No full-text available
To read the full-text of this research,
you can request a copy directly from the author.
Scaly skin and bath pH: Rediscovering baking soda
... Bathing in alkaline seawater (pH 8.1) or baking soda for 30-60 minutes at least once weekly can facilitate scale removal. 3 Some patients also find colloidal oatmeal and salt additives in their bath and hydrotherapy with bubbles helpful ...
Congenital ichthyoses are a group of hereditary disorders of keratinization that are challenging to treat. Affected individuals suffer not only from thickening of the skin but also associated complications such as growth restriction, hearing and eye complications, infections, and thermodysregulation. This clinical review provides a practical roadmap to the longitudinal care of patients with ichthyosis with both general and age- and disease-specific recommendations. The allure of pathogenesis-based and targeted treatments for these monogenetic severe but orphan conditions shines bright as dermatological therapies enter a new era.
... Careful use of scissors for partially adherent large scales and sharp debridement with scalpels of thickened palms and soles may also be needed. Salts, oils or baking soda can be added to provide additional hydration and promote exfoliation 198 . Highly diluted sodium hypochlorite (bleach) has also been added to reduce odour due to microbial colonization in some patients 13 . ...
The ichthyoses are a large, heterogeneous group of skin cornification disorders. They can be inherited or acquired, and result in defective keratinocyte differentiation and abnormal epidermal barrier formation. The resultant skin barrier dysfunction leads to increased transepidermal water loss and inflammation. Disordered cornification is clinically characterized by skin scaling with various degrees of thickening, desquamation (peeling) and erythema (redness). Regardless of the type of ichthyosis, many patients suffer from itching, recurrent infections, sweating impairment (hypohidrosis) with heat intolerance, and diverse ocular, hearing and nutritional complications that should be monitored periodically. The characteristic clinical features are considered to be a homeostatic attempt to repair the skin barrier, but heterogeneous clinical presentation and imperfect phenotype–genotype correlation hinder diagnosis. An accurate molecular diagnosis is, however, crucial for predicting prognosis and providing appropriate genetic counselling. Most ichthyoses severely affect patient quality of life and, in severe forms, may cause considerable disability and even death. So far, treatment provides only symptomatic relief. It is lifelong, expensive, time-consuming, and often provides disappointing results. A better understanding of the molecular mechanisms that underlie these conditions is essential for designing pathogenesis-driven and patient-tailored innovative therapeutic solutions.
Editor abstract: The ichthyoses are a group of dermatological disorders characterized by generalized scaly, erythematous skin, accompanied by epidermal barrier function disruptions. This Primer by Gutiérrez-Cerrajero and colleagues summarizes the epidemiology, mechanisms, diagnosis and treatment of ichthyosis, and discusses patient quality of life and open research questions for this condition.
... Studies have shown that magnesium found in epsom salt can be absorbed by the skin, which can provide a relief from skin condition [13]. Additionally, baking soda is now being revisited as a therapy in skin care for scaly skin and are also added in soap as an alternative to caustic soda [14,15]. ...
Purpose:
This study investigated physicochemical properties and antimicrobial performance of soaps formulated from natural ingredients with the intention to apply them as alternative deodorizing soaps in personal care products.
Methods:
Soaps were formulated with natural ingredients including lemon, aloe vera and honey. Foam stability and capac-ity tests as well as pH were determined for the soaps. Deodorizing effectiveness of the soaps was tested theoretically using minimum inhibitory concentration (MIC) test by screening them against pathogenic organisms causing body odour: bacteria (Staphylococcus aureus, Candida albican, Staphylococcus hominis, Strephotococcus mutant, Staphylococcus epidemidis) and fungi (Tinnea annum, Tinneapedis and Trycrophyton rubrum) using agar well diffusion method and poisoned food technique respectively while having Dettol soap and ketoconazole as controls.
Results:
The soaps had a maximum foam capacity of 150% and foam stability of 100% with pH values in the range of 9.3–9.8 and inhibited the growth of the tested organisms for up to 6days at 0.1g/ml concentration.
Conclusion:
The soaps are mildly alkaline, possess good foaming capacity and stability and have considerably significant antimicrobial properties that can impede the growth of the organisms.
... Systemic and topical antibiotics with antiseptic washes can be used as needed to control infection [5]. Sodium bicarbonate bath also can help exfoliate scales and reduce malodorous skin [3,12]. Dilute bleach baths may be helpful. ...
