Pharmacology and toxicology of infant skin

Shedding light on key pharmacological knowledge and strategies for pediatric atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is an inflammatory disease affecting over 20% of the pediatric population, with 85% of cases presenting before the age of five. Recently, therapeutic options in pediatric patients have evolved rapidly, following extensive development in adult treatments.

AREAS COVERED

This review will encompass relevant molecular drivers, along with an overlook on treatment modalities in pediatric AD, as well as a summary of pipeline treatments in clinical trials for pediatric patients from PubMed, Google Scholar, and Clinicaltrials.gov up to July 2022. Topical corticosteroids are the mainstay for AD flares in adults and children. Topical approved agents in pediatric AD are calcineurin inhibitors, crisaborolecrisaborole, and ruxolitinib. Dupilumab is the only FDA approved biologic for patients with AD from six months of age. A Janus kinase inhibitor, upadacitinib, is a systemic treatment approved for pediatric AD patients (age >12 years). Systemic immunosuppressants used in pediatric AD include methotrexate, azathioprine, cyclosporinecyclosporine, and mycophenolate mofetil.

EXPERT OPINION

Data regarding disease prevention are conflicting, however, an abundance of research has transpired regarding amelioration of symptoms and induction of disease clearance by targeting numerous pathological mechanisms. Understanding the pediatric AD phenotype will further advance the field and the development of improved therapeutics.

Considerations for and against dosing rodent pups before 7 days of age in juvenile toxicology studies

This review focuses on preweaning ontogenic and developmental processes that can influence the selection of the appropriate age at which to start dosing rodent pups in juvenile animal studies (JAS). The ICH S11 guideline on 'Nonclinical Safety Testing in Support of Development of Paediatric Medicines' highlights the need to adapt the age from which animals are dosed according to the stage of development in the target organs/tissues of concern in the youngest pediatric patients. Rodents (rat or mouse) are the most common species for JAS. Despite previous practices, based on comparative ontogeny, it is rarely necessary to dose rodents younger than one week of age since postnatal day (PND)7 is appropriate to address concern for the vast majority of organs. In exceptional cases, earlier dosing (e.g., PND4) can be appropriate to address specific concern in preterm neonates and when a tissue of concern has a particularly early developmental trajectory in the rodent compared to humans. The comparative development of the CNS is particularly complex. While exposure of rodents from PND10 covers most CNS development stages relevant to human neonates, a later dosing start (yet, not later than PND14) can sometimes be appropriate to reflect specific aspects (e.g., transformation of GABAergic transmission). An extended study design including subsets of several ages can be helpful to address multiple concerns within a preweaning JAS. Such design can allow for individual assessment of each concern, whilst minimizing (potentially irrelevant) signals from tissues exposed at a developmental stage that do not match the human situation.

Skin Barrier Function in Infants: Update and Outlook

A good understanding of infant skin should provide a rationale for optimum management of the health of this integument. In this review, we discuss the skin barrier function of infants, particularly with reference to the use of diapers and baby wipes. The skin barrier of newborns continues to develop with age. Two years after birth, the barrier properties of infant skin closely resemble those of adult skin. However, several risk factors may contribute to impaired skin barrier and altered skin permeability in infants. Problems may arise from the use of diapers and baby wipes. The skin covered by a diaper is effectively an occluded environment, and thus is vulnerable to over-hydration. To date there has been no published information regarding dermal absorption of ingredients contained in baby wipes. Similarly, dermal absorption of topical ingredients in infants with underlying skin conditions has not been widely explored. Clearly, there are serious ethical concerns related to conducting skin permeation studies on infant skin. However, the increasing availability of non-invasive methods for in vivo studies is encouraging and offers new directions for studying this important patient group.

Development and Evaluation of an In Silico Dermal Absorption Model Relevant for Children

The higher skin surface area to body weight ratio in children and the prematurity of skin in neonates may lead to higher chemical exposure as compared to adults. The objectives of this study were: (i) to provide a comprehensive review of the age-dependent anatomical and physiological changes in pediatric skin, and (ii) to construct and evaluate an age-dependent pediatric dermal absorption model. A comprehensive review was conducted to gather data quantifying the differences in the anatomy and physiology of child and adult skin. Maturation functions were developed for model parameters that were found to be age-dependent. A pediatric dermal absorption model was constructed by updating a MoBi implementation of the Dancik et al. 2013 skin permeation model with these maturation functions. Using a workflow for adult-to-child model extrapolation, the predictive performance of the model was evaluated by comparing its predicted rates of flux of diamorphine, phenobarbital and buprenorphine against experimental observations using neonatal skin. For diamorphine and phenobarbital, the model provided reasonable predictions. The ratios of predicted:observed flux in neonates for diamorphine ranged from 0.55 to 1.40. For phenobarbital, the ratios ranged from 0.93 to 1.26. For buprenorphine, the model showed acceptable predictive performance. Overall, the physiologically based pediatric dermal absorption model demonstrated satisfactory prediction accuracy. The prediction of dermal absorption in neonates using a model-based approach will be useful for both drug development and human health risk assessment.

