Peter S. Friedmann

Prevalence of solar damage and actinic keratosis in a Merseyside population

This study examines the prevalence of sun‐related damage to the skin in a caucasian population in north‐west England. The importance of constitutional factors (complexion, skin type and age) as well as environmental and occupational exposures for the development of actinic keratosis (AK) and skin cancers was assessed in people over 40 years of age attending outpatient clinics (non‐dermatology) at four centres in north‐west England (Mersey region). Nine hundred and sixty‐eight volunteers (531 men and 437 women) were recruited. The overall prevalence of AK was 15·4% in men and 5·9% in women. The prevalence was strongly related to age in both sexes, being 34·1% and 18·2%, respectively, in men and women aged 70 years and above, and was most strongly related to two objective signs of sun exposure, namely degree of solar elastosis and presence of solar lentigines. The prevalence of AK was higher in subjects with red hair and freckles, particularly women. There was no evidence of an increased prevalence of AK in relation to any occupation. There was a high prevalence of seborrhoeic keratosis and viral warts in both sexes, which was age‐related in the case of seborrhoeic keratosis. Ten cases of basal cell carcinoma, eight cases of Bowen’s disease and one case of malignant melanoma were identified. This study shows that the sun exposure received in ‘normal’ life in England is sufficient to cause potentially malignant skin damage in a significant proportion of the population.

MicroRNA-155 modulates the pathogen binding ability of dendritic cells (DCs) by down-regulation of DC-specific intercellular adhesion molecule-3 grabbing non-integrin (DC-SIGN).

MicroRNA-155 (miR-155) has been involved in the response to inflammation in macrophages and lymphocytes. Here we show how miR-155 participates in the maturation of human dendritic cells (DC) and modulates pathogen binding by down-regulating DC-specific intercellular adhesion molecule-3 grabbing non-integrin (DC-SIGN), after directly targeting the transcription factor PU.1. During the maturation of DCs, miR-155 increases up to 130-fold, whereas PU.1 protein levels decrease accordingly. We establish that human PU.1 is a direct target for miR-155 and localize the target sequence for miR-155 in the 3′-untranslated region of PU.1. Also, overexpression of miR-155 in the THP1 monocytic cell line decreases PU.1 protein levels and DC-SIGN at both the mRNA and protein levels. We prove a link between the down-regulation of PU.1 and reduced transcriptional activity of the DC-SIGN promoter, which is likely to be the basis for its reduced mRNA expression, after miR-155 overexpression. Finally, we show that, by reducing DC-SIGN in the cellular membrane, miR-155 is involved in regulating pathogen binding as dendritic cells exhibited the lower binding capacity for fungi and HIV protein gp-120 when the levels of miR-155 were higher. Thus, our results suggest a mechanism by which miR-155 regulates proteins involved in the cellular immune response against pathogens that could have clinical implications in the way pathogens enter the human organism.

Cyclosporine in severe childhood atopic dermatitis: A multicenter study

BACKGROUND Severe atopic dermatitis (AD) remains difficult to treat. Cyclosporine is effective in adults but has not previously been investigated in children with AD. OBJECTIVE The aims were to investigate the efficacy, safety, and tolerability of cyclosporine in severe refractory childhood AD. METHODS Subjects 2 to 16 years of age were treated for 6 weeks with cyclosporine, 5 mg/kg per day, in an open study. Disease activity was monitored every 2 weeks by means of sign scores, visual analogue scales for symptoms, and quality-of-life questionnaires. Adverse events were monitored. Efficacy and tolerability were assessed with five-point scales. RESULTS Twenty-seven children were treated. Significant improvements were seen in all measures of disease activity. Twenty-two showed marked improvement or total clearing. Quality of life improved for both the children and their families. Tolerability was considered good or very good in 25 subjects. CONCLUSION Cyclosporine may offer an effective, safe, and well-tolerated short-term treatment option for children with severe AD.

Long-term efficacy and safety of cyclosporin in severe adult atopic dermatitis.

