Faculty Bibliography

Necrolytic acral erythema is a rare, cutaneous manifestation of hepatitis C virus infection that is characterized by erythematous, violaceous or dusky papules, blisters, and/or erosions in the early stages and by well-demarcated, hyperkeratotic, targetoid plaques with a peripheral rim of macular erythema, secondary lichenification and hyperpigmentation, and overlying fine micaceous or necrotic-appearing scale in the later stages. Because most topical modalities prove ineffective, treatment of the underlying viral infection or therapeutic zinc supplementation are required for clinical improvement.

Silicone in liquid and gel implantation may induce granuloma formation and migration. Although there are many complications associated with solid silicone implantation, there have been no published reports of distant granuloma formation. We present a case of a woman with clinical and serologic findings that are consistent with systemic lupus erythematosus and a histopathologic diagnosis of foreign body granulomatous dermatitis 20 years after solid silicone nasal implantation. We review the literature on silicone granulomas and their treatment and speculate on the potential etiologies of a challenging case presentation.

Adenosine has an important role in inflammation and tissue remodeling and promotes dermal fibrosis by adenosine receptor (A2AR) activation. Adenosine may be formed intracellularly from adenine nucleotides or extracellularly through sequential phosphohydrolysis of released ATP by nucleoside triphosphate diphosphohydrolase (CD39) and ecto-5'-nucleotidase (CD73). Because the role of these ecto-enzymes in fibrosis appears to be tissue specific, we determined whether these ectonucleotidases were directly involved in diffuse dermal fibrosis. Wild-type and mice globally deficient in CD39 knockout (CD39KO), CD73 (CD73KO), or both (CD39/CD73DKO) were challenged with bleomycin. Extracellular adenosine levels and dermal fibrosis were quantitated. Adenosine release from skin cultured ex vivo was increased in wild-type mice after bleomycin treatment but remained low in skin from CD39KO, CD73KO, or CD39/CD73DKO bleomycin-treated mice. Deletion of CD39 and/or CD73 decreased the collagen content, and prevented skin thickening and tensile strength increase after bleomycin challenge. Decreased dermal fibrotic features were associated with reduced expression of the profibrotic mediators, transforming growth factor-beta1 and connective tissue growth factor, and diminished myofibroblast population in CD39- and/or CD73-deficient mice. Our work supports the hypothesis that extracellular adenosine, generated in tandem by ecto-enzymes CD39 and CD73, promotes dermal fibrogenesis. We suggest that biochemical or biological inhibitors of CD39 and/or CD73 may hold promise in the treatment of dermal fibrosis in diseases such as scleroderma.