Epidermolytic ichthyosis (EI, OMIM 113800) is a rare autosomal dominant keratinization disorder that is caused by keratin 1 or keratin 10 gene mutation. It can be classified clinically based on the presence of palmoplantar hyperkeratosis involvement and extent of skin involvement. The diagnosis is made by clinical and histopathological examinations that can be confirmed by genetic testing. We present a 2-year- old girl who presented with erythematous and thick scaling skin. Her condition began at birth as multiple flaccid blisters that would easily break into erosions. There was no history of similar condition nor consanguinity within her family. Skin examination revealed diffuse erythematous skin covered with thick scales and erosion, predominantly on her face, extremities, palms, and soles. The skin histopathology examination showed diffuse parakeratosis with vacuolar and granular degeneration within granular and spinous layers along the epidermis. She was diagnosed with generalized EI with palmoplantar hyperkeratosis based on the clinical and histopathological examinations. Clinical improvement was observed after a one-month treatment with mupirocin cream, sodium bicarbonate bath, and moisturizer after bathing.
... Hence, the efficiency of CLNVs to hold the core capsaicinoids were evaluated over 24 h in 0.3% Tween 80 aqueous solution, as the release medium [38]. The pH of the release medium is 5.5, the optimal pH of the skin [39]. ...
The current work aimed to fabricate a rice bran phospholipid-based nanovesicular system for oral and topical delivery of capsaicinoids from Capsicum annuum. Using a modified thin film-hydration method, capsaicinoid-loaded nanovesicles (CLNVs) with encapsulation efficiency of 92.31 ± 5.35% and a mean diameter of 134 ± 2 nm, were produced. Based on in vitro release studies, the produced CLNVs exhibited a slow and limited release in both simulated salivary and gastric fluids, and selective release in simulated intestinal fluid, suggesting the opportunity for targeting release via the gastro-intestinal tract during oral delivery. Furthermore, the observed limited release of capsaicinoids in surfactant solution is a desirable property for topical delivery formulations. The fabricated delivery vehicle has also shown a masked and reduced irritation effect that co-occur with the strong anti-inflammatory activity of the capsaicinoids. Using a modified duck egg chorioallantoic membrane (CAM) assays, it was demonstrated that encapsulation into nanovesicles was able to reduce the irritancy of capsaicinoids by almost 50% and, at the same time, improve the anti-inflammatory activity by up to 10 folds. These results demonstrated the potential of CLNVs to be developed as oral and topical delivery systems for capsaicinoids.
... A ausência de expansibilidade torácica causada pela falta de elasticidade da pele (28) pode favorecer a insuficiência respiratória no recém-nascido com o agravo em estudo. Nestes neonatos, a intubação e ventilação mecânica devem ser realizadas de forma criteriosa (29) . ...
RESUMO Objetivo: Apresentar os cuidados de enfermagem de um recém-nascido com Ictiose Lamelar internado na unidade de terapia intensiva neonatal de hospital público infantil, em município do estado do Paraná, Brasil. Método: Pesquisa de abordagem qualitativa, metodologia de Estudo de Caso, na qual foi explorado um caso real em sistema delimitado, um estudo intralocal, com coleta de dados de múltiplas fontes de informações, em 66 dias de internação, em 2016. Resultados: Os cuidados de enfermagem presentes no protocolo basearam-se em: manter a integridade da pele por meio de hidratação e lubrificação contínua com emolientes, controle da temperatura, nutrição e prevenção de infecções secundárias. Conclusão: Mediante o estudo do caso, afirma-se que a implementação do Processo de Enfermagem, sobretudo do plano de cuidados, foi essencial para o sucesso multidisciplinar do tratamento. Houve melhora da pele e mucosas, prevenção de infecções, culminando com condições favoráveis de sobrevida e autonomia dos pais para os cuidados em domicílio.
... The cause of this improvement is not clear, so far. It has been hypothesized that the most important factor is the basic pH created by SB dissolved in water, which should have a keratolytic action or play a role in activating some molecules involved in the disease or exert an action on the skin microbiome [22]. As the skin microbiome is typically altered in psoriasis [23], some authors showed that psoriatic subjects treated with La Roche-Posay spa water, rich in selenium, had a net improvement in lesions due to changes induced in the microbiome by this water [24]. ...