Sunscreens: UV filters to protect us: Part 1: Changing regulations and choices for optimal sun protection

Sunscreens are topical preparations containing any number of ultraviolet filters (UVFs). The first part of the review will focus on the recent Food and Drug Administration (FDA) regulations of 2019 and general use of these agents. While sunscreen products are becoming more regulated in the United States, we still lag behind other countries in our options for UVFs. Sun protection to prevent skin cancer and aging changes should be a combination of sun avoidance, protective structures, and clothing as well as use of sunscreen products. Newer and safer products are needed to help supplement and replace older agents as well as improve their cosmetic acceptability. This will be a review of ingredients, local toxicities (i.e. contact dermatitis, photocontact dermatitis), special considerations for children, and cosmesis of sunscreen preparations. Part 2 will focus on the environmental, ecological and human toxicities that have been increasingly related to UVFs.

The Most Useful Pharmaceutical Formulations (Individualized Medications) in Pediatric Dermatology: A Review

The administration of appropriate doses of active ingredients and excipients is crucial for achieving desired treatment outcomes in pediatric dermatology. A number of factors need to be considered, including the characteristics of the lesion, the patient, and the drug. An additional challenge in pediatric settings is the limited number of commercially available formulations suitable for use in children. Drug compounding, which is the preparation of medications tailored to the needs of individual patients, is a good alternative for pediatric populations for a number of reasons. Using a customized compound, the clinician can prescribe formulations that contain the optimal dose of the active ingredients within acceptable limits and the most suitable vehicle and formulation components. Compounding can also be used to combine several active ingredients in a single medication and even adapt the vehicle to the characteristics of the lesion and the needs of the patient. The pharmaceutical formulations described in this review are based on extensive clinical experience and can be customized to meet individual needs.

Functions of Small Organic Compounds that Mimic the HNK-1 Glycan

Because of the importance of the HNK-1 carbohydrate for preferential motor reinnervation after injury of the femoral nerve in mammals, we screened NIH Clinical Collection 1 and 2 Libraries and a Natural Product library comprising small organic compounds for identification of pharmacologically useful reagents. The reason for this attempt was to obviate the difficult chemical synthesis of the HNK-1 carbohydrate and its isolation from natural sources, with the hope to render such compounds clinically useful. We identified six compounds that enhanced neurite outgrowth from cultured spinal motor neurons at nM concentrations and increased their neurite diameter, but not their neurite branch points. Axons of dorsal root ganglion neurons did not respond to these compounds, a feature that is in agreement with their biological role after injury. We refer to the positive functions of some of these compounds in animal models of injury and delineate the intracellular signaling responses elicited by application of compounds to cultured murine central nervous system neurons. Altogether, these results point to the potential of the HNK-1 carbohydrate mimetics in clinically-oriented settings.

Development of a new diaper dermatitis-like reconstructed skin equivalent for testing children atopic dermatitis relieving cosmetics

BACKGROUND

Diaper dermatitis (DD) is the most common acute inflammatory skin disease. It has a serious effect on children's and families' quality of life. We aimed to screen and evaluate the efficacy of different formulas for relieving the diaper dermatitis symptoms by developing a kind of diaper dermatitis-like reconstructed human skin equivalent in vitro.

MATERIALS AND METHOD

We developed the human skin equivalent for diaper dermatitis with 0.2% Sodium lauryl sulfate (SLS). The diaper dermatitis-like human skin equivalent was characterized by high level of inflammation, such as overexpression of interleukin-1α (IL-1α), and impaired skin barrier. Four formulas with potential of anti-inflammation and promotion of skin barrier function were topically applied on the diaper dermatitis-like human skin equivalent surface. The afterward protection efficacy was evaluated by endpoints of IL-1α, tissue viability, and skin barrier function.

RESULTS

The chemical irritant induced high release of IL-1α, impaired tissue viability, and skin barrier function. The cream prepared with potential of anti-inflammation and skin protection could effectively decrease and relive the impact of irritant with decreased level of IL-1α and the higher tissue viability than the placebo exposure.

CONCLUSION

The results showed that diaper dermatitis-like human skin equivalent induced by SLS can mimic the skin irritation response of the diaper rash.

Skin Health Connected to the Use of Absorbent Hygiene Products: A Review

Over the past 50 years, absorbent hygiene products such as baby diapers and incontinence products have become essential features of modern day life. Through innovation and enhanced technology, their design, composition and performance have been dramatically upgraded from their early forms, and they have transformed the lives of millions of people, improving their quality of life. Skin health related to the use of absorbent hygiene products has accordingly also greatly improved. Still, the wearing of absorbent hygiene products will affect the skin, and for some users the changes in microclimate, mechanical interactions and the exposure to urine and faeces may result in irritant contact dermatitis, i.e. diaper dermatitis (DD) or incontinence-associated dermatitis (IAD). Babies with developing skin and the elderly with deteriorating skin functions who are the most frequent users of absorbent hygiene products are more vulnerable to the causal factors. Although irritant reactions are the most common, allergic contact dermatitis should be considered if a DD/IAD fails to improve by recommended actions. There is also a connection between IAD and pressure ulcer development of which it is important to be aware. A holistic approach of using high-quality absorbent hygiene products in combination with appropriate skin care will help maintaining good skin health.

Topical corticosteroid phobia in parents of pediatric patients with atopic dermatitis: a multicentre survey

Background

Families of children affected with atopic dermatitis (AD) often report fear and anxiety regarding treatment with topical corticosteroids (TCS), which may lead to reduced compliance. The objective of our study was to measure, through a standardized questionnaire, fear of TCS in families of pediatric patients with AD and to identify items associated with fear.

