Low Allergenic Potential Research Articles

Coincident airway exposure to low-potency allergen and cytomegalovirus sensitizes for allergic airway disease by viral activation of migratory dendritic cells.

Despite a broad cell-type tropism, cytomegalovirus (CMV) is an evidentially pulmonary pathogen. Predilection for the lungs is of medical relevance in immunocompromised recipients of hematopoietic cell transplantation, in whom interstitial CMV pneumonia is a frequent and, if left untreated, fatal clinical manifestation of human CMV infection. A conceivable contribution of CMV to airway diseases of other etiology is an issue that so far attracted little medical attention. As the route of primary CMV infection upon host-to-host transmission in early childhood involves airway mucosa, coincidence of CMV airway infection and exposure to airborne environmental antigens is almost unavoidable. For investigating possible consequences of such a coincidence, we established a mouse model of airway co-exposure to CMV and ovalbumin (OVA) representing a protein antigen of an inherently low allergenic potential. Accordingly, intratracheal OVA exposure alone failed to sensitize for allergic airway disease (AAD) upon OVA aerosol challenge. In contrast, airway infection at the time of OVA sensitization predisposed for AAD that was characterized by airway inflammation, IgE secretion, thickening of airway epithelia, and goblet cell hyperplasia. This AAD histopathology was associated with a T helper type 2 (Th2) transcription profile in the lungs, including IL-4, IL-5, IL-9, and IL-25, known inducers of Th2-driven AAD. These symptoms were all prevented by a pre-challenge depletion of CD4+ T cells, but not of CD8+ T cells. As to the underlying mechanism, murine CMV activated migratory CD11b+ as well as CD103+ conventional dendritic cells (cDCs), which have been associated with Th2 cytokine-driven AAD and with antigen cross-presentation, respectively. This resulted in an enhanced OVA uptake and recruitment of the OVA-laden cDCs selectively to the draining tracheal lymph nodes for antigen presentation. We thus propose that CMV, through activation of migratory cDCs in the airway mucosa, can enhance the allergenic potential of otherwise poorly allergenic environmental protein antigens.

Functionality of the components from goat’s milk, recent advances for functional dairy products development and its implications on human health

The growing consumer interest in goat’s milk and dairy products is related to nutritive values and positive health benefits attached to these products. Goat’s milk is known for its lower allergenic potential and better digestibility, when compared to bovine milk, as well as the presence of health-promoting compounds. Therefore, goat milk can be used in the manufacture of a wide variety of products and can also be used as carrier for functional components, such as prebiotic substances or probiotic bacteria. Somein vivostudies have been carried out to explore its therapeutic potential and have shown excellent biological effects.However, probiotic/prebiotic research remains minimally explored regarding the functional aspects of goat dairy products. Thus, future studies using goat’s milk products as probiotic/prebiotic matrix could be assessed in several models in a similar fashion to what is studied with bovine milk.

Absence of human skin irritation and allergenic potential after repeated patch applications of a lamellar moisturizer.

SummaryBackgroundNew cosmetic products should undergo clinical evaluation for skin sensitization potential.ObjectivesTo assess the irritation and sensitization potential of a moisturizer containing lamellar structured lipids after repeated patch application in humans, using human repeated insult patch test methodology.MethodsThis 6‐week, single‐center, open‐label study compared a lamellar moisturizer with negative saline control in human subjects aged 18‐70 years and skin phototype (Fitzpatrick) classification I–IV. During an initial induction phase, semi‐occlusive multi‐test patches were applied to the skin of participants’ backs three times per week for 3 consecutive weeks; clinical assessments were performed per International Contact Dermatitis Research Group criteria. Participants subsequently underwent a challenge phase, where a new patch was applied to a contact‐naïve area of the skin to assess sensitization to the moisturizer.ResultsThe study commenced with 233 voluntary participants, 214 of whom completed the study and underwent the final dermatological assessment. Most participants (232/233; 99.6%) demonstrated negative patch test results. One participant had a positive reaction at the lamellar moisturizer application site, with visible erythema and edema (classified as an adverse event [AE]); however, this reaction was observed 24 hours after a reaction to another product in the patch test panel (a prototype cleanser). Importantly, no skin reactions were detected during the challenge phase. Two participants had AEs of mild contact dermatitis in the area of patch adhesive application during the induction phase. No serious AEs occurred during the study.ConclusionsThese findings suggest that the lamellar moisturizer has low irritant and allergenic potential.