Introduction
Psoriasis is a chronic inflammatory disease characterized by the presence of erythematosquamous lesions. A wide variety of topical treatments for therapy of this pathology are available, including sodium bicarbonate (SB). A few papers reported in literature focus on use of SB baths for treatment of psoriasis, but none assess evidence concerning the efficacy of SB topical preparations. This study aimed to determine the effectiveness of a galenic SB in lanette vax formulation compared with lanette vax base in mild to moderate stable plaque psoriasis.
Methods
A randomized, double-blind, intrapatient, controlled study was performed in 28 days. Thirty patients of both genders were selected for testing. A blinded investigator evaluated the patients’ psoriasis using a modified Psoriasis Area and Severity Index (PASI), body surface area (BSA), and objective parameters using sensors (Multiprobe Adapter MPA5; Courage & Khazaka Electronic GmbH, Cologne, Germany).
Results
Data analysis of objective parameters highlighted that use of the SB topical preparation led to no improvement in skin hydration, no reduction in transepidermal water loss, and no decrease of erythema. The modified PASI and BSA did not change from baseline.
Conclusions
The results obtained show that use of the studied product did not improve psoriatic lesions.
... preparations, baking soda (3-6g/1L) or saltwater baths (normal saline 0.9%) can provide additional benefits(10,(38)(39)(40). Antiseptics should not be used routinely, except in CI with recurrent skin infections such as Keratitis-Ichthyosis-Deafness (KID) syndrome or Netherton syndrome (NS). ...
These guidelines for the management of congenital ichthyoses have been developed by a multidisciplinary group of European experts following a systematic review of the current literature, an expert conference held in Toulouse in 2016, and a consensus on the discussions. They summarize evidence and expert‐based recommendations and intend to help clinicians with the management of these rare and often complex diseases. These guidelines comprise two sections. This is Part one, covering topical therapies, systemic therapies, psychosocial management, communicating the diagnosis and genetic counselling.
This article is protected by copyright. All rights reserved.
... We generally recommend this treatment only for patients ≥ 1 year of age; for infants/ toddlers, the concentration should be halved (approximately 3 g per liter). To simplify matters, commercially available baking soda can be used instead of sodium hydrogen carbonate [ 17,18,25 ] . ...
Ichthyoses are a group of rare genetic skin disorders that pose numerous clinical challenges, in particular with respect to the correct diagnosis and appropriate management. The present update of the German ichthyosis guidelines addresses recent diagnostic advances that have resulted in the Sorèze consensus classification. In this context, we provide an updated diagnostic algorithm, taking into account clinical features as well as the molecular genetic basis of these disorders. Moreover, we highlight current therapeutic approaches such as psychosocial support, balneotherapy, mechanical scale removal, topical therapy, and systemic retinoid therapy. General aspects such as the indication for physical therapy, ergotherapy, or genetic counseling are also discussed. The present update was consented by an interdisciplinary consensus conference that included dermatologists, pediatricians, human geneticists, and natural scientists as well as representatives of the German patient support organization Selbsthilfe Ichthyose e. V.
... The gauze can be applied as a wet wrap, occluded with a plastic wrap layer for 10 to 20 minutes. 23 A bland emollient should be applied immediately after wet wrap removal. Products, such as petrolatum jelly, extra virgin coconut oil, and sunflower seed oil, are considered safe and may even possess antimicrobial properties. ...
Harlequin ichthyosis (HI) is the most severe phenotype of the autosomal recessive congenital ichthyoses. HI is caused by mutations in the lipid transporter adenosine triphosphate binding cassette A 12 (ABCA12). Neonates are born with a distinct clinical appearance, encased in a dense, platelike keratotic scale separated by deep erythematous fissures. Facial features are distorted by severe ectropion, eclabium, flattened nose, and rudimentary ears. Skin barrier function is markedly impaired, which can lead to hypernatremic dehydration, impaired thermoregulation, increased metabolic demands, and increased risk of respiratory dysfunction and infection. Historically, infants with HI did not survive beyond the neonatal period; however, recent advances in neonatal intensive care and coordinated multidisciplinary management have greatly improved survival. In this review, the authors combine the growing HI literature with their collective experiences to provide a comprehensive review of the management of neonates with HI.
Purpose of review:
This review focuses on the presentation and management of ichthyoses and highlights recent advances in treatment that hold promise for better targeted therapy.
