Faculty Bibliography

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.

BACKGROUND: Basal cell carcinoma (BCC) is the most common malignancy in humans worldwide. Studies suggest that BCCs exhibit immunoprotection, similar to other keratinocyte carcinomas, although the mechanisms of defence have not been defined. OBJECTIVES: To examine if indoleamine 2,3-dioxygenase (IDO), an immune privilege-associated enzyme, would be expressed in BCC, regulated in part by CXCR3. METHODS: We analysed the expression and function of IDO in human BCC (hBCC) tissues using nonlesional skin epithelial (NL) tissues as a control. RESULTS: Quantitative real-time reverse transcription-polymerase chain reaction (qPCR) revealed significant upregulation of IDO1 and IDO2 (12.5- and 19.14-fold change, respectively) in nodular hBCCs as compared with NL tissues. Immunohistochemistry showed that IDO colocalized with keratin 17, a BCC keratinocyte marker, in hBCC tissues. Western blot identified a full-length IDO (42 kDa) product and a splice variant ( approximately 30 kDa) in BCC tissues. Kynurenine assays and qPCR were conducted to determine IDO enzymatic activity in hBCCs in vitro with CXCL11 supplementation, which has previously been shown to be required for the tumour cell growth. Addition of CXCL11 upregulated IDO2 and increased l-kynurenine concentration in a dose-dependent manner in hBCCs while normal primary keratinocytes exhibited no response. Conclusions: The expression of IDO at both mRNA and protein levels in hBCC tissues, the upregulation of IDO2 and the IDO-mediated l-kynurenine production in hBCCs with CXCL11 treatment suggest that functional IDO is synthesized by hBCC tumours and may be used as a method of immunoprotection during tumorigenesis. Also, IDO enzymatic activity may be modulated by CXCR3/CXCL11 signalling in BCCs.

BACKGROUND: We report on a first case of lichen planopilaris (LPP) mimicking androgenetic alopecia (AGA) in an individual who has been break-dancing on his head for many years. LPP is an autoimmune inflammatory scalp condition that when left untreated can result in scarring and irreversible hair loss. The etiology of LPP is unknown. Different treatment modalities are used for LPP and AGA. OBJECTIVE: To increase the awareness of physicians to the possibility of scarring hair loss (LPP) presenting like AGA. RESULTS: Scalp examination showed scarring patches of hair loss. A scalp biopsy confirmed the diagnosis of LPP. CONCLUSION: Chronic scalp trauma due to break dancing may be a trigger for LPP. A meticulous scalp examination should be performed before making a diagnosis of nonscarring conditions of hair loss such as AGA. Early recognition of LPP and appropriate treatment are important before scarring and irreversible hair loss ensue.

BACKGROUND: Although central scalp hair loss is a common problem in African American women, data on etiology or incidence are limited. OBJECTIVE: We sought to determine the frequency of various patterns and degree of central scalp hair loss in African American women and to correlate this with information on hair care practices, family history of hair loss, and medical history. METHODS: Five hundred twenty-nine subjects at six different workshops held at four different sites in the central and/or southeast United States participated in this study. The subjects' patterns and degree of central scalp hair loss were independently assessed by both subject and investigator using a standardized photographic scale. Subjects also completed a detailed questionnaire and had standardized photographs taken. Statistical analysis was performed evaluating answers to the questionnaire relative to pattern of central hair loss. RESULTS: Extensive central scalp hair loss was seen in 5.6% of subjects. There was no obvious association of extensive hair loss with relaxer or hot comb use, history of seborrheic dermatitis or reaction to a hair care product, bacterial infection, or male pattern hair loss in fathers of subjects; however, there was an association with a history of tinea capitis. LIMITATIONS: There was no scalp biopsy correlation with clinical pattern of hair loss and further information on specifics of hair care practices is needed. CONCLUSIONS: This central scalp photographic scale and questionnaire provide a valid template by which to further explore potential etiologic factors and relationships to central scalp hair loss in African American women

Basal cell carcinoma (BCC) is the most common skin malignancy encountered worldwide. We hypothesized that CXC chemokines, small cytokines involved in inducing directed leukocyte chemotaxis, could play a key role in the modulation of BCC growth. In this study, quantitative RT-PCR revealed that the chemokines CXCL9, 10, 11, and their receptor CXCR3 were significantly upregulated by an average 22.6-fold, 9.2-fold, 26.6-fold, and 4.9-fold, respectively in BCC tissue samples as compared with nonlesional skin epithelium. Immunohistochemistry analysis revealed that CXCR3, CXCL10, and CXCL11, but not CXCL9, colocalized with cytokeratin 17 (K17) in BCC keratinocytes. In addition, CXCR3 and its ligands were expressed in cells of the surrounding BCC stroma. The chemokines and K17 were also expressed in cultured human immortalized HaCaT keratinocytes. Exposure of HaCaT cells or primary BCC-derived cells to CXCL11 peptides in vitro significantly increased cell proliferation. In primary BCC-derived cell cultures, addition of CXCL11 progressively selected for K17+/CXCR3+ co-expressing cells over time. The expression of CXCR3 and its ligands in human BCC keratinocytes, the enhancement of keratinocyte cell proliferation by CXCL11, and the homogeneity of K17+ BCC cells in human BCC-isolated cell population supported by CXCR3/CXCL11 signaling all suggest that CXCR3 and its ligands may be important autocrine and/or paracrine signaling mediators in the tumorigenesis of BCC.