Prospective Single-Center Observational Study of the Allergenic Potential of Mercromina Film and Other Common Antiseptics in Patients With Contact Dermatitis

IntroductionAlthough Mercromina Film and other topical antiseptics are widely used, they are not included in the standard series recommended by the Spanish Contact Dermatitis and Skin Allergy Research Group for testing suspected allergic contact dermatitis (ACD). Furthermore, no recent studies have investigated the allergenic potential of merbromin. ObjectiveTo determine the allergenic potential of merbromin and compare it with that of other topical antiseptics widely used in clinical practice, including povidone-iodine, chlorhexidine, and eosin. Material and methodsProspective single-center observational safety study of 105 patients with suspected ACD seen at the dermatology department of our hospital. ResultsOf the 105 patients studied, 1.9% had a positive patch test to merbromin and 12.4% were sensitized to povidone-iodine. The differences in the proportion of patients with ACD to Betadine Solución Dérmica (povidone-iodine) compared with the rest of the antiseptics was statistically significant (McNemar test, P<.05). No adverse reactions were observed in any of the patients. ConclusionsBased on the patch tests conducted, Mercromina Film has very low allergenic potential. The highest allergenic potential was observed for povidone-iodine.

Estudio observacional de seguridad, prospectivo y unicéntrico para determinar la capacidad alergogénica de Mercromina Film® y otros antisépticos de uso común en pacientes con dermatitis de contacto

IntroductionAlthough Mercromina Film and other topical antiseptics are widely used, they are not included in the standard series recommended by the Spanish Contact Dermatitis and Skin Allergy Research Group for testing suspected allergic contact dermatitis (ACD). Furthermore, no recent studies have investigated the allergenic potential of merbromin. ObjectiveTo determine the allergenic potential of merbromin and compare it with that of other topical antiseptics widely used in clinical practice, including povidone-iodine, chlorhexidine, and eosin. Material and methodsProspective single-center observational safety study of 105 patients with suspected ACD seen at the dermatology department of our hospital. ResultsOf the 105 patients studied, 1.9% had a positive patch test to merbromin and 12.4% were sensitized to povidone-iodine. The differences in the proportion of patients with ACD to Betadine Solución Dérmica (povidone-iodine) compared with the rest of the antiseptics was statistically significant (McNemar test, P<.05). No adverse reactions were observed in any of the patients. ConclusionsBased on the patch tests conducted, Mercromina Film has very low allergenic potential. The highest allergenic potential was observed for povidone-iodine.

Identification of Proteases and Protease Inhibitors in Allergenic and Non-Allergenic Pollen.

Pollen is one of the most common causes of allergy worldwide, making the study of their molecular composition crucial for the advancement of allergy research. Despite substantial efforts in this field, it is not yet clear why some plant pollens strongly provoke allergies while others do not. However, proteases and protease inhibitors from allergen sources are known to play an important role in the development of pollen allergies. In this study, we aim to uncover differences in the transcriptional pattern of proteases and protease inhibitors in Betula verrucosa and Pinus sylvestris pollen as models for high and low allergenic potential, respectively. We applied RNA sequencing to Betula verrucosa and Pinus sylvestris pollen. After de-novo assembly we derived general functional profiles of the protein coding transcripts. By utilization of domain based functional annotation we identified potential proteases and protease inhibitors and compared their expression in the two types of pollen. Functional profiles are highly similar between Betula verrucosa and Pinus sylvestris pollen. Both pollen contain proteases and inhibitors from 53 and 7 Pfam families, respectively. Some of the members comprised within those families are implicated in facilitating allergen entry, while others are known allergens themselves. Our work revealed several candidate proteins which, with further investigation, represent exciting new leads in elucidating the process behind allergic sensitization.

Development and validation of an analytical method using High Performance Liquid Chromatography (HPLC) to determine ethyl butylacetylaminopropionate in topical repellent formulations

ABSTRACT Diseases caused by insects are frequent in poor countries, leading to epidemic scenarios in urban areas; e.g., Dengue, Zika and Chikungunya. For this reason, the development of a safe and efficient topical formulation is essential. Ethyl butylacetylaminopropionate (EB) is a mosquito repellent developed by Merck, which is used in products for adults, children and especially babies, due to its low allergenic potential. The aim of this work was to validate an analytical methodology to quantify EB in a new poloxamer-based formulation by high-performance liquid chromatography (HPLC). The quantification methodology was performed at 40 oC using a Kromasil reverse-phase column (C18), with the dimensions of 250 x 4.6 mm. The mobile phase was acetonitrile:water (1:1) at a 1.0 mL/min flow-rate. The detector wavelength was set at 218 nm to detect EB. The methodology was considered validated since the results indicated linearity (R2>0.99), specificity, selectivity, precision and accuracy (active recovery between 98% and 102%). It also presented limits of detection and quantification of 0.255 µg/mL and 0.849 µg/mL, respectively. The present study demonstrated the EB vehiculated in poloxamer gel is promising as a new insect repellent formulation, since it could be quantified and quality control evaluated.