Recent findings:
The ichthyoses are a group of rare genetic diseases with a wide phenotypic spectrum, characterized most often by generalized hyperkeratosis and scaling with variable erythema. The highly visible scaling and frequent itch contribute to decreased quality of life. Management for ichthyosis focuses on symptomatic relief and scale reduction with emollients, keratolytics, and retinoids. Recent advances in immune profiling and genotype-phenotype mapping have increased understanding of ichthyosis and shifted focus to pathogenesis-based targeted therapies with emerging biologics, small molecular inhibitors, and gene therapy.
Summary:
This article discusses clinical assessment and genotyping to make the diagnosis of specific forms of ichthyosis, provides guidance for management, and reviews new treatment options with systemic agents.
HI is a rare skin disorder. It follows autosomal recessive mode of
inheritance. Prenatal diagnosis should be offered to women with
previously affected babies. An understanding of the ABCA12
mutation and skin barrier disruption provides a basis for therapy.
The surviving children are now in their teenage years, with several
in their twenties display dry, reddened skin, which may be covered
by large thin scales, and sparse hair.
Harlequin ichthyosis is the most severe form of autosomal recessive congenital ichthyosis. The affected neonate is born with a
massive, horny shell of dense, plate like scale and contraction abnormalities of the eyes, ears, mouth. HI case treated with
acitretin, focusing on the multi-faceted management of the disease. It is usually treated with supportive care and prenatal
diagnosis for early findings. The prognosis improves once the baby survives the first few weeks. Physical development may be
delayed by the abnormal calorie needs their skin function demands, but mental and intellectual developments are expected to be
normal
The heterogeneous and large group of ichthyoses is highly relevant for neonatologists, paediatric dermatologists and paediatricians. The diseases are characterized by generalized hyperkeratosis and scaling. Nonsyndromic types of ichthyosis such as ichthyosis vulgaris, autosomal recessive congenital ichthyosis or keratinopathic ichthyosis can be distinguished from syndromic ichthyoses, e.g. Sjögren–Larsson or Chanarin–Dorfman syndrome. Management of the diseases is symptomatic and requires a multidisciplinary approach. This chapter follows the ichthyosis classification of Sorèze 2009 and discusses clinical findings, pathogenesis, genetics, as well as diagnostics and treatment options.
Zusammenfassung
Ichthyosen sind seltene genetische Hautkrankheiten, die den Kliniker vor mannigfache Herausforderungen stellen, insbesondere in Bezug auf das Stellen einer zutreffenden Diagnose und einer angemessenen therapeutischen Betreuung. Mit dieser Aktualisierung der deutschen Ichthyosis‐Leitlinie berücksichtigen wir jüngste diagnostische Fortschritte, die in die Konsensus‐Klassifikation von Sorèze mündeten und erarbeiten einen aktuellen Diagnose‐Algorithmus, der sowohl das klinische Bild als auch die Molekulargenetik dieser Erkrankungen berücksichtigt. Darüber hinaus wird der heutige Wissensstand bezüglich therapeutischer Ansätze wie psychosozialer Unterstützung, Balneotherapie, mechanischer Schuppenlösung, topischer Salbentherapie und Systemtherapie mit Retinoiden erläutert und es werden allgemeine Aspekte wie die Indikation für Physiotherapie, Ergotherapie oder die Notwendigkeit einer umfassenden genetischen Beratung diskutiert. Diese Aktualisierung der deutschen Ichthyosis‐Leitlinie wurde durch eine interdisziplinär besetzte Leitlinienkonferenz verabschiedet, an der Dermatologen, Kinderärzte, Humangenetiker und Naturwissenschaftler teilnahmen und in die die deutsche Patientenorganisation Selbsthilfe Ichthyose e. V. eingebunden war.
The majority of keratinization disorders are referred to as Mendelian disorders of cornification. This is a very broad group, clinically characterized by hyperkeratosis or visible scaling or both. This chapter deals with the ichthyoses, palmoplantar keratodermas (PPKs) and miscellaneous cornification disorders such as porokeratoses. It is aimed primarily at dermatologists and physician scientists who have to make a clinical diagnosis and provide adequate management for their patients. Therefore a nosology and classification scheme has been chosen that is based on clinicogenetic and morphological features. Clinical diagnoses are then discussed with their molecular pathology. Part of the chapter addresses the management of congenital ichthyoses. Various tables provide an overview on clinical and/or pathophysiologically related groups of diseases. Finally, several cornification disorders are discussed that do not have a genetic basis, but are acquired or are of unknown aetiology (e.g. acquired ichthyoses/PPKs or perforating keratotic disorders).