Methods

Families of pediatric patients with AD were enrolled in 9 Italian centers of pediatric dermatology. Enrolled parents were invited to fill in a questionnaire including questions on sociodemographic and clinical characteristics and 3 sets of questions on corticosteroid phobia (general fear, specific fears, behaviours regarding TCS). Determinants of the level of general fear were investigated through multivariable analysis.

Results

A total of 300 outpatients with AD were enrolled. Most parents (80%) had a high instruction level. Eighty-one percent reported to have a certain amount of fear of TCS. At the multivariable analysis, fear of TCS was associated with the following items: believing that TCS treatment advantages do not overweight disadvantages (P = 0.011); believing that TCS may be dangerous independently from the specific side effect (P < 0.001). Moreover, TCS fear was associated with fear of applying too much cream (P = 0.001).

Conclusion

TCS phobia is widespread among Italian families of children with AD. Fear of TCS is associated with fear of applying too much cream, thus increasing the risk of poor compliance and treatment failure. Therapeutic education of families on the use of TCS should be implemented.

Electronic supplementary material

The online version of this article (doi:10.1186/s13052-017-0330-7) contains supplementary material, which is available to authorized users.

Pediatric Cardiac Intensive Care Society 2014 Consensus Statement: Pharmacotherapies in Cardiac Critical Care: Sedation, Analgesia and Muscle Relaxant

OBJECTIVE

This article reviews pharmacotherapies currently available to manage sedation, analgesia, and neuromuscular blockade for pediatric cardiac critical patients.

DATA SOURCES

The knowledge base of an expert panel of pharmacists, cardiac anesthesiologists, and a cardiac critical care physician involved in the care of pediatric cardiac critical patients was combined with a comprehensive search of the medical literature to generate the data source.

STUDY SELECTION

The panel examined all studies relevant to management of sedation, analgesia, and neuromuscular blockade in pediatric cardiac critical patients.

DATA EXTRACTION

Each member of the panel was assigned a specific subset of the studies relevant to their particular area of expertise (pharmacokinetics, pharmacodynamics, and clinical care) to review and analyze.

DATA SYNTHESIS

The panel members each crafted a comprehensive summary of the literature relevant to their area of expertise. The panel, as a whole, then collaborated to cohesively summarize all the available, relevant literature.

CONCLUSIONS

In the cardiac ICU, management of the cardiac patient requires an individualized sedative and analgesic strategy that maintains hemodynamic stability. Multiple pharmacological therapies exist to achieve these goals and should be selected based on the patient's underlying physiology, hemodynamic vulnerabilities, desired level of sedation and analgesia, and the projected short- or long-term recovery trajectory.

Pharmacokinetics in neonatal prescribing: evidence base, paradigms and the future

Paediatric patients, particularly preterm neonates, present many pharmacological challenges. Due to the difficulty in conducting clinical trials in these populations dosing information is often extrapolated from adult populations. As the processes of absorption, distribution, metabolism and excretion of drugs change throughout growth and development extrapolation presents risk of over or underestimating the doses required. Information about the development these processes, particularly drug metabolism pathways, is still limited with weight based dose adjustment presenting the best method of estimating pharmacokinetic changes due to growth and development. New innovations in pharmacokinetic research, such as population pharmacokinetic modelling, present unique opportunities to conduct clinical trials in these populations improving the safety and effectiveness of the drugs used. More research is required into this area to ensure the best outcomes for our most vulnerable patients.

Current Management of Pediatric Vitiligo

Vitiligo is a common inflammatory disorder with worldwide prevalence of 0.4-2 % of the population, with half of cases beginning in childhood. The management of childhood vitiligo should be tailored to avoid negative effects on the overall growth and psychological development of the patient. Therapy of vitiligo in childhood is chosen based on the location of the lesions, lesion age, and extent of lesions in the context of the child's age and the developmental status of the child. There are four age categories in childhood vitiligo: [1] infantile and toddler (rare) (ages 0-3 years), [2] ages 4-8 years, [3] ages 9-12 years, and [4] 13+ years of age, based on developmental stage, psychological maturation, and ability to comply or participate in therapy. These categories are also differentiated psychologically by susceptibility to bullying, self-image development, and personal concern with lesion appearance, which increases with time. Intervention is advisable in cases with facial and leg involvement due to prominence of lesions and cosmetic defect. Medical interventions are largely the usage of topical therapies including corticosteroids and calcineurin inhibitors, some vitamin therapy (oral and topical vitamin D), and judicious introduction of phototherapy sources based on age and severity. Screening and appropriate subspecialist referral for co-morbidities (e.g., thyroid disease, celiac disease, psychological distress, and vitamin D deficiency) may enhance overall health. Cosmesis and camouflage are generally safe in childhood and have been noted to improve overall quality of life in this grouping. Genetic transmission of vitiligo is minimal at 5-6 % in first-degree relatives. This article reviews the therapeutics of pediatric vitiligo from the perspective of developmental stages and response to therapy.

