Allergy - 5: Allergy and the skin: eczema and chronic urticaria

Eczema is common, occurring in 15%-20% of infants and young children. For some infants it can be a severe chronic illness with a major impact on the child's general health and on the family. A minority of children will continue to have eczema as adults. The exact cause of eczema is not clear, but precipitating or aggravating factors may include food allergens (most commonly, egg) or environmental allergens/irritants, climatic conditions, stress. and genetic predisposition. Management of eczema consists of education; avoidance of triggers and allergens; liberal use of emollients or topical steroids to control inflammation; use of antihistamines to reduce itch; and treatment of infection if present. Treatment with systemic agents may be required in severe cases, but must be supervised by an immunologist. Urticaria (hives) may affect up to a quarter of people at some time in their lives. Acute urticaria is more common in children, while chronic urticaria is more common in adults. Chronic urticaria is not life-threatening, but the associated pruritus and unsightly weals can cause patients much distress and significantly affect their daily lives. Angioedema coexists with urticaria in about 50% of patients. It typically affects the lips, eyelids, palms, soles and genitalia. Management of urticaria is through education; avoidance of triggers and allergens (where relevant); use of antihistamines to reduce itch; and short-term use of corticosteroids when antihistamine therapy is ineffective. Referral is indicated for patients with resistant disease.

Symptom prevalence and clustering of symptoms in people living with chronic hepatitis C infection

Quality of life has been shown to be poor among people living with chronic hepatitis C However, it is not clear how this relates to the presence of symptoms and their severity. The aim of this study was to describe the typology of a broad array of symptoms that were attributed to hepatitis C virus (HCV) infection. Phase I used qualitative methods to identify symptoms. In Phase 2, 188 treatment-naive people living with HCV participated in a quantitative survey. The most prevalent symptom was physical tiredness (86%) followed by irritability (75%), depression (70%), mental tiredness (70%), and abdominal pain (68%). Temporal clustering of symptoms was reported in 62% of participants. Principal components analysis identified four symptom clusters: neuropsychiatric (mental tiredness, poor concentration, forgetfulness, depression, irritability, physical tiredness, and sleep problems); gastrointestinal (day sweats, nausea, food intolerance, night sweats, abdominal pain, poor appetite, and diarrhea); algesic (joint pain, muscle pain, and general body pain); and dysesthetic (noise sensitivity, light sensitivity, skin. problems, and headaches). These data demonstrate that symptoms are prevalent in treatment-naive people with HCV and support the hypothesis that symptom clustering occurs.

Studies on enhanced surface disinfection and skin antisepsis using chlorhexidine and eucalyptus oil

Healthcare associated infections may arise from many sources, including patient?s own skin flora and the clinical environment, and inflict a significant burden within the health service. Adequate and effective skin antisepsis and surface disinfection are therefore essential factors in infection control. Current EPIC guidelines recommend 2 % chlorhexidine (CHG) in 70 % isopropyl alcohol (IPA) for skin antisepsis however poor penetration has been reported. Eucalyptus oil (EO) is a known permeation enhancer, producing synergistic antimicrobial activity when combined with CHG. In this current study, the antimicrobial efficacy of EO and its main constituent 1,8-cineole were assessed against a panel of clinically relevant microorganisms, alone and in combination with CHG. The superior antimicrobial efficacy of EO compared with 1,8-cineole, and synergistic effects with CHG against planktonic and biofilm cultures, confirmed its suitability for use in subsequent studies within this thesis. Impregnation of EO, CHG and IPA onto prototype hard surface disinfectant wipes demonstrated significantly improved efficacy compared with CHG/IPA wipes, with clear reductions in the time required to eliminate biofilms. Optimisation of the EO/CHG/IPA formulation resulted in the development of Euclean® wipes, with simulated-use and time kill studies confirming their ability to remove microbial surface contamination, prevent cross contamination and eliminate biofilms within 10 minutes. The employment of isothermal calorimetry provided additional information on the type and rate of antimicrobial activity possessed by Euclean® wipes. A clinical audit of the Euclean® wipes at Birmingham Children?s Hospital, Birmingham, U.K. revealed divided staff opinion, with the highest cited advantage and disadvantage concerning the odour. Finally, skin penetration and cell toxicity studies of EO/CHG biopatches and Euclean® solution developed during this study, revealed no permeation into human skin following biopatch application, and no significant toxicity. These current studies enhance the knowledge regarding EO and its potential applications.