Transparent crosslinked ultrashort peptide hydrogel dressing with high shape-fidelity accelerates healing of full-thickness excision wounds.

Wound healing is a major burden of healthcare systems worldwide and hydrogel dressings offer a moist environment conducive to healing. We describe cysteine-containing ultrashort peptides that self-assemble spontaneously into hydrogels. After disulfide crosslinking, the optically-transparent hydrogels became significantly stiffer and exhibited high shape fidelity. The peptide sequence (LIVAGKC or LK6C) was then chosen for evaluation on mice with full-thickness excision wounds. Crosslinked LK6C hydrogels are handled easily with forceps during surgical procedures and offer an improvement over our earlier study of a non-crosslinked peptide hydrogel for burn wounds. LK6C showed low allergenic potential and failed to provoke any sensitivity when administered to guinea pigs in the Magnusson-Kligman maximization test. When applied topically as a dressing, the medium-infused LK6C hydrogel accelerated re-epithelialization compared to controls. The peptide hydrogel is thus safe for topical application and promotes a superior rate and quality of wound healing.

Development and characterization of repellent formulations based on nanostructured hydrogels

Diseases caused by insects could lead to epidemic scenarios in urban areas and insect repellents are a shield against a wide range of insects, but they need to be safe without compromising efficacy. Ethyl butylacetylaminopropionate (EB) is a synthetic mosquito repellent, which could be used in products for adults and children due to its low-allergenic potential. The aim of this study was to develop and characterize EB and Poloxamer 407 nanoemulsions regarding their droplets mean size, pH, rheological properties, cytotoxicity and in vitro permeation profile. The developed formulations (F1 with 12.5% of EB and F2 with 25% of EB) were compared with a commercial formulation containing 12.5% of EB. Droplets mean size was determined by DLS, and for both nanoemulsions they were around 200 nm; however, the commercial formulation presented a droplets mean size of 10 nm, which could contribute to its high permeation. F1 and F2 presented a gel-like behavior, however F2 presented lower viscosity due to the presence of more EB between the polymer chains preventing them to interact with each other. Also, F2 was less retained by the epidermis when compared to F1 probably due to its lower viscosity. For the cytotoxicity assay only F2, which presented the highest concentration of EB was tested, and it was not toxic to the cells. This result could be also extended to F1 which presented half the EB concentration. The present study demonstrated that EB and Poloxamer 407 nanoemulsions are promising as new insect-repellent formulations.

Impact of Wild Loci on the Allergenic Potential of Cultivated Tomato Fruits.

Tomato (Solanum lycopersicum) is one of the most extensively consumed vegetables but, unfortunately, it is also able to induce allergic reactions. In the past, it has been shown that the choice of tomato cultivar significantly influenced the allergic reaction of tomato allergic subjects. In this study we investigated the allergenic potential of the cultivated tomato line M82 and of two selected lines carrying small chromosome regions from the wild species Solanum pennellii (i.e. IL7-3 and IL12-4). We evaluated the positive interactions of IgEs of allergic subjects in order to investigate the different allergenic potential of the lines under investigation. We used proteomic analyses in order to identify putative tomato allergens. In addition, bioinformatic and transcriptomic approaches were applied in order to analyse the structure and the expression profiles of the identified allergen-encoding genes. These analyses demonstrated that fruits harvested from the two selected introgression lines harbour a different allergenic potential as those from the cultivated genotype M82. The different allergenicity found within the three lines was mostly due to differences in the IgE recognition of a polygalacturonase enzyme (46 kDa), one of the major tomato allergens, and of a pectin methylesterase (34 kDa); both the proteins were more immunoreactive in IL7-3 compared to IL12-4 and M82. The observed differences in the allergenic potential were mostly due to line-dependent translational control or post-translational modifications of the allergens. We demonstrated, for the first time, that the introgression from a wild species (S. pennellii) in the genomic background of a cultivated tomato line influences the allergenic properties of the fruits. Our findings could support the isolation of favorable wild loci promoting low allergenic potential in tomato.