Newborn infant skin: physiology, development, and care

Infant skin is critical to the newborn child's transition from the womb environment to the journey to self-sufficiency. This review provides an integrative perspective on the skin development in full term and premature infants. There is a particular focus on the role of vernix caseosa and on the implications of skin development for epidermal penetration of exogenous compounds. Healthy full-term newborn skin is well-developed and functional at birth, with a thick epidermis and well-formed stratum corneum (SC) layers. Transepidermal water loss is very low at birth, equal to, or lower than adults, indicating a highly effective skin barrier. Vernix facilitates SC development in full-term infants through a variety of mechanisms including physical protection from amniotic fluid and enzymes, antimicrobial effects, skin surface pH lowering, provision of lipids, and hydration. Premature infants, particularly those of very low birth weight, have a poor skin barrier with few cornified layers and deficient dermal proteins. They are at increased risk for skin damage, increased permeability to exogenous agents and infection. The SC barrier develops rapidly after birth but complete maturation requires weeks to months. The best methods for caring for infant skin, particularly in the diaper region, are described and related to these developmental changes.

Pharmacovigilance for children's sake

Child age-specific information on efficacy and risk of medicines can be limited for healthcare professionals and patients. It is therefore very important to make the best use of a risk planned approach to the pharmacological treatment of children. This means pharmacovigilance in the broadest sense of gaining the best data from the use of medicines in clinical practice. We consider issues that complicate safe medication use in paediatric care, as well as current progress and provide suggestions for building knowledge within paediatric pharmacovigilance to be used to minimise patient harm. The continuous development in children constitutes a challenge to prescribing and administering age-suitable doses for individual children. Children are not only different from adults but differ vastly within their own age group. Physical growth during childhood is apparent to the eye, but less obvious is the ongoing maturation of organ function important for drug disposition and action. Systematic issues such as medication errors, off-label use and the lack of age-suitable formulations are considerable obstacles for safe medication use in paediatrics. The recognition of emerging adverse drug reactions could be more challenging in developing children. Initiatives to improve the situation have been made by the WHO and regulators in the USA and EU. Age-specific changes in physiology, pharmacology and psychology, as well as systematic issues specific for children need to be considered in the work of assessing spontaneous reports in children. Pharmacovigilance needs to broaden its aims considerably beyond merely capturing new associations between drugs and events, and encompass careful collection on patient characteristics and circumstances around the reported adverse drug reaction to provide essential information that will give clues on how to prevent harm to children.

Neonatal skin care in tertiary Neonatal Intensive Care Units in Hungary

Introduction: Skin physiology of neonates and preterm infants and evidence-based skin care are not well explored for health care providers. Aim: The aim of our present study was to investigate the skin care methods of the tertiary Neonatal Intensive Care Units in Hungary. Method: A standardized questionnaire was distributed among the 22 tertiary Neonatal Intensive Care Units with questions regarding skin care methods, bathing, emollition, skin disinfection, umbilical cord care, treatment of diaper dermatitis, and use of adhesive tapes. Results: The skin care methods of the centres were similar in several aspects, but there were significant differences between the applied skin care and disinfectant products. Conclusions: The results of this survey facilitate the establishment of a standardized skin care protocol for tertiary Neonatal Intensive Care Units with the cooperation of dermatologists, neonatologists and pharmacists. Orv. Hetil., 2014, 155(28), 1102–1107.

Sedation and analgesia in critically ill children

The interplay of pain, discomfort, and fear can cause agitation in critically ill children. Therefore, sedation and analgesia are essential components in the intensive care unit setting and are best managed with a multidisciplinary team approach. No one standard approach exists to assess and manage pain and anxiety. Many tools are available for the assessment of pain and sedation, but each tool has its advantages and disadvantages. Clinicians should consider adopting a validated tool for routine continuous assessment. Multiple pharmacological therapies are available to manage pain, anxiety, fear, and agitation. Dosing of these agents can be influenced by age-related pharmacokinetic and pharmacodynamic changes. Agents should be selected on the basis of the child's disease state, desired level of sedation, and cardiac and respiratory status.

Compounded ointment results in severe toxicity in a pediatric patient

BACKGROUND

Dermal drug delivery is becoming more common, as evidenced by the increased numbers of compounding pharmacies preparing topical products for chronic pain management. Consumers may not appreciate the potency or dangers associated with some of the drugs in these preparations. Pediatric patients are especially at risk for significant toxicity with accidental exposures. We report a case of severe toxicity in an 18-month-old boy from exposure to his father's compounded pain ointment.

CASE

An 18-month-old previously healthy child had an ointment applied topically to a diaper rash by his mother, consisting of a single pump of a prescription ointment that her husband received from a compounding pharmacy for neck pain. Approximately 20 minutes later, when the child had been put down for a nap, he had gasping respiration but was otherwise unresponsive. Emergency medical services was called, and the child was unresponsive. In the ED, vital signs were pulse of 57 beats/min, blood pressure 74/35 mm Hg, respiratory rate 21 breaths/min, and O2 saturation 98% on a nonrebreather. Fingerstick glucose was 105 mg/dL. In the ED, physical examination was significant for unresponsiveness, pinpoint pupils, and hyporeflexia. The patient's mental status continued to deteriorate with depressed respirations, and he was intubated. Laboratory results were noncontributory. Electrocardiogram revealed only sinus bradycardia. The patient was transported to a pediatric intensive care unit. He did well over the next several hours with supportive care and had return to normal vital signs over the following 12 hours. He was extubated the following morning without problems. Blood taken at the time of ED presentation had a serum clonidine level of 9.2 ng/mL (reference range, 0.5-4.5 ng/mL) and a norketamine level of 41 ng/mL (reporting limit, >20 ng/mL).