Evaluation of a 2% chlorhexidine gluconate in 70% isopropyl alcohol skin disinfectant

The efficacy of a new skin disinfectant, 2% (w/v) chlorhexidine gluconate (CHG) in 70% (v/v) isopropyl alcohol (IPA) (ChloraPrep®), was compared with five commonly used skin disinfectants against Staphylococcus epidermidis RP62A in the presence or absence of protein, utilizing quantitative time-kill suspension and carrier tests. All six disinfectants [70% (v/v) IPA, 0.5% (w/v) aqueous CHG, 2% (w/v) aqueous CHG, 0.5% (w/v) CHG in 70% (v/v) IPA and 10% (w/v) aqueous povidone iodine (PI)] achieved a log10 reduction factor of 5, in colony-forming units/mL, in a suspension test (exposure time 30 s) in the presence and absence of 10% human serum. Subsequent challenges of S. epidermidis RP62A in a biofilm (with and without human serum) demonstrated reduced bactericidal activity. Overall, the most effective skin disinfectants tested against S. epidermidis RP62A were 2% (w/v) CHG in 70% IPA and 10% (w/v) PI. These results suggest that enhanced skin antisepsis may be achieved with 2% (w/v) CHG in 70% (v/v) IPA compared with the three commonly used CHG preparations [0.5% (w/v) aqueous CHG, 2% (w/v) aqueous CHG and 0.5% (w/v) CHG in 70% (v/v) IPA]. © 2005 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved.

The source, cost and prevention of central venous catheter-related infection

Central venous catheters have become an integral part of patient management however they are associated with many complications including infection. Despite efforts being made to reduce the incidence of such infect ions the problem continues to increase and has resource implications for the Health Service. Studies relating to the source of microorganisms causing CVC-associated infection, the cost of such infections and the efficacy of an antimicrobial catheter have been undertaken. Thirty patients who required a CVC as part of their medical management and underwent cardiac surgery had the distal tips of their catheters sampled whilst in situ. Sampling took place within 1 h of catheter placement. Bacteria were isolated from 16% of the catheter distal tips sampled in situ. The guidewires used to insert the devices were also contaminated (50%). When CVC were inserted via a protective sheath, avoiding contact with the skin. the incidence of microbial contamination was reduced. These findings suggest that despite rigorous skin disinfection and strict aseptic technique, viable microorganisms are impacted onto the distal tip of CVC during the insertion procedure. Needleless intravascular access devices have been introduced in order to reduce the incidence of need1estick injury. However, it was unclear whether such connectors would act as a portal of entry for microorganisms to CVC. The efficacy of these devices was investigated. Within the controlled laboratory environment it was demonstrated that needleless devices, when challenged with microorganisms, did not allow the passage of microbes when flu id was injected. This therefore suggested that the devices should not increase the risk of catheter colonisation. When used in clinical practice however microbial contamination of the needleless connectors was 55 % in comparison to the routinely used luer connectors (23%). The cost of infections associated with CVC was determined. Twenty patients catheterised with a CVC designed for long term use who were admitted to hospital with a presumptive diagnosis of catheter-related infection were studied. The treatment given specifically for this infection was costed. The mean cost of such an infection was £ 1781.81. Throughout the UK this may amount to £1.565.906 per annum. The cost of infections associated with CVC designed for short term use was estimated to be between 5 and 7 million pounds per annum in the UK. In an attempt to reduce both the incidence and cost of catheter- related infection antimicrobial CVC have been developed. The efficacy of a novel polyurethane CVC impregnated on both the internal and external catheter surface with the quaternary ammonium compound benzalkonium chloride was investigated. Eighty eight patients received an antimicrobial catheter and 78 patients a conventional polyurethane CVC. The anti-microbial CVC resulted in a reduction in microbial colonisation of the external and internal polymer surfaces as compared to the control device. The observed reduction in microbial colonisation with the anti-microbial CVC may decrease the likelihood of subsequent infection offering a useful approach to the prevention of catheter-related infections.