The disorders of cornification (DOC) are a heterogeneous group of inherited conditions that involve abnormal keratinocyte differentiation resulting in dry, scaling, thickened skin, and variable degrees of associated inflammation. The general goals of therapy for children with DOC are to: (i) preserve function; (ii) maximize the quality of life by improving itch, sleep, and appearance; and (iii) prevent complications such as infection, dehydration, and poor growth. The mechanism of action, appropriate use, and side effects of specific therapies such as emollients, keratolytics, antimicrobials, bath additives, physical treatments, retinoids, retinoic acid, metabolism blocking agents, and targeted therapy are discussed. We then present the therapeutic ladders supported by evidence for selected DOC such as non-syndromic ichthyoses, Netherton syndrome, Sjogren-Larsson syndrome, Darier disease, and palmoplantar keratodermas.
Using the water for treatment purposes is associated hot springs, it can also be realized by bringing, cold mineral water appropriate operating conditions. As a source of cold water, Lake Van water has a mineralization of 20,101 mg / L. It has mixed form consisting of bicarbonate, sulphate, sodium, chloride, potassium components and its ph is 9.3. The main elements making this water different are the abundance of its overall mineral content, high level of bicarbonate and significantly alkaline ph value. Lake Van water beeing balneotherapeutic, has the qualities wihch might be used as a complementary therapy in some diseases either alone or together with other treatment modalities. The availability of this potential is dependent on the eliminatione of important defeciencies such as permanent measures to be taken against this pollutant factors, modern and appropriate facilities in which scientific applications can be carried out and the recruitment of qualified personnel together with proper scientific cadres.
Management of ichthyoses is a complex and continuously dynamic process. Primary treatments of ichthyosis are by means of topical moisturizers and topical medications. Patients and families need to have reasonable and realistic expectations when it comes to topical therapy. Topical medications cannot cure the scaling, but can gradually reduce it and thus improve their condition. No one treatment regimen works for everyone, and the best topical therapy for each patient may be the result of months (or years) of painstaking effort on both the physician's and the patient's behalf. As patients get older and their activities and lifestyles change, so should their topical treatment regimen. Bear in mind that the more complex the skin care regimen and costly the topical treatments, the less likely a patient and their family will be compliant.
The acidic pH of the horny layer, measurable on the skin surface, has long been regarded as a result of exocrine secretion of the skin glands. The ‘acid mantle’ was thought to regulate the bacterial skin flora and to be sensitive primarily to skin cleansing procedures.
In recent years, an increasing number of investigations have been published on the changes in, and constituents and functions of, the pH of the deeper layers of the stratum corneum, as well as on the influence of physiological and pathological factors. A central role for the acidic milieu as a regulating factor in stratum corneum homeostasis is now emerging. This has relevance to the integrity of the barrier function, from normal maturation of the stratum corneum lipids through to desquamation. Changes in the pH and the organic factors influencing it appear to play a role, not only in the pathogenesis, prevention and treatment of irritant contact dermatitis, but also of atopic dermatitis and ichthyosis and in wound healing.
On the basis of these findings, a broader concept, exceeding the superficial ‘acid mantle’ theory, has been formulated.
The acidic pH-value measurable at the skin surface was for a long time regarded as being mainly a result of exocrine secretion of skin glands with the function to regulate the bacterial skin flora as, 'acid mantle' and with relevance primarily to skin cleansing. In recent years, investigations were increasingly published regarding the course, constituents and functions of the pH-value also in deeper horny layers and influences of physiological and pathological factors. More and more a central role of the acidic milieu is delineated as regulating factor for the stratum corneum homeostasis with relevance to the integrity of the barrier function from regular stratum corneum lipid maturation up to desquamation. For the pathogenesis, prevention and treatment of irritant contact dermatitis, atopic dermatitis and ichthyosis as well as for wound healing alterations of pH-value and its organic factors seem to be significant. From this a broadened concept, exceeding the superficial 'acid mantle', is concluded.