CONCLUSIONS

Dermal absorption of drugs leading to significant toxicity in children is well known. Our patient had toxicity from a topical pain medication compounded with several potent drugs known to cause central nervous system depression. There has been an increase in the use of this drug delivery system for management of chronic painful conditions. The popularity and attractiveness of such preparations may be the perception that they are somehow safer and more natural than taking pills. This perception and the fact that these are not dispensed in child-proof containers and are often mailed to the patients without pharmacist counseling can lead to increased inadvertent exposures in the pediatric population.

Chronic pruritus associated with dermatologic disease in infancy and childhood: update from an interdisciplinary group of dermatologists and pediatricians

An effective treatment strategy for chronic pruritus in children with dermatologic disorders should consider the multidimensional aspects of pruritus, the unique challenges associated with treating pruritic skin disorders in the pediatric population, and evidence-based therapies with demonstrated antipruritic benefits and clinically relevant effects on patient/family quality of life (QoL). The Course of Advanced Learning for the Management of ITch (CALM-IT) Task Force is an interdisciplinary group of experts specializing in core aspects of pruritus treatment, integrating pediatrics, dermatology, psychotherapy, pruritus management, and sleep. CALM-IT recently convened to provide updated guidance on managing chronic pruritus associated with dermatologic diseases in pediatric patients, with a special focus on atopic dermatitis (AD) and chronic spontaneous urticaria (csU). This review highlights the updated concepts and best practices, which were built upon international PRACTALL consensus and modified for children and infants with AD and csU. CALM-IT supports the routine use of basic skin therapy and the escalation of topical medications, according to severity and focused on rapid itch control. Anti-inflammatory agents should be appropriate for infants and children (i.e., with an optimized therapeutic index) and have proven antipruritic properties, such as those demonstrated by methylprednisolone aceponate. New experimental findings do not support the use of non-sedating oral antihistamines as adjuvant antipruritic therapy for AD. In csU, oral H1 -antihistamine use is justified, consistent with the distinct pathophysiologic mechanisms of itch underlying AD and csU. All encompassing QoL assessments should consider the burden of both patient and caregiver and should address outstanding unmet clinical needs of pediatric patients. Future research areas include integrated QoL assessments and multidisciplinary treatment programs with pediatric-targeted pruritic therapies providing rapid itch control.

Pediatric pharmacokinetics: human development and drug disposition

Human development is described by the various anatomic and physiologic changes that occur as the single-celled zygote matures into an adult human being. Concomitant with bodily maturation are changes in the complex interactions between pharmacologic agents and the biologic matrix that is the human body. Profound changes in the manner by which drugs traverse the body during development can have significant implications in drug efficacy and toxicity. Although not a replacement for well-conducted, pediatric, pharmacokinetic studies, an understanding of developmental biology and the mechanisms for drug disposition invariably assists the pediatric clinician with the judicious use of medications in children.

A randomized comparative trial on the therapeutic efficacy of topical aloe vera and Calendula officinalis on diaper dermatitis in children

Introduction. Diaper dermatitis (DD) is a common inflammatory disorder among children and infants. The objective of the present randomized and double-blind trial was to compare the therapeutic efficacies of Aloe vera cream and Calendula officinalis ointment on the frequency and severity of DD in children. Methods. Sixty-six infants with DD (aged < 3 years) were randomized to receive either Aloe cream (n = 32) or Calendula ointment (n = 34). Infants were treated with these drugs 3 times a day for 10 days. The severity of dermatitis was graded at baseline as well as at the end of trial using a 5-point scale. The adverse effects of study medications were assessed during the trial. Results. Although improvement in the severity of DD was observed in both treatment groups (P < 0.001), patients receiving Calendula ointment had significantly fewer rash sites compared to Aloe group (P = 0.001). No adverse effect was reported from either of the medications. Discussion. The evidence from this study suggests that topical Aloe and in particular Calendula could serve as safe and effective treatment for the treatment of diaper dermatitis in infants.

Optimizing the treatment of atopic dermatitis in children: a review of the benefit/risk ratio of methylprednisolone aceponate

Atopic dermatitis (AD) is a chronic, recurring, pruritic, inflammatory skin condition which has its onset in early childhood in most cases. A stepped approach to therapy, starting with emollients and adding first mild and then more potent topical medications is recommended. For more than 50 years, topical corticosteroids (TCs) have been the gold standard in AD therapy. Increasingly potent TCs have tended to come with increasing risk of adverse events, however. Calculating the benefit/risk ratio [or therapeutic index (TIX)] for TCs when treating children and infants is more challenging in this population. Not only does their increased surface area to volume ratio as a result of their small size mean that they are likely to absorb a greater proportion of any active agent applied to their skin, but drug metabolism is slower than in adults and the systemic effects of corticosteroids are more pronounced (in particular reduction of serum cortisol levels through suppression of the hypothalamic-pituitary-adrenal axis). Unlike traditional TCs, topical calcineurin inhibitors are not associated with the systemic effects and have shown good efficacy in treating AD in children. Parental/Carer concerns about their long-term use can limit their acceptance for treatment in the paediatric population, however. Modifications to the structure of fourth generation corticosteroids mean that increased potency is not accompanied by increased risk of adverse events and hence they have an improved TIX. Methylprednisolone aceponate is a potent fourth generation corticosteroid which has demonstrated efficacy and safety in acute and maintenance programmes in infants and children. It is licenced for once-daily use, and is available in four formulations - ointment, fatty ointment, cream and milk, which combine with its improved TIX to meet the needs of young patients and their carers.

