Association of Postoperative Antibiotics With Surgical Site Infection in Mohs Micrographic Surgery.

BACKGROUND: Surgical site infection (SSI) is the most frequent complication of Mohs micrographic surgery. Previous studies have identified risk factors for SSI, but it is not known whether antibiotic prophylaxis mitigates this risk. OBJECTIVE: To measure the association between antibiotic prophylaxis and SSI in a convenience sample of Mohs cases and to report on the utility of propensity scoring to control for confounding by indication in registry data. METHODS: Data were drawn from a pilot quality improvement registry of 816 Mohs cases. The relationship between antibiotic prophylaxis and SSI was assessed with logistic regression modeling using propensity score methods to adjust for confounding. RESULTS: One hundred fifty-one cases were prescribed antibiotic prophylaxis (18.5%). Of 467 cases with follow-up, 16 (3.4%) developed SSI. Infection rates were higher in subjects prescribed prophylaxis, but propensity adjustment reduced this effect. Adjusted odds of infection were 1.47-fold higher in subjects prescribed antibiotics and not statistically significant (95% confidence interval 0.29-7.39; p = .64). CONCLUSION: Although there was no significant difference in SSI among patients prescribed prophylactic antibiotics, statistical precision was limited by the low incidence of infection. Larger population-based prospective registry studies including propensity adjustment are needed to confirm the benefit of prophylactic antibiotics in high-risk surgical cases.

Proliferative activity in melanocytic nevi from patients grouped by age with clinical follow-up.

Any mitotic activity in a melanocytic nevus is a source of concern about the biologic potential of that lesion, especially in an adult. Previously diagnosed benign melanocytic nevi in individuals from six different age groups were re-examined; mitotic figures were counted in routine hematoxylin and eosin-stained sections; Ki-67 nuclear positivity was assessed by immunohistochemistry. Mitoses were seen in 0-14.3% of nevi in all groups of patients >1 year of age; 55.6% (5/9 cases) of nevi in patients <1-year old had mitoses identified histologically. Ki-67-positive melanocytes were seen in all cases of those lesions in infants (less than 1-year old) and only in a minority of lesions from the other age groups. The maximum and mean numbers of Ki-67-positive melanocytes per square millimeter were highest in patients <1-year old (16.7 and 5.6, respectively), and decreased in all other groups. Follow-up data were available in the majority of the patients. There were no examples of malignant melanoma in the various age groups. We conclude that proliferative activity in benign melanocytic nevi decreases with age, however, proliferative activity can be seen at any age and its significance must be judged in the context of other histopathologic features.

The role of IL-17 in psoriasis.

BACKGROUND: Psoriasis is a chronic skin condition traditionally believed to involve the Th1 pathway. Recently, the IL-23/Th17/IL-17 pathway has been highlighted in the pathogenesis of psoriasis and other autoimmune inflammatory conditions. From a clinician's perspective, we sought to review the basic science data relevant to IL-17's role in psoriasis pathogenesis. METHODS: We performed a Pubmed and Web of Knowledge search for English articles starting from 1990 that discussed the Th17 pathway. Search terms such as "IL-17" and "psoriasis" were utilized. RESULTS: The IL-17 pathway is regulated by IL-23, a cytokine that is vital for the expansion and maintenance of the Th17 cell population. Th17 derived cytokines (IL-17A, IL-17F, IL-17A/F and IL-22) were elevated in both psoriasis-like murine models and human psoriatic lesional biopsies. Ixekizumab (anti-IL-17A) treatment of psoriasis was found to normalize levels of IL-17 downstream gene products. CONCLUSION: Both preclinical and clinical studies support the central role of IL-17 in the pathogenesis of psoriasis.

Biologic therapy in erythrodermic and pustular psoriasis.