The prevention and diagnosis of central venous catheter-related infection

The potential source of CVC colonisation was assessed. Isolates of coagulase-negative staphylococci (CoNS) recovered from the skin and CVC components of 3 cardiothoracic surgery patients were characterised by pulsed-field gel electrophoresis (PFGE). The genetic heterogeneity of CoNS isolated from the skin was demonstrated and specific genotypes implicated in catheter colonisation. In addition, phenotypic and genotypic typing techniques were assessed for their ability to characterise strains of CoNS recovered from 33 patients who developed catheter-related bloodstream infection (CR-BSI) on a bone marrow transplant (BMT) unit and Siaphylococcus aureus recovered from 6 cardiothoracic surgery patients with surgical site infection (SSI) following median sternotomy. This epidemiological investigation revealed that common strains of CoNS and 51 aureus where not associated with infection in patients with CR-BSI or sternal SSI during the study period. Furthermore, there was no correlation between phenotypic and genotypic characterisation results. The variable expression of phenotypic traits within strains of staphylococci was evident whilst PFGE and randomly amplified polymorphic DNA (RAPD) were highly discriminatory for the molecular characterisation of S. aureus and CoNS. This was highlighted in 8 stem cell transplant (SCT) patients whereby it was demonstrated that routine identification and characterisation of CoNS by phenotypic techniques may not be adequate for the diagnosis of CR-BSI by current guidelines. The potential of the lipid S ELISA to facilitate the diagnosis of CR-BSI in 38 haematology/SCT patients and sternal SSI in 57 cardiothoracic surgery patients was also assessed. The ELISA proved to be a sensitive test for the rapid serodiagnosis of infection due to staphylococci in immunocompetent patients. The acridine orange leucocyte cytospin test (AOLC) was also evaluated for the rapid diagnosis of CR-BSI in 16 haematology/SCT patients with Hickman CVC in situ. Although the sensitivity of the test was low, it may provide a useful adjunct to conventional methods for the in situ sampling of catheters to predict and diagnose CR-BSI, preventing the unnecessary removal of CVC.

Efficacy of Adding 2% (w/v) Chlorhexidine Gluconate to 70% (v/v) Isopropyl Alcohol for Skin Disinfection Prior to Peripheral Venous Cannulation

We undertook a clinical trial to compare the efficacy of 2% (w/v) chlorhexidine gluconate in 70% (v/v) isopropyl alcohol with the efficacy of 70% (v/v) isopropyl alcohol alone for skin disinfection to prevent peripheral venous catheter colonization and contamination. We found that the addition of 2% chlorhexidine gluconate reduced the number of peripheral venous catheters that were colonized or contaminated. © 2008 by The Society for Healthcare Epidemiology of America. All rights reserved.

A randomized, prospective clinical trial to assess the potential infection risk associated with the PosiFlow® needleless connector

The microbial contamination rate of luers of central venous catheters (CVCs) with either PosiFlow® needleless connectors or standard caps attached was investigated. The efficacy of 70% (v/v) isopropyl alcohol, 0.5% (w/v) chlorhexidine in gluconate 70% (v/v) isopropyl alcohol and 10% (w/v) aqueous povidone-iodine to disinfect the intravenous connections was also assessed. Seventy-seven patients undergoing cardiac surgery who required a CVC as part of their clinical management were randomly allocated either needleless connectors or standard caps. Patients were also designated to receive chlorhexidine/alcohol, isopropyl alcohol or povidone-iodine for pre-CVC insertion skin preparation and disinfection of the connections. After 72 h in situ the microbial contamination rate of 580 luers, 306 with standard caps and 274 with needleless connectors attached, was determined. The microbial contamination rate of the external compression seals of 274 needleless connectors was also assessed to compare the efficacy of the three disinfectants. The internal surfaces of 55 out of 306 (18%) luers with standard caps were contaminated with micro-organisms, whilst only 18 out of 274 (6.6%) luers with needleless connectors were contaminated (P<0.0001). Of those needleless connectors disinfected with isopropyl alcohol, 69.2% were externally contaminated with micro-organisms compared with 30.8% disinfected with chlorhexidine/alcohol (P<0.0001) and 41.6% with povidone-iodine (P<0.0001). These results suggest that the use of needleless connectors may reduce the microbial contamination rate of CVC luers compared with the standard cap. Furthermore, disinfection of needleless connectors with either chlorhexidine/alcohol or povidone-iodine significantly reduced external microbial contamination. Both these strategies may reduce the risk of catheter-related infections acquired via the intraluminal route. © 2003 The Hospital Infection Society. Published by Elsevier Science Ltd. All rights reserved.