Ultraviolet radiation: a hazard to children and adolescents

Sunlight sustains life on earth. Sunlight is essential for vitamin D synthesis in the skin. The sun's ultraviolet rays can be hazardous, however, because excessive exposure causes skin cancer and other adverse health effects. Skin cancer is a major public health problem; more than 2 million new cases are diagnosed in the United States each year. Ultraviolet radiation (UVR) causes the 3 major forms of skin cancer: basal cell carcinoma; squamous cell carcinoma; and cutaneous malignant melanoma. Exposure to UVR from sunlight and artificial sources early in life elevates the risk of developing skin cancer. Approximately 25% of sun exposure occurs before 18 years of age. The risk of skin cancer is increased when people overexpose themselves to sun and intentionally expose themselves to artificial sources of UVR. Public awareness of the risk is not optimal, compliance with sun protection is inconsistent, and skin-cancer rates continue to rise in all age groups including the younger population. People continue to sunburn, and teenagers and adults are frequent visitors to tanning parlors. Sun exposure and vitamin D status are intertwined. Adequate vitamin D is needed for bone health in children and adults. In addition, there is accumulating information suggesting a beneficial influence of vitamin D on various health conditions. Cutaneous vitamin D production requires sunlight, and many factors complicate the efficiency of vitamin D production that results from sunlight exposure. Ensuring vitamin D adequacy while promoting sun-protection strategies, therefore, requires renewed attention to evaluating the adequacy of dietary and supplemental vitamin D. Daily intake of 400 IU of vitamin D will prevent vitamin D deficiency rickets in infants. The vitamin D supplementation amounts necessary to support optimal health in older children and adolescents are less clear. This report updates information on the relationship of sun exposure to skin cancer and other adverse health effects, the relationship of exposure to artificial sources of UVR and skin cancer, sun-protection methods, vitamin D, community skin-cancer-prevention efforts, and the pediatrician's role in preventing skin cancer. In addition to pediatricians' efforts, a sustained public health effort is needed to change attitudes and behaviors regarding UVR exposure.

Season of birth and risk for adult onset glioma

Adult onset glioma is a rare cancer which occurs more frequently in Caucasians than African Americans, and in men than women. The etiology of this disease is largely unknown. Exposure to ionizing radiation is the only well established environmental risk factor, and this factor explains only a small percentage of cases. Several recent studies have reported an association between season of birth and glioma risk. This paper reviews the plausibility of evidence focusing on the seasonal interrelation of farming, allergies, viruses, vitamin D, diet, birth weight, and handedness. To date, a convincing explanation for the occurrence of adult gliomas decades after a seasonal exposure at birth remains elusive.

Assessment of exposure to pyrethroids and pyrethrins in a rural population of the Montérégie area, Quebec, Canada

Pesticide use remains a preoccupation of the population and public health authorities given its possible impact on health. Pyrethroids can be listed among the widely used pesticides. The general population is potentially chronically exposed to pyrethroids mainly through food intake, but acute or sporadic exposures can also occur by other routes. Although pyrethroids are considered among the least toxic pesticides, their neurotoxic properties can affect humans, but current exposure levels in the population of Quebec are not known. The study thus aimed at assessing pyrethroid exposure in a rural, agricultural population during summer through measurements of urinary biomarkers. A total of 163 volunteers, 49 children and 114 adults, living in the Montérégie area of Quebec, participated in the study, which took place from June to August 2006, the period of intensive application of pesticides. Participants were asked to collect all their micturitions from 6 p.m. until the next morning, including first morning void, and to fill out a questionnaire to document factors that could potentially contribute to exposure. A gas-chromatography mass-spectrometry method was used to quantify six urinary metabolites resulting from pyrethroid biotransformation: cis- and trans-2,2-(dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (cDCCA and tDCCA), 3-phenoxybenzoic acid (PBA), chrysanthemum dicarboxylic acid (CDCA), cis-2,2-(dibromovinyl)-2,2-dimethylcyclopropane carboxylic acid (DBCA) and 4-fluoro-3-phenoxybenzoic acid (FPBA). Distributions of amounts of the six metabolites excreted per unit of body weight, during a standardized 12-hr period, followed the same decreasing pattern in adults and in children: tDCCA > PBA > cDCCA > CDCA > DBCA > FPBA. No statistically significant difference was observed between the two groups, but amounts of metabolites varied greatly among individuals, suggesting important interindividual variations in the absorbed doses of these compounds. No consistent associations were observed between the excretion of correlated metabolites and the various factors documented by questionnaire (personal factors, life habits, sources of exposure). Comparison of the current data with those observed in an urban population of the same province during the summer of 2005 suggests a greater summertime exposure to some pyrethroids in the rural population.