Protein expression and genetic variability of canine Can f 1 in golden and Labrador retriever service dogs.

BackgroundValued for trainability in diverse tasks, dogs are the primary service animal used to assist individuals with disabilities. Despite their utility, many people in need of service dogs are sensitive to the primary dog allergen, Can f 1, encoded by the Lipocalin 1 gene (LCN1). Several organizations specifically breed service dogs to meet special needs and would like to reduce allergenic potential if possible. In this study, we evaluated the expression of Can f 1 protein and the inherent variability of LCN1 in two breeds used extensively as service dogs. Saliva samples from equal numbers of male and female Labrador retrievers (n = 12), golden retrievers (n = 12), and Labrador-golden crosses (n = 12) were collected 1 h after the morning meal. Can f 1 protein concentrations in the saliva were measured by ELISA, and the LCN1 5′ and 3′ UTRs and exons sequenced.ResultsThere was no sex effect (p > 0.2) nor time-of-day effect; however, Can f 1 protein levels varied by breed with Labrador retrievers being lower than golden retrievers (3.18 ± 0.51 and 5.35 ± 0.52 μg/ml, respectively, p < 0.0075), and the Labrador-golden crosses having intermediate levels (3.77 ± 0.48 μg/ml). Although several novel SNPs were identified in LCN1, there were no significant breed-specific sequence differences in the gene and no association of LCN1 genotypes with Can f 1 expression.ConclusionsAs service dogs, Labrador retrievers likely have lower allergenic potential and, though there were no DNA sequence differences identified, classical genetic selection on the estimated breeding values associated with salivary Can f 1 expression may further reduce that potential.Electronic supplementary materialThe online version of this article (doi:10.1186/s40575-016-0031-3) contains supplementary material, which is available to authorized users.

A review of allergoid immunotherapy: is cat allergy a suitable target?

To modify the course of allergy, different types of specific allergen immunotherapy have been developed such as sublingual immunotherapy and subcutaneous immunotherapy with native allergens or subcutaneous immunotherapy with polymerized allergoids. However, the optimal specific immunotherapy, especially for cat allergy, remains undetermined. Few studies investigating immunotherapy in cat allergy have been published, and the risk of serious adverse reactions and systemic reactions has often been an important issue. Monomeric allergoids have lower allergenic potential while their immunogenicity remains constant, resulting in excellent safety with notable efficacy. Specific immunotherapy with monomeric allergoids could, therefore, be of high value, especially in cat allergy as well as other types of allergy, and bring relief to a great community of patients.

DETERMINATION OF PHYSICOCHEMICAL, IMMUNOCHEMICAL AND ANTIOXIDANT PROPERTIES, TOXICOLOGICAL AND HYGIENIC ASSESSMENT OF WHEY PROTEIN COMCENTRATE AND ITS HYDROLYSATE

Enzymatic hydrolysis of whey proteins is aimed to obtain products with low allergenic potential and high nutritional value. Whey peptides are protein fraction that possesses a variety of physicochemical, immunochemical and bioactive properties (antioxidant, antibacterial, immunomodulatory effects). Controlled parameters of enzymatic hydrolysates are the degree of hydrolysis of protein substrates, peptide composition, residual antigenicity, antioxidant capacity, etc. The purpose of this work is to characterize peptide profile, antigenicity and free radical scavenging properties of experimental hydrolysate sample, toxicological and hygienic assessment of its impact on a test object (infusoria Tetrahymena pyriformis). The research of properties of whey proteins and their enzymatic hydrolysates was conducted using classical and modern methodological approaches: SDS electrophoresis in polyacrylamide gel, HPLC, mass-spectrometry, competitive ELISA, TEAC (Trolox Equivalent Capacity Assay) technique. Peptide composition, antigenic and antioxidant properties of obtained enzymatic hydrolysate were determined, toxicity of raw and digested whey proteins were examined. We established that the investigated hydrolysate sample falls under the category of partial hydrolysates for functional products according to its physicochemical, immunochemical, free radical scavenging and organoleptic properties. According to the results of toxicological and hygienic assessment using T. pyriformis model, whey protein concentrate and its hydrolysates are non-toxic and do not possess cumulative properties. Thus, we obtained partial enzymatic hydrolysate of whey proteins from milk, which can be used as physiologically active component in the development of new specialized food.

Characterization of an Equine α-S2-Casein Variant Due to a 1.3 kb Deletion Spanning Two Coding Exons.