A prospective, open, multicentre study was performed to investigate the efficacy and safety of longterm treatment with cyclosporin in adults with severe atopic dermatitis. Subjects were treated for a maximum of 48 weeks. For the first 8 weeks, cyclosporin was administered at 2.5 mg/kg per day. The dose was then adjusted according to response. Disease activity was monitored using the six‐area. six‐sign score and the proportion of skin involved. Pruritus and sleep disturbance were assessed using four‐point scales. Response was further evaluated on a five‐point scale. Adverse events. blood pressure and serum biochemistry were monitored. Tolerability was assessed on a five‐point scale.

BSACI guidelines for the management of drug allergy

These guidelines have been prepared by the Standards of Care Committee (SOCC) of the British Society for Allergy and Clinical Immunology (BSACI) and are intended for allergists and others with a special interest in allergy. As routine or validated tests are not available for the majority of drugs, considerable experience is required for the investigation of allergic drug reactions and to undertake specific drug challenge. A missed or incorrect diagnosis of drug allergy can have serious consequences. Therefore, investigation and management of drug allergy is best carried out in specialist centres with large patient numbers and adequate competence and resources to manage complex cases. The recommendations are evidence‐based but where evidence was lacking consensus was reached by the panel of specialists on the committee. The document encompasses epidemiology, risk factors, clinical patterns of drug allergy, diagnosis and treatment procedures. In order to achieve a correct diagnosis we have placed particular emphasis on obtaining an accurate clinical history and on the physical examination, as these are critical to the choice of skin tests and subsequent drug provocation. After the diagnosis of drug allergy has been established, communication of results and patient education are vital components of overall patient management.

Effect of house dust mite avoidance measures in children with atopic dermatitis.

Background House dust mite allergens are associated with atopic dermatitis (AD).  Objectives The aim of our study was to verify if house dust mite allergen avoidance measures can improve the clinical manifestations of AD in children.  Methods Forty‐one children (mean age 3·9 years) affected by AD associated with high total and/or specific IgE serum levels (‘extrinsic’ AD) were recruited. Clinical evaluation was performed utilizing the Severity Scoring of AD (SCORAD) index; dust was sampled from the children’s beds and tested using an enzyme‐linked immunosorbent assay. The study was planned in two parts. In the first part, a placebo‐controlled trial of 2 months duration, mite allergen avoidance measures (encasing mattresses and pillows; a weekly hot wash of bedding; frequent vacuum cleaning of living room and bedroom; soft toys and carpets regularly cleaned or removed; no pets allowed) were recommended to group A patients, but not to group B. In the second part of the study, environmental avoidance measures were recommended to initial control group B patients also. One year after the start of the study the amounts of mite allergen in the home and clinical score of AD were measured in both groups.  Results At the end of the first part of the study, significant decreases in major allergens of Dermatophagoides pteronyssinus (Der p1) and D. farinae (Der f1) load (from 393 to 94 ng m−2) and concentration (from 1·84 to 0·73 µg g−1 of dust) in children’s beds were observed in treatment group A. At the same time, in this group the mean SCORAD index improved significantly (from 33 to 26; P = 0·022). After 12 months, when all patients had used allergen avoidance measures, Der p1 + Der f1 load, concentration and clinical score had improved, reaching similar values in both groups.  Conclusions Simple mite allergen avoidance measures should be recommended to families with children affected by extrinsic AD in order to control the clinical manifestations and prevent mite sensitization.