Dermal sensitization quantitative risk assessment (QRA) for fragrance ingredients

Based on chemical, cellular, and molecular understanding of dermal sensitization, an exposure-based quantitative risk assessment (QRA) can be conducted to determine safe use levels of fragrance ingredients in different consumer product types. The key steps are: (1) determination of benchmarks (no expected sensitization induction level (NESIL)); (2) application of sensitization assessment factors (SAF); and (3) consumer exposure (CEL) calculation through product use. Using these parameters, an acceptable exposure level (AEL) can be calculated and compared with the CEL. The ratio of AEL to CEL must be favorable to support safe use of the potential skin sensitizer. This ratio must be calculated for the fragrance ingredient in each product type. Based on the Research Institute for Fragrance Materials, Inc. (RIFM) Expert Panel's recommendation, RIFM and the International Fragrance Association (IFRA) have adopted the dermal sensitization QRA approach described in this review for fragrance ingredients identified as potential dermal sensitizers. This now forms the fragrance industry's core strategy for primary prevention of dermal sensitization to these materials in consumer products. This methodology is used to determine global fragrance industry product management practices (IFRA Standards) for fragrance ingredients that are potential dermal sensitizers. This paper describes the principles of the recommended approach, provides detailed review of all the information used in the dermal sensitization QRA approach for fragrance ingredients and presents key conclusions for its use now and refinement in the future.

Hamamelis in children with skin disorders and skin injuries: results of an observational study

Published clinical experience with hamamelis ointment in children is limited. This observational study included children (age 27 days to 11 years) with minor skin injuries, diaper dermatitis, or localized inflammation of skin. The children received either hamamelis ointment or dexpanthenol ointment in groups at a 3-to-1 ratio. Baseline and post-treatment assessments compared the total scores of predefined signs and symptoms for each condition. Physicians and parents were asked for a global assessment of efficacy and tolerability of the respective treatments at the end of therapy. A total of 309 children were treated (hamamelis n = 231; dexpanthenol n = 78). The treatment groups were comparable regarding demographic data and baseline total scores of signs and symptoms. In all three diagnosis groups, the efficacy of hamamelis and dexpanthenol was shown by a statistically significant and clinically relevant decrease of total scores from baseline to endpoint (p < 0.0001 for each group, Wilcoxon signed-rank test). Overall, the results for the hamamelis and the dexpanthenol groups were similar. Descriptive advantages for the hamamelis group were observed for a number of parameters and diagnosis groups. Both treatments were well tolerated. Ratings of the tolerability of hamamelis were "excellent" or "good" in 99.1% (physicians) and 98.2% (parents) of cases, respectively. The corresponding ratings for dexpanthenol were 97.4 and 92.3%. In conclusion, hamamelis ointment is an effective and safe treatment for certain skin disorders in children up to the age of 11 years. The observed effects are similar to dexpanthenol.

What do we (need to) know about the kinetic properties of nanoparticles in the body?

Nowadays the development and applications of nanotechnology are of major importance in both industrial and consumer areas. However, the knowledge on human exposure and possible toxicity of nanotechnology products is limited. To understand the mechanism of toxicity, thorough knowledge of the toxicokinetic properties of nanoparticles is warranted. There is a need for information on the absorption, distribution, metabolism and excretion (ADME) of nanoparticles and validated detection methods of these man-made nanoparticles. Determination of the ADME properties of nanoparticles requires specialised detection methods in different biological matrices (e.g. blood and organs). In this paper, the current knowledge on the kinetic properties of nanoparticles is reviewed. Moreover, knowledge gaps from a kinetic point of view (detection, dose, ADME processes) are identified.

Approach to procedures in neonates

Physical constraints and metabolic differences in neonates require that special attention is given to performing procedures in this patient group. Neonates have a thinner dermis and a greater surface-to-weight ratio, allowing for easier invasion through the skin barrier. The enzymes for metabolism of agents and defense against organisms inside the body are not fully developed in infants. Very premature neonates also have less circulating albumin, making the effective concentration of circulating agent even greater. The infant is prone to unanticipated movement during procedures, such as rolling on the procedure table. The neonatal period is the most common time period for malformations to become manifest on the skin, and invasion of some of these lesions can produce morbidity. These and other factors affect the choice of the type of procedure used, the timing for intervention, and the approach to intervention in this age group. This article reviews the important considerations for approaching procedures and offers suggestions for safe and effective methods of reliably producing the intended outcome.

Evaluation of physiologically based models of pregnancy and lactation for their application in children's health risk assessments

In today's scientific and regulatory climates, an increased emphasis is placed on the potential health impacts for children exposed either in utero or by nursing to drugs of abuse, pharmaceuticals, and industrial or consumer chemicals. As a result, there is a renewed interest in the development and application of biologically based computational models that can be used to predict the dosimetry (or ultimately response) in a developing embryo, fetus, or newborn. However, fundamental differences between animal and human development can create many unique challenges. For example, unlike models designed for adults,biologically based models of pre-and postnatal development must deal with rapidly changing growth dynamics (maternal embryonic, fetal, and neonatal), changes in the state of differentiation of developing tissues, uniquely expressed or uniquely functioning signal transduction or enzymatic pathways, and unusual routes of exposure (e.g., maternal-mediated placental transfer and lactation). In cases where these challenges are overcome or addressed, biological modeling will likely prove useful in assessments geared toward children's health, given the contributions that this approach has already made in cancer and non-cancer human health risk assessments. Therefore, the purpose of this review is to critically evaluate the current state of the art in physiologically based pharmacokinetic (PBPK) and pharmacodynamic (PD) modeling of the developing embryo, fetus, or neonate and to recommend potential steps that could be taken to improve their use in children's health risk assessments. The intent was not to recommend improvements to individual models per se, but to identify areas of research that could move the entire field forward. This analysis includes a brief summary of current risk assessment practices for developmental toxicity, with an overview of developmental biology as it relates to species-specific dosimetry. This summary should provide a general context for understanding the tension that exists in modeling between describing biological proceses in exquisite detail vs. the simplifications that are necessary due to lack of data (or through a sensitivity analysis, determined to be of little impact) to develop individual PBPK or PD models. For each of the previously published models covered in this review, a description of the underlying assumptions and model structures as well as the data and methods used in model development and validation are highlighted. Although several of the models attempted to describe target tissues in the developing embryo, fetus, or neonate of laboratory animals, extrapolations to humans were largely limited to maternal blood or milk concentrations. Future areas of research therefore are recommended to extend the already significant progress that has been made in this field and perhaps address many of the technical policy, and ethical issues surrounding various approaches for decreasing the uncertainty in extrapolating from animal models to human pregnancies or neonatal exposures.