The production and consumption of mare’s milk in Europe has gained importance, mainly based on positive health effects and a lower allergenic potential as compared to cows’ milk. The allergenicity of milk is to a certain extent affected by different genetic variants. In classical dairy species, much research has been conducted into the genetic variability of milk proteins, but the knowledge in horses is scarce. Here, we characterize two major forms of equine αS2-casein arising from genomic 1.3 kb in-frame deletion involving two coding exons, one of which represents an equid specific duplication. Findings at the DNA-level have been verified by cDNA sequencing from horse milk of mares with different genotypes. At the protein-level, we were able to show by SDS-page and in-gel digestion with subsequent LC-MS analysis that both proteins are actually expressed. The comparison with published sequences of other equids revealed that the deletion has probably occurred before the ancestor of present-day asses and zebras diverged from the horse lineage.

Evaluation of biodegradable polymer conduits – poly(l-lactic acid) – for guiding sciatic nerve regeneration in mice

Polymeric biomaterials are often used for stimulating nerve regeneration. Among different conduits, poly(lactide acid) – PLA polymer is considered to be a good substrate due to its biocompatibility and resorbable characteristics. This polymer is an aliphatic polyester which has been mostly used in biomedical application. It is an organic compound with low allergenic potential, low toxicity, high biocompatibility and predictable kinetics of degradation. In this study we fabricated and evaluated a PLA microporous hollow fiber as a conduit for its ability to bridge a nerve gap in a mouse sciatic nerve injury model. The PLA conduit was prepared from a polymer solution, throughout extrusion technique. The left sciatic nerve of C57BL/6 mouse was transected and the nerve stumps were placed into a resorbable PLA (PLA group) or a PCL conduit (PCL group), n=5 each group. We have also used another group in which the nerves were repaired by autograft (autograft group, n=5). Motor function was analyzed according to sciatic functional index (SFI). After 56days, the regenerated nerves were processed for light and electron microscopy and morphometric analyses were performed. A quantitative analysis of regenerated nerves showed significant increase in the number of myelinated fibers and blood vessels in animals that received PLA conduit. The PLA group exhibited better overall tissue organization compared to other groups. Presenting well-organized bundles, many regenerating clusters composed of preserved nerve fibers surrounded by layers of compacted perineurium-like cells. Also the SFI revealed a significant improvement in functional recovery. This work suggests that PLA conduits are suitable substrate for cell survival and it provides an effective strategy to be used to support axonal growth becoming a potential alternative to autograft.

Development of an Animal Model to Evaluate the Allergenicity of Food Allergens

Scope: Considering the increasing numbers of patients suffering from food allergy (FA) as well as the great variety of novel foods and food compositions, an unmet need exists for the development of preclinical approaches to characterize the allergenic potential of proteins. The aim of our study was to evaluate the allergenicity of different food allergens in a rat model. Methods: Brown Norway rats were sensitized to protein extracts (RuBisCO, apple, soy, peanut, garden pea) or ovalbumin (OVA) combined with Bordetella pertussis and aluminium hydroxide, followed by oral allergen challenges. Results: Allergen-specific serum immunoglobulin production and the proliferation of mononuclear cells from spleen confirmed sensitization. To assess functional alterations in the gut, intestinal permeability was measured, which increased in sensitized and challenged animals compared to non-sensitized controls. Allergens with high allergenic potential (peanut, OVA, soy) caused a stronger immunological response than allergens with low allergenic potential, such as RuBisCO and apple. Moreover, the immunological responses were reduced when using boiled instead of raw soy and pea proteins. Conclusion: This model mimics key features of FA and facilitates investigating the allergenicity of allergens in novel food or food compositions in vivo.

Contact allergy to ingredients of hair cosmetics – a comparison of female hairdressers and clients based on IVDK 2007–2012 data

Cosmetics for bleaching, waving/relaxing and dyeing hair contain well-known allergens, leading to a substantial number of cases of allergic contact dermatitis. To compare the frequency of important contact allergens (i) between two distinct groups of exposed patients, and (ii) with previous surveillance data. On the basis of data collected by the Information Network of Departments of Dermatology (IVDK; www.ivkd.org) between 2007 and 2012 in 824 female hairdressers and 2067 female clients, the current spectrum of contact sensitization to ingredients of hair cosmetics, as contained in different pertinent series, is described. A similar burden of sensitization as in previous analyses was observed, but with some increase in sensitization to oxidative hair dye components in clients. Some allergens mainly affected hairdressers, such as ammonium persulfate (18.7% positive) and glyceryl monothioglycolate (GMTG; still 4.7% positive, with a few cases also in young hairdressers, despite removal from the German market). Hair dyes remain important contact allergens, despite various attempts by the cosmetic industry to introduce hair dyes with lower allergenic potential. The re-emergence of GMTG as an occupational allergen should be considered as a warning signal ('sentinel event') prompting close monitoring.