BACKGROUND: The efficacy of biologic therapy in treating plaque-type psoriasis is well documented. However, there is less data for use in other psoriasis subtypes, such as erythrodermic and generalized pustular psoriasis. OBJECTIVE: We sought to review the safety and efficacy of biologic medications in the treatment of these severe subtypes of psoriasis and to identify strategies to help clinicians optimally manage these patients. METHODS: We searched Pubmed for English language literature that assessed the use of biologic medication to treat erythrodermic or generalized pustular psoriasis. RESULTS: The primary literature included cases reports, cases series, and open-label, uncontrolled trials. There were no head-to-head studies or other controlled trials. In both erythrodermic and generalized pustular psoriasis, infliximab was used to treat over half of the reported cases. Other biologic medications that were successfully used included etanercept, ustekinumab, adalimumab, and anakinra. Most cases reported improvement with biologic therapy. Serious adverse events were reported in 10-12% of the patients. CONCLUSION: Although the evidence is limited, biologic therapy appears to be effective in treating erythrodermic and generalized pustular psoriasis. In order to assess the comparative efficacy and safety of the biologic medications, larger controlled studies are needed.

Memory regulatory T cells reside in human skin.

Regulatory T cells (Tregs), which are characterized by expression of the transcription factor Foxp3, are a dynamic and heterogeneous population of cells that control immune responses and prevent autoimmunity. We recently identified a subset of Tregs in murine skin with properties typical of memory cells and defined this population as memory Tregs (mTregs). Due to the importance of these cells in regulating tissue inflammation in mice, we analyzed this cell population in humans and found that almost all Tregs in normal skin had an activated memory phenotype. Compared with mTregs in peripheral blood, cutaneous mTregs had unique cell surface marker expression and cytokine production. In normal human skin, mTregs preferentially localized to hair follicles and were more abundant in skin with high hair density. Sequence comparison of TCRs from conventional memory T helper cells and mTregs isolated from skin revealed little homology between the two cell populations, suggesting that they recognize different antigens. Under steady-state conditions, mTregs were nonmigratory and relatively unresponsive; however, in inflamed skin from psoriasis patients, mTregs expanded, were highly proliferative, and produced low levels of IL-17. Taken together, these results identify a subset of Tregs that stably resides in human skin and suggest that these cells are qualitatively defective in inflammatory skin disease.

Biologic fatigue in psoriasis.

BACKGROUND: Over the past 15 years, biologic medications have greatly advanced psoriasis therapy. However, these medications may lose their efficacy after long-term use, a concept known as biologic fatigue. We sought to review the available data on biologic fatigue in psoriasis and identify strategies to help clinicians optimally manage patients on biologic medications in order to minimize biologic fatigue. METHODS: We reviewed phase III clinical trials for the biologic medications used to treat psoriasis and performed a PubMed search for the literature that assessed the loss of response to biologic therapy. RESULTS: In phase III clinical trials of biologic therapies for the treatment of psoriasis, 20-32% of patients lost their PASI-75 response during 0.8-3.9 years of follow-up. A study using infliximab reported the highest percentage of patients who lost their response (32%) over the shortest time-period (0.8 years). Although not consistently reported across all studies, the presence of antidrug antibodies was associated with the loss of response to treatment with infliximab and adalimumab. CONCLUSION: Biologic fatigue may be most frequent in those patients using infliximab. Further studies are needed to identify risk factors associated with biologic fatigue and to develop meaningful antidrug antibody assays.

Psychodermatology: an overview.

Psychodermatology is an interface between dermatology and psychiatry. The different disorders within psychodermatology can be categorized in 2 ways: by the type of psychodermatologic disorder or by the underlying psychiatric disorder. The types of psychodermatologic disorders include psychophysiological, primary psychiatric, secondary psychiatric, and cutaneous sensory disorder. The psychiatric disorders include anxiety, depression, obsessive-compulsive disorder, and psychosis. This manuscript gives an overview of the different psychodermatologic disorders, underlying psychiatric disorders, and how to manage psychodermatology cases.

Delusions of parasitosis.

The most common monosymptomatic hypochondriacal psychosis encountered by a dermatologist is delusions of parasitosis. In this condition, patients have an "encapsulated" fixed, false belief that they are infested with parasites or have foreign objects extruding from their skin. The patient will often experience feelings of biting, crawling and stinging related to the delusion. Most patients do not have other major psychiatric problems outside of their encapsulated delusion. The patient usually presents with a long history of symptoms and multiple visits to physicians in more than one specialty. Without an informed approach to these patients that focuses on the development of therapeutic alliance, clinical interactions can become very unpleasant. However, when treated with pimozide, risperidone, or other antipsychotic medications, patients have a very high response rate. Therefore, it is important for dermatologists to be able to handle these cases and know that the development of the therapeutic alliance is the key step to successful management.