Chlorhexidine and the prevention of surgical site infection

Surgical site infections (SSI) are a prevalent health care-associated infection (HAl). Prior to the mid-19th century, surgical sites commonly developed postoperative wound complications. It was in the 1860's, after Joseph Lister introduced carbolic acid and the principles of antisepsis that postoperative wound infection significantly decreased. Today, patient preoperative skin preparation with an antiseptic agent prior to surgery is a standard of practice. Povidone-iodine and chlorhexidine gluconate are currently the most commonly used antimicrobial agents used to prep the patient's skin. In this current study, the epidemiology, diagnosis, surveillance and prevention of SSI with chlorhexidine were investigated. The antimicrobial activity of chlorhexidine was assessed. In in-vitro and in-vivo studies the antimicrobial efficacy of 2% (w/v) chlorhexidine gluconate (CHG) in 70% isopropyl alcohol (IPA) and 10% povidoneiodine (PVP-I) in the presence of 0.9% normal saline or blood were examined. The 2% CHG in 70% IPA solutions antimicrobial activity was not diminished in the presence of 0.9% normal saline or blood. In comparison, the traditional patient preoperative skin preparation, 10% PVP-I antimicrobial activity was not diminished in the presence of 0.9% normal saline, but was diminished in the presence of blood. In an in-vivo human volunteer study the potential for reduction of the antimicrobial efficacy of aqueous patient preoperative skin preparations compromised by mechanical removal of wet product from the application site (blot) was assessed. In this evaluation, 2% CHG and 10% povidone-iodine (PVP-I) were blotted from the patient's skin after application to the test site. The blotting, or mechanical removal, of the wet antiseptic from the application site did not produce a significant difference in product efficacy. In a clinical trial to compare 2% CHG in 70% IPA and PVP-! scrub and paint patient preoperative skin preparation for the prevention of SSI, there were 849 patients randomly assigned to the study groups (409 in the chlorhexidine-alcohol and 440 in the povidone-iodine group) in the intention-to-treat analysis. The overall surgical site infection was significantly lower in the 2% CHG in 70% IPA group than in the PVP-I group (9.5% versus 16.1 %, p=0.004; relative risk, 0.59 with 95% confidence interval of 0.41 to 0.85). Preoperative cleansing of the patient's skin with chlorhexidine-alcohol is superior to povidone-iodine in preventing surgical site infection after clean-contaminated surgery.

Simvastatin improves the healing of infected skin wounds of rats

This study explores the potential of the simvastatin to ameliorate inflammation and infection in open infected skin wounds of rats. Methods: Fourteen Wistar rats weighing 285±12g were used. The study was done in a group whose open infected skin wounds were treated with topical application of sinvastatina microemulsion (SIM, n=7) and a second group with wounds treated with saline 0.9 % (SAL, n=7). A bacteriological exam of the wounds fluid for gram positive and gram negative bacteria, the tecidual expression of TNFá and IL-1â by imunohistochemical technique, and histological analysis by HE stain were performed. Results: The expression of TNFa could be clearly demonstrated in lower degree in skin wounds treated with simvastatin (668.6 ± 74.7 ìm2) than in saline (2120.0 ± 327.1 ìm2). In comparison, wound tissue from SIM group displayed leukocyte infiltration significantly lower than that observed in SAL group (p<0.05). Culture results of the samples taken from wound fluid on fourth post treatment day revealed wound infection in only one rat of group simvastatin (SIM), where Proteus mirabilis, Escherchia coli and Enterobacter sp were isolated. In the rats whose wounds were treated with saline (SAL), polymicrobial infection with more than 100,000 CFU/g was detected in all the wounds. Conclusion: In addition to its antiinflammatory properties, the protective effects of simvastatin in infected open skin wounds is able to reduce infection and probably has antibacterial action. The potential to treat these wounds with statins to ameliorate inflammation and infection is promising

Simvastatin improves the healing of infected skin wounds of rats

This study explores the potential of the simvastatin to ameliorate inflammation and infection in open infected skin wounds of rats. Methods: Fourteen Wistar rats weighing 285±12g were used. The study was done in a group whose open infected skin wounds were treated with topical application of sinvastatina microemulsion (SIM, n=7) and a second group with wounds treated with saline 0.9 % (SAL, n=7). A bacteriological exam of the wounds fluid for gram positive and gram negative bacteria, the tecidual expression of TNFá and IL-1â by imunohistochemical technique, and histological analysis by HE stain were performed. Results: The expression of TNFa could be clearly demonstrated in lower degree in skin wounds treated with simvastatin (668.6 ± 74.7 ìm2) than in saline (2120.0 ± 327.1 ìm2). In comparison, wound tissue from SIM group displayed leukocyte infiltration significantly lower than that observed in SAL group (p<0.05). Culture results of the samples taken from wound fluid on fourth post treatment day revealed wound infection in only one rat of group simvastatin (SIM), where Proteus mirabilis, Escherchia coli and Enterobacter sp were isolated. In the rats whose wounds were treated with saline (SAL), polymicrobial infection with more than 100,000 CFU/g was detected in all the wounds. Conclusion: In addition to its antiinflammatory properties, the protective effects of simvastatin in infected open skin wounds is able to reduce infection and probably has antibacterial action. The potential to treat these wounds with statins to ameliorate inflammation and infection is promising

