenetic alopecia, congenital triangular alopecia, or alopecia areata incognita may be responsible for hair loss. The noninvasive technique known as trichoscopy is being used more frequently, aiding in the prompt differential diagnosis and follow-up of many of these diseases, oftentimes providing further examination before a treatment decision is made. This review of trichoscopy of the main scalp and hair disorders afflicting children and adolescents discusses the most important dermoscopic criteria and the usefulness of this technique.