The relationships between exposure dose and response in induction and elicitation of contact hypersensitivity in humans

Like all physiological systems, the human immune system exhibits dose–response relationships in its reactions. The strength of sensitization is related to the potency of the immunogen and the dose that reaches the immune system. In skin, as sensitizing dose per unit area (μg cm−2) is increased on a log scale, there is a sigmoid dose–response curve for subsequent reactivity. Similarly, the response to elicitation shows a classical sigmoid response to increasing challenge dose, with the dose per unit area again being the determinant. There is a clear inverse correlation between the strength of sensitization and the subsequent dose of antigen to which an individual will respond. This is reflected in the different challenge systems used to diagnose the existence of allergic contact sensitization to a given allergen. The occluded patch test aims to use the highest concentration possible to detect the weakest degrees of allergy, whereas the repeated open application test uses much lower concentrations similar to those encountered in real life, applied repeatedly but without occlusion, to assess clinical relevance. Many authors have attempted to use the lowest concentrations to which rare, highly sensitized individuals can react to define the concentrations which might be free of risk in terms of inducing allergic sensitization. However, it is clear that the dose–response relationships for induction of sensitivity by repeated low‐dose exposures must be carefully defined in future studies. This article reviews the dose–response relationships of human contact sensitization.

Chemokine Receptor 4 Plays a Key Role in T Cell Recruitment into the Airways of Asthmatic Patients

T lymphocytes of the Th2 type are central orchestrators of airway inflammation in asthma. The mechanisms that regulate their accumulation in the asthmatic airways remains poorly understood. We tested the hypothesis that CCR4, preferentially expressed on T lymphocytes of the Th2 type, plays a critical role in this process. We enumerated by flow cytometry the CCR4-expressing T cells from blood, induced sputum, and biopsy samples of patients with asthma and control subjects. We showed a positive correlation between the numbers of peripheral blood CCR4+ T cells and asthma severity, provided evidence of preferential accumulation of CCR4+ T cells in asthmatic airways, and demonstrated that CCR4+ but not CCR4− cells from patients with asthma produce Th2 cytokines. Explanted airway mucosal biopsy specimens, acquired by bronchoscopy from subjects with asthma, were challenged with allergen and the explant supernatants assayed for T cell chemotactic activity. Allergen-induced ex vivo production of the CCR4 ligand, CCL17 was raised in explants from patients with asthma when compared with healthy controls. Using chemotaxis assays, we showed that the T cell chemotactic activity generated by bronchial explants can be blocked with a selective CCR4 antagonist or by depleting CCR4+ cells from responder cells. These results provide evidence that CCR4 might play a role in allergen-driven Th2 cell accumulation in asthmatic airways. Targeting this chemokine receptor in patients with asthma might reduce Th2 cell-driven airway inflammation; therefore, CCR4 antagonists could be an effective new therapy for asthma. This study also provides wider proof of concept for using tissue explants to study immunomodulatory drugs for asthma.

Phenotype standardization for immune-mediated drug-induced skin injury

Advances in genetic research and molecular biology techniques have made it possible to begin to characterize the underlying genetic factors that predispose patients to serious forms of drug‐induced skin injury (DISI). To facilitate research in this area, we have set out standardized phenotypic definitions for (i) Stevens‐Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), (ii) acute generalized exanthematous pustulosis (AGEP), and (iii) hypersensitivity syndrome (HSS; also known as drug reaction with eosinophilia and systemic symptoms (DRESS) and drug‐induced hypersensitivity syndrome (DIHS)). A DISI Expert Working Group comprising participants with varied expertise reviewed and debated current terminology and diagnostic criteria for DISI and agreed on the minimum phenotypic criteria for selected forms of DISI (SJS/TEN, AGEP, and HSS). In addition, an algorithm has been developed to aid appropriate clinical categorization of patients with DISI. These standardized criteria will be important in facilitating adequate and accurate patient recruitment in order to advance research in pharmacogenomic, immunological, mechanistic, and epidemiological studies.

The role of stratum corneum and dermal microvascular perfusion in penetration and tissue levels of water-soluble drugs investigated by microdialysis

Background Hydrophilic drugs are poorly absorbed when applied topically, due to low partitioning through the lipid matrix of the stratum corneum. Cutaneous blood flow rapidly clears the absorbed drug, which may result in low tissue levels. This is of importance for topically applied drugs whose site of action is within the epidermis or dermis. Dermal drug levels can be measured using cutaneous microdialysis, which is a means of continuously sampling substances from the dermal extracellular fluid.