Transdermal Xenobiotics in Newborn Skin

Newborn infants are regularly exposed to a wide variety of topical agents, including treatments for rashes, antimicrobial agents, solvents, and skin barriers or moisturizers. Premature and hospitalized infants are also exposed to topical iodine for antisepsis and to topical analgesic agents. The fact that most of these agents have not been specifically evaluated for use in infants has recently been recognized as a major public health concern. The epidermis of preterm infants is not fully developed, constituting an incomplete barrier to systemic absorption of topical agents. Thus, substances applied to the skin can have adverse systemic effects. Povidone-iodine and steroid creams have been associated with thyroid and hypothalamic-pituitary axis suppression, respectively, in premature infants. Application of topical EMLA (Eutectic Mixture of Local Anesthetics) for analgesia has been implicated in methemoglobinemia in premature infants. Exposure to natural latex in gloves and medical equipment may sensitize infants, leading to the development of airway hyperreactivity and other allergic manifestations. Therefore, it is advisable to limit skin exposure of premature infants to xenobiotics. Further work is required to define safe doses of common agents. In addition, transdermal administration of systemic medications, including methylxanthines, may be practical in premature infants.

[Pediatric dermatotherapy]

Dermatological therapy of children differs considerably from treatment of adults and poses a special challenge. Dermatological diseases often form idiosyncratic entities with a prognosis different from adults and must be treated appropriately. Consideration should also be given to the fact that children occasionally experience adverse reactions to drugs, which are not observed in adults. A selection of dermatological diseases and typical drug reactions are presented to illustrate the special features and differences between pediatric dermatotherapy and treatment of adults.

Absorption of sunscreens across human skin: an evaluation of commercial products for children and adults

AIMS

Topical sunscreens are routinely applied to the skin by a large percentage of the population. This study assessed the extent of absorption of a number of common chemical sunscreen agents into and through human skin following application of commercially available products.

METHODS

Sunscreen products were applied to excised human epidermis in Franz diffusion cells with the amount penetrating into and across the epidermis assessed by h.p.l.c. for 8 h following application.

RESULTS

All sunscreen agents investigated penetrated into the skin (0.25 g m-2 or 14% of applied dose), but only benzophenone-3 passed through the skin in significant amounts (0.08 g m-2 or 10% of the applied dose). With one exception, suncreen agents in corresponding products marketed for adults and children had similar skin penetration profiles.

CONCLUSIONS

Whilst limited absorption across the skin was observed for the majority of the sunscreens tested, benzophenone-3 demonstrated sufficiently high penetration to warrant further investigation of its continued application.

A survey of skin care practices for premature low birth weight infants

PURPOSE

To provide baseline information about current skin care practices in premature low birth weight infants (< 1,000 gm birth weight) in typical NICUs within the U.S.

DESIGN

Descriptive survey.

SAMPLE

104 hospitals with at least 2,500 deliveries per year and at least 20 Level III NICU beds.

MAIN OUTCOME VARIABLES

Environmental conditions, bathing practices and products, adhesive products used to secure IVs and endotracheal tubes, skin protectants used with diaper rash, treatment systems for fragile preterm skin, and treatment systems for denuded skin.

RESULTS

Most units surveyed based their premature low birth weight skin care protocols on a combination of gestational age and birth weight criteria. One-quarter of the units had no skin care protocols at all. Among the units, there was considerable practice variation with respect to common nursing procedures such as bathing, adhesive application, and wound care.

Neonatal skin and skin care

Infant skin differs from adult skin in several ways. These important differences place infants at increased risk for fluid electrolyte imbalance, thermal instability, skin damage, percutaneous infection, and percutaneous toxicity from topically applied agents. This article includes a review of skin development, as well as the details of current skin care practices in the neonatal nursery. A better understanding of the principles of infant skin care and a more uniform approach to skin care in the neonatal nursery can minimize risks and costs to this special population of patients.

The Neonatal Skin Risk Assessment Scale for predicting skin breakdown in neonates

An instrument was developed to assess neonates at risk for skin breakdown, based on the Braden Scale for Predicting Pressure Sore Risk in adults. Using such an instrument to predict, and thus prevent, skin breakdown could decrease costs associated with prolonged hospital stays in neonates. The Neonatal Skin Risk Assessment Scale (NSRAS) was piloted with 32 neonates. Reliability was high for the subscales of general physical condition, activity, and nutrition, but low in the other three subscales. For predictive validity, sensitivity was 83% and specificity was 81%. The NSRAS appears to be useful in predicting days most likely for skin breakdown to occur.