Ichthyoses are a group of diseases with clinical and genetic heterogeneity which belong to the genetic disorders of skin keratinization. In common with the genodermatoses, the ichthyoses are regarded as incurable. From the patient's point of view, though, this therapeutic nihilism is unjustified and unhelpful. Several treatment options exist which, while unable to offer a cure, are able to improve the skin condition considerably. We present a case series of 692 patients treated over a 20 year period, and discuss therapies which have proved helpful in improving health related quality of life in this patient group, many of them little known.
Report covers laboratory study and clinical trials on a series of chemical formulations to find means of chemically binding agents to skin elements or of permanent absorption to provide long term (7 days) protection from sunburn regardless of heavy sweating or washing actions. Results are reported in detail and tabulated. Two preparations were developed which were effective for long term exposure (4 hr) after single application and were resistant to washing action. Preparations did not interfere with tanning action and were cosmetically acceptable. Two were very effective under conditions of bright sun in dry climate or high elevation and snow environments. Stable binding to skin providing 7-day or longer protection was not achieved. (Author)
Solar urticaria is a relatively rare immunoglobulin E-mediated photodermatosis that is caused by specific, yet diverse wavelengths of light. The history, epidemiology, clinical manifestations, histology, etiology/pathogenesis, differential diagnosis, treatment, course, and prognosis of solar urticaria are reviewed herein. Learning objective: After completing this learning activity, participants should be able to describe the clinical manifestations of solar urticaria, summarize the proposed mechanisms of pathogenesis, and discuss the management options of solar urticaria.
30 patients with multiple types of sunlight sensitivity were treated successfully with DHA/lawsone sunscreen. This sunscreen was able to protect all patients even though their photosensitivities were in different parts of the ultraviolet and visible spectrum. About 80% of the patients experienced sufficient protection during the summer months to lead a virtually normal life-style while participating in all kinds of outdoor activities.
The acidic pH of the horny layer, measurable on the skin surface, has long been regarded as a result of exocrine secretion of the skin glands. The 'acid mantle' was thought to regulate the bacterial skin flora and to be sensitive primarily to skin cleansing procedures. In recent years, an increasing number of investigations have been published on the changes in, and constituents and functions of, the pH of the deeper layers of the stratum corneum, as well as on the influence of physiological and pathological factors. A central role for the acidic milieu as a regulating factor in stratum corneum homeostasis is now emerging. This has relevance to the integrity of the barrier function, from normal maturation of the stratum corneum lipids through to desquamation. Changes in the pH and the organic factors influencing it appear to play a role, not only in the pathogenesis, prevention and treatment of irritant contact dermatitis, but also of atopic dermatitis and ichthyosis and in wound healing. On the basis of these findings, a broader concept, exceeding the superficial 'acid mantle' theory, has been formulated.
Both exposure of stratum corneum to neutral pH buffers and blockade of acidification mechanisms disturb cutaneous permeability barrier homeostasis and stratum corneum integrity/cohesion, but these approaches all introduce potentially confounding variables. To study the consequences of stratum corneum neutralization, independent of hydration, we applied two chemically unrelated superbases, 1,1,3,3-tetramethylguanidine or 1,8-diazabicyclo [5,4,0] undec-7-ene, in propylene glycol:ethanol (7:3) to hairless mouse skin and assessed whether discrete pH changes alone regulate cutaneous permeability barrier function and stratum corneum integrity/cohesion, as well as the responsible mechanisms. Both 1,1,3,3-tetramethylguanidine and 1,8-diazabicyclo [5,4,0] undec-7-ene applications increased skin surface pH in parallel with abnormalities in both barrier homeostasis and stratum corneum integrity/cohesion. The latter was attributable to rapid activation (<20 min) of serine proteases, assessed by in situ zymography, followed by serine-protease-mediated degradation of corneodesmosomes. Western blotting revealed degradation of desmoglein 1, a key corneodesmosome structural protein, in parallel with loss of corneodesmosomes. Coapplication of serine protease inhibitors with the superbase normalized stratum corneum integrity/cohesion. The superbases also delayed permeability barrier recovery, attributable to decreased beta-glucocerebrosidase activity, assessed zymographically, resulting in a lipid-processing defect on electron microscopy. These studies demonstrate unequivocally that stratum corneum neutralization alone provokes stratum corneum functional abnormalities, including aberrant permeability barrier homeostasis and decreased stratum corneum integrity/cohesion, as well as the mechanisms responsible for these abnormalities.
