Potential of contrast agents to enhance in vivo confocal microscopy and optical coherence tomography in dermatology: A review.

Distinction between normal skin and pathology can be a diagnostic challenge. This systematic review summarizes how various contrast agents, either topically delivered or injected into the skin, affect distinction between skin disease and normal skin when imaged by optical coherence tomography (OCT) and confocal microscopy (CM). A systematic review of in vivo OCT and CM studies using exogenous contrast agents on healthy human skin or skin disease was performed. In total, nine CM studies and one OCT study were eligible. Four contrast agents aluminum chloride (AlCl) n = 2, indocyanine green (ICG) n = 3, sodium fluorescein n = 3 and acetic acid n = 1 applied to CM in variety of skin diseases. ICG, acetic acid and AlCl showed promise to increase contrast of tumor nests in keratinocyte carcinomas. Fluorescein and ICG enhanced contrast of keratinocytes and adnexal structures. In OCT of healthy skin gold nanoshells, increased contrast of natural skin openings. Contrast agents may improve delineation and diagnosis of skin cancers; ICG, acetic acid and AlCl have potential in CM and gold nanoshells facilitate visualization of adnexal skin structures in OCT. However, as utility of bedside optical imaging increases, further studies with robust methodological quality are necessary to implement contrast agents into routine dermatological practice.

Gallstones are associated with hidradenitis suppurativa: a population-based and hospital-based cross-sectional study from Denmark.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic inflammatory dermatological disease that was recently linked to the metabolic syndrome (MetS). MetS has been associated with gallstones, and nonalcoholic fatty liver has been suggested to be the hepatic expression of MetS. OBJECTIVE: The objective of the study was to investigate whether there was an association of HS with gallstones as well as with hepatic dysfunction. PATIENTS AND METHODS: This was a cross-sectional study comparing a hospital-based HS group, a population-based HS group, and controls for self-reported gallstone and blood sample verified hepatic dysfunction. Blood samples were analyzed for alanine transaminase, bilirubin, alkaline phosphatase, albumin, thrombocytes, and the international normalized ratio. RESULTS: A total of 32 hospital HS patients, 430 population-based HS patients, and 20 780 non-HS controls were identified. The age-sex-smoking-adjusted analysis of gallstones revealed a significant OR of 1.72 (95% CI 1.23-2.42, P=0.0191) and a borderline significant OR of 3.28 (95% CI 1.24-8.74, P=0.0516) for the population HS group and hospital HS group versus controls, respectively. Furthermore, no clinically significant evidence was found with regard to hepatic dysfunction. CONCLUSION: This study demonstrates an association of HS with gallstones, but not with hepatic dysfunction. The association with gallstones may be partly explained by the comorbidity of hypertriglyceridemia and obesity as a part of MetS.