Antimicrobials in dermatologic surgery: facts and controversies.

The two main uses of antimicrobials in dermatologic surgery include prophylaxis for bacteremia and prevention of localized surgical skin infection (LSSI). Bacteremia can result in hematogenous surgical infections such as infective endocarditis and prosthetic joint infection. Comprehensive guidelines from the American Heart Society (AHA), American Dental Association (ADA), and the American Academy of Orthopedic Surgeons (AAOS) have significantly reduced the number of patients in which prophylaxis is indicated for hematogenous surgical infection. The use of antimicrobials for localized surgical skin infection in dermatology is controversial. Although the overall trend in the literature supports the decreased use of antimicrobials in dermatologic surgery as a whole, it is important to know which situations still warrant antibiotics. This contribution will address the updated guidelines of the AHA, ADA, and AAOS, evidence-based techniques to decrease localized surgical skin infections, and situations in which antibiotics should be considered during dermatologic surgery.

Porokeratosis ptychotropica: a clinically distinct variant of porokeratosis.

Porokeratosis represents a spectrum of clinical disease. Multiple variants have been described including porokeratosis ptychotropica, a rare subtype. The clinical presentation of porokeratosis ptychotropica frequently resembles an inflammatory perianal disease. We report a patient with porokeratosis ptychotropica with coexistent disseminated superficial actinic porokeratosis. We review the current literature on porokeratosis ptychotropica including the clinical presentation, histopathology, cause, and pathogenesis of this rare variant of porokeratosis.

Malignant proliferating pilar tumors arising in KID syndrome: a report of two patients.

We report on two young adults with KID syndrome and follicular hyperkeratosis, hidradenitis suppurativa of the groin, progressive development of proliferative pilar cysts and dissecting cellulitis of the scalp, who developed metastatic malignant pilar tumors. Based on our findings, we believe that cancer surveillance in patients with KID syndrome should include screening for pilar tumors and their early removal to avoid development of malignant proliferating pilar tumors with poor prognosis.

Epidermolysis Bullosa Simplex with mottled pigmentation: mutation analysis in the first reported Hispanic pedigree with the largest single generation of affected individuals to date.

Epidermolysis bullosa simplex with mottled pigmentation (EBS-MP), characterized by trauma-induced blisters, distinct pigmentary changes of the trunk and extremities, and acral hyperkeratotic papules, is almost exclusively caused by a common KRT5 missense mutation affecting the V1 region of keratin 5. We studied the first Hispanic family, the largest single generation of affected family members in which 5 out of 10 siblings inherited EBS-MP from their affected father, as well a second large pedigree, the first reported of Finnish ancestry. In both families, the heterozygous transition mutation 74C-->T of the keratin 5 gene, which results in amino acid substitution P25L, completely co-segregated with the EBS-MP phenotype.

In vivo and in vitro expression of connexins in the human corneal epithelium.

PURPOSE: This study is designed to provide a comprehensive expression profile of connexins in the human corneal epithelium (in vivo) and in cultured primary corneal epithelial cells (PCECs) (in vitro). It also evaluates the pathologic effects of a pathogenic missense mutation in Cx26, which causes keratitis-ichthyosis-deafness syndrome (KIDS), a rare genetic disorder with corneal involvement. METHODS: RT-PCR analysis, immunohistochemistry, and fluorescent dye transfer assays were used to determine the expression pattern and gap junction intercellular communication in PCECs and human cornea. Differentiation-dependent differences in connexin expression of PCECs after a calcium switch were verified by real-time RT-PCR. The common KIDS mutation Cx26(D50N) was studied by determining transient expression in PCECs. RESULTS: In vivo immunostaining revealed widespread and overlapping expression of Cx43 and -30 in the basal and suprabasal layers. Cx26 staining was limited to the lower suprabasal cells, whereas Cx31.1 localized to the apical surface of basal cells in the central cornea and to the lower and middle suprabasal cells in the limbal region. Immunostaining for nine other connexins, including Cx50, was negative. In PCEC, nine connexin genes were detectable by RT-PCR, however, only Cx26, -30, and -43 formed visible gap junction plaques. High-Ca(2+) culture conditions were accompanied by a 1.6- to 2.2-fold upregulation of expression of Cx26, -30, and -43 and a significant increase in gap-junction-mediated dye transfer. Transient expression of mutant Cx26(D50N) in PCECs resulted in cytoplasmic accumulation and lack of gap junction plaque formation and was not altered by coexpression of wild-type (wt)Cx26 or -30. CONCLUSIONS: Gap junction communication in the human corneal epithelium is mediated by Cx26, -30, -31.1, and -43. Poorly differentiated PCECs are uncoupled, and Ca(2+) induced differentiation is associated with an upregulation of connexin expression and intercellular communication. The transfection experiments suggest that KIDS Cx26(D50N) impairs intracellular formation and transport of connexons formed by Cx26 and -30, consistent with a dominant negative effect.

Mutations in GALNT3, encoding a protein involved in O-linked glycosylation, cause familial tumoral calcinosis.

Familial tumoral calcinosis (FTC; OMIM 211900) is a severe autosomal recessive metabolic disorder that manifests with hyperphosphatemia and massive calcium deposits in the skin and subcutaneous tissues. Using linkage analysis, we mapped the gene underlying FTC to 2q24-q31. This region includes the gene GALNT3, which encodes a glycosyltransferase responsible for initiating mucin-type O-glycosylation. Sequence analysis of GALNT3 identified biallelic deleterious mutations in all individuals with FTC, suggesting that defective post-translational modification underlies the disease.