Sunless tanning preparations have been used for more than 50 years and are still very popular because they provide temporary pigmentation resembling an ultraviolet-induced tan. The pigment is the product of reactions between dihydroxyacetone (DHA) and amino acids in the stratum corneum.
To understand the factors that influence the reactions of DHA with amino acids in the stratum corneum with the ultimate goal of producing pigmentation with greater photoprotection.
The influence of hydration and/or oxygen on the development of DHA-induced pigment was assessed in vivo using an occlusive dressing and ex vitro on human epidermal preparations. Two spectroscopic techniques, diffuse reflectance and fluorescence emission, were used to monitor the extent of pigment development. The optimal relative humidity for DHA-induced pigmentation was assessed on the epidermal preparations. The formation of products from reactions between DHA and nine amino acids was studied in solutions buffered at pH 5 and 7.
Development of DHA-induced pigmentation was inhibited by a 24-h occlusive dressing but appeared after its removal, indicating that DHA was still present. High hydration but not the absence of oxygen inhibited coloration of occluded skin. The extent of pigmentation did not vary in a simple manner with hydration, as pigment formation was positively correlated with humidity from 0 to 75% but negatively correlated from 75 to 100%. Lysine, glycine and histidine reacted most rapidly with DHA, with reaction rates greater at pH 7 than at pH 5. The products absorbed with maxima at wavelengths up to 340 nm.
These results indicate that extent of hydration, pH and availability of certain amino acids influence the development of DHA-induced pigmentation in the stratum corneum and suggest that manipulation of these factors might produce pigmentation with greater photoprotection.
Serine proteases belonging to the kallikrein group may play a central role in desquamation. We have identified human kallikreins 5, 7, and 14 (hK5, hK7, hK14) in catalytically active form in stratum corneum. All three enzymes are produced as inactive precursors. In this work, we prepared recombinant enzymes and enzyme precursors and characterized the catalytic properties of hK5 and hK14. With peptide substrates hK5 and hK14 both showed trypsin-like specificity and alkaline pH-optima. For the substrates tested, hK14 was superior to hK5 as regards maximum catalytic rate as well as catalytic efficiency. hK5, but not hK14, could activate pro-hK7 in a reaction which was optimal at pH 5-7. hK5 could activate its own precursor as well as pro-hK14. This was in contrast to hK14, which could activate pro-hK5 but not its own precursor. The activation of pro-hK5 either by auto-activation or by hK14 occurred at maximum rate at neutral or weakly alkaline pH, whereas activation of pro-hK14 by hK5 was optimal at pH 6-7. We conclude that the enzymes studied may be part of a protease cascade in the stratum corneum, and that the observed pH effects may have physiological relevance.
During seven months of a clinical trial in spring, summer, and fall, 30 UVA/B/Soret band-photosensitive patients used sequential topical applications of dihydroxyacetone (DHA) followed by naphthoquinone only at bedtime and received excellent photoprotection without a single therapeutic failure or loss of any patient to follow-up. Eighteen of the 30 patients extended the limits of their photoprotection repeatedly over a seven-month period to tolerate without sunburns six to eight hours of midday sunlight under all kinds of occupational and recreational environmental conditions. Previously, the use of 3% DHA topically in earlier studies gave only a sun protection factor (SPF) of 3. In this reanalysis of the original notes of a previous clinical study of the melanoidins produced by DHA followed by naphthoquinone in the keratin layers of the epidermis of minimally pigmented Caucasian photosensitive patients, it is determined that these patients received a minimal UVB photoprotection of SPF 18 or more. This represents at least a sixfold amplification of the UVB photoprotective effect over the use of only dihydroxyacetone in the Maillard reaction.
Treatise on diseases of the skin. Philadelphia and London: W.B. Saunders
- Hw Stelwagon
Stelwagon HW. Treatise on diseases of the skin. Philadelphia and London: W.B. Saunders; 1902.
Chemical binding of protective agents to the stratum corneum. Contract No. DA 49-092-ARO-85, Depart-ment of the US Army, Army Research Office
- Fitzpatrick Tb
- Pathak
- Ma
Fitzpatrick TB, Pathak MA. Chemical binding of protective agents to the stratum corneum. Contract No. DA 49-092-ARO-85, Depart-ment of the US Army, Army Research Office. Arlington, VA: 1968.
The acid mantle of the skin
- Schade
Schade H, Marchionini A. The acid mantle of the skin [in
German].