Faculty Bibliography

Hair loss (alopecia) is a common problem and is often a major source of distress for patients. The differential diagnosis of alopecia includes both scarring and nonscarring alopecias. In addition, many hair shaft disorders can produce hair shaft fragility, resulting in different patterns of alopecia. Therefore, an organized and systematic approach is needed to accurately address patients' complaints to achieve the correct diagnosis. Part 1 of this 2-part continuing medical education article on alopecia describes history taking and the clinical examination of different hair loss disorders. It also provides an algorithmic diagnostic approach based on the most recent knowledge about different types of alopecia.

The use of trichoscopy for evaluating a number of hair and scalp disorders is gaining popularity. It is a simple and noninvasive in vivo tool for visualizing hair shafts and the scalp. Recently, alopecias have been classified according to their trichoscopic findings. The second part of this 2-part continuing medical education article reviews recent advances in this field and describes a systematic approach for using the differential diagnostic findings of trichoscopy in alopecia.

Treatment of alopecia areata is dependent on age of patient as well as the extent and duration of scalp involvement. Treatments include steroids, topical immunotherapy, topical minoxidil, anthralin, and immunosuppressants. Each case must be dealt with on a customized individual basis.

Dissecting cellulitis of the scalp is a chronic, relapsing, inflammatory disease of the scalp that results in scarring alopecia. We present a case of a 32-year-old man with recalcitrant disease who is now responding to treatment with isotretinoin. The pathogenesis, clinical presentation, disease associations, and histopathological findings are reviewed. Treatment can be challenging. The literature on medical and surgical therapeutic options is reviewed.

We conducted a microarray study to discover gene expression patterns associated with a lack of melanogenesis in non-pigmented hair follicles (HF) by microarray. Pigmented and non-pigmented HFs were collected and micro-dissected into the hair bulb (HB) and the upper hair sheaths (HS) including the bulge region. In comparison to pigmented HS and HBs, nucleotide excision repair (NER) family genes ERCC1, ERCC2, ERCC3, ERCC4, ERCC5, ERCC6, XPA, NTPBP, HCNP, DDB2 and POLH exhibited statistically significantly lower expression in non- pigmented HS and HBs. Quantitative PCR verified microarray data and identified ERCC3 as highly differentially expressed. Immunohistochemistry confirmed ERCC3 expression in HF melanocytes. A reduction in ERCC3 by siRNA interference in human melanocytes in vitro reduced their tyrosinase production ability. Our results suggest that loss of NER gene function is associated with a loss of melanin production capacity. This may be due to reduced gene transcription and/or reduced DNA repair in melanocytes which may eventually lead to cell death. These results provide novel information with regard to melanogenesis and its regulation.