FILTROS SOLARES E FOTOPROTETORES – UMA REVISÃO

A exposição excessiva ao sol e sem proteção representa um dos maiores riscos para o desenvolvimento de tumores malignos. O uso de substâncias para proteger a pele, como os filtros solares, tem a atenção do mercado. O desenvolvimento de fotoprotetores com eficácia e segurança é obtido através do conhecimento de seus mecanismos de ação e formulações. Os filtros solares e fotoprotetores, além de proteger contra os raios ultravioletas, podem hidratar e rejuvenescer a pele. O estudo é uma revisão bibliográfica sobre filtros solares e fotoprotetores, com objetivos de revisar os fenômenos que envolvem os filtros solares, apresentar as classificações, o mecanismo de ação e os métodos de avaliação da proteção solar, e por fim, evidenciar a importância do uso do filtro solar na prevenção do fotoenvelhecimento e do câncer de pele. Ressalta-se que o uso de combinações como de filtros inorgânicos com orgânicos aumentam o espectro de proteção, permitindo maior FPS com redução do custo e a potência de reações irritantes. A associação de óxido de zinco com dióxido de titânio permite obter formulações com baixo potencial alergênico e irritante, podendo ser utilizada por indivíduos mais sensíveis. Estas combinações representam o avanço da tecnologia e possibilidades para novos produtos no mercado com segurança.

Microbiological quality and safety of goat's milk from one farm

In recent years, the popularity of goat’s milk and goat’s milk products has been growing in the Czech Republic, especially for its low allergenic potential and good digestibility. This study focused on the assessment of the microbiological quality and safety of raw and heat-treated goat’s milk. During the lactation period, total of 48 samples of raw and 40 samples of pasteurized goat’s milk were collected on a goat’s farm in the South Moravian Region of the Czech Republic. Quantitative analysis was performed to determine the total plate count (TPC) and coagulase-positive (CP) staphylococci count. The presence of E. coli including E. coli O157, CP staphylococci, B. cereus, L. monocytogenes, Salmonella spp., and Campylobacter spp. was detected. The monthly average TPC ranged from 4.53 to 5.21 log CFU.ml−1 in raw milk and from 2.36 to 3.71 log CFU.ml−1 in pasteurized milk. Thirty (75.0%) S. aureus isolates from raw milk carried the sec gene, two (5.0%) were positive for the genes seb, seg, sei, and one (2.5%) harboured the seg and sei genes. Pasteurized goat’s milk samples yielded a single isolate of S. aureus carriyng the sec gene. One isolate of E. coli serotype O156 producing ST1 toxin was recovered from raw milk. B. cereus was detected only in two pasteurized goat’s milk samples. Any other pathogens monitored were not detected. In this study, shigatoxin-producing E. coli O156 was detected in raw goat’s milk for the first time in the Czech Republic.

Safety and efficacy of personal care products containing colloidal oatmeal

BackgroundColloidal oatmeal is a natural ingredient used in the formulation of a range of personal care products for relief of skin dryness and itchiness. It is also used as an adjunctive product in atopic dermatitis. The safety of personal care products used on vulnerable skin is of particular importance and the risk of developing further skin irritations and/or allergies should be minimized.MethodsIn a series of studies, we tested the safety of personal care products containing oatmeal (creams, cleansers, lotions) by assessing their irritant/allergenic potential on repeat insult patch testing, in safety-in-use and ocular studies using subjects with nonsensitive and sensitive skin. We also tested the skin moisturizing and repair properties of an oatmeal-containing skin care product for dry skin.ResultsWe found that oatmeal-containing personal care products had very low irritant potential as well as a very low allergenic sensitization potential. Low-level reactions were documented in 1.0% of subjects during the induction phase of repeat insult patch testing; one of 2291 subjects developed a persistent but doubtful low-level reaction involving edema during the challenge phase in repeat insult patch testing. No allergies were reported by 80 subjects after patch testing after in-use application. Sustained skin moisturizing was documented in subjects with dry skin that lasted up to 2 weeks after product discontinuation.ConclusionOur results demonstrate that colloidal oatmeal is a safe and effective ingredient in personal care products. No allergies were reported by consumers of 445,820 products sold during a 3-year period.