Survey of parasitic infection of Sander lucioperca (Linnaeus, 1758) and Silurus glanis (Linnaeus, 1758) in Aras reservoir with emphasizes of monogenean parasites

The parasites fauna of 491 specimens of Sander lucioperca, Linnaeus 1758 (246 specimens) and catfish, Silurus glanis, Linnaeus 1758 (245 specimens) in different size from Aras Reservoir situated in North —west of the Iran was investigated. During 2006-2007 Totally 16 parasite species were recorded. The most various parasites was found in catfish (10 species) while the lowest number was recorded in Sander lucioperca (6 species). Among them, however three genera of protozoa (Trichodina, Vorticella, Ichthyophthirius), two genera of Monogenea (Gyrodactylus, Silurodiscoides), Digenea, Cestoda, Nematoda, Acanthocephala and Annelida one species each (Diplostomum, Protocephalus, Eustrongylides, Neoechinorhynchus, Pisicola) and two crustacean genera (Argulus and Lernea) recorded and we can come to conclusion in comparison with the earlier data the actual parasite fauna of two hosts has been greatly improved. According to the present study the prevalence, mean abundance and mean intensity of parasites species of both hosts were highly influenced by seasons of the year. Some species found, however show a tendency to be more abundant ides Trichodina sp., Ichthyophthirius multifiliis, Silurodiscoides vistolensis, Protocephalus osculatus respectively. Most parasites species live in gills and skin, where is highly sensitive to some pathogens parasites species (Trichodina, Vorticella, Ichthyophthirius, Pisicola geometra, Argulus foliaceus; Lernea) and While some are specialist (Silurodiscoides vistolensis and Silurodiscoides siluri) other more or less generalist (ichthyophthirius).

The microbiological signature of human cutaneous leishmaniasis lesions exhibits restricted bacterial diversity compared to healthy skin

Localised cutaneous leishmaniasis (LCL) is the most common form of cutaneous leishmaniasis characterised by single or multiple painless chronic ulcers, which commonly presents with secondary bacterial infection. Previous culture- based studies have found staphylococci, streptococci, and opportunistic pathogenic bacteria in LCL lesions, but there have been no comparisons to normal skin. In addition, this approach has strong bias for determining bacterial composition. The present study tested the hypothesis that bacterial communities in LCL lesions differ from those found on healthy skin (HS). Using a high throughput amplicon sequencing approach, which allows for better populational evaluation due to greater depth coverage and the Quantitative Insights Into Microbial Ecology pipeline, we compared the microbiological signature of LCL lesions with that of contralateral HS from the same individuals. Streptococcus , Staphylococcus , Fusobacterium and other strict or facultative anaerobic bacteria composed the LCL microbiome. Aerobic and facultative anaerobic bacteria found in HS, including environmental bacteria, were significantly decreased in LCL lesions (p < 0.01). This paper presents the first comprehensive microbiome identification from LCL lesions with next generation sequence methodology and shows a marked reduction of bacterial diversity in the lesions.

Hypertrophic Adenoid Is A Major Infection Site Of Human Bocavirus 1.

Human bocavirus 1 (HBoV1) is associated with respiratory infections worldwide, mainly in children. Similar to other parvoviruses, it is believed that HBoV1 can persist for long periods of time in humans, probably through maintaining concatemers of the virus single-stranded DNA genome in the nuclei of infected cells. Recently, HBoV-1 was detected in high rates in adenoid and palatine tonsils samples from patients with chronic adenotonsillar diseases, but nothing is known about the virus replication levels in those tissues. A 3-year prospective hospital-based study was conducted to detect and quantify HBoV1 DNA and mRNAs in samples of the adenoids (AD), palatine tonsils (PT), nasopharyngeal secretions (NPS), and peripheral blood (PB) from patients undergoing tonsillectomy for tonsillar hypertrophy or recurrent tonsillitis. HBoV1 was detected in 25.3% of the AD samples, while the rates of detection in the PT, NPS, and PB samples were 7.2%, 10.5%, and 1.7%, respectively. The viral loads were higher in AD samples, and 27.3% of the patients with HBoV had mRNA detectable in this tissue. High viral loads and detectable mRNA in the AD were associated with HBoV1 detection in the other sample sites. The adenoids are an important site of HBoV1 replication and persistence in children with tonsillar hypertrophy. The adenoids contain high HBoV1 loads and are frequently positive for HBoV mRNA, and this is associated with the detection of HBoV1 in secretions.