Trends in Diagnosing Alopecia with Scalp Biopsy & Trichoscopy: A Review of the Literature

Summary: Hair loss is a common problem among patients who present to their dermatologist. Diagnosis in the hair clinic often includes a thorough history, clinical examination with trichoscopy, and a potential scalp biopsy. Over the past few decades, there has been much debate on the reliability of one technique over the other. As a result, this review paper aims to assess the trends and development of trichoscopy and the utilization of scalp biopsy in dermatologic practice. Literature search using keywords “Trichoscopy”, “alopecia”, “scalp biopsy”, “hair loss” was done in Pubmed, Ovid MEDLINE, and Cochrane. The search yielded 138 articles After title, abstract, in-text review and removing duplicates, 53 articles were included. Specifically, the literature search demonstrated a trend in the relationship between scalp biopsy and trichoscopy in diagnosing scalp disorders, especially alopecia, from late 1950s to present. From the late 1950s - mid 2000s, scalp biopsy is the gold standard for scalp disorders/alopecia diagnosis. From the mid 2000s - mid 2010s, trichoscopy became popular and was speculated to replace scalp biopsy. From 2016 until now, scalp biopsy is reinforced as the ultimate diagnostic tool, and trichoscopy is valuable in aiding diagnosis. In conclusion, scalp biopsy and trichoscopy are both essential diagnostic aids. Dermatologists and pathologists in training should be competent in performing both techniques and interpreting the results of both techniques.