Severity of papular urticaria in children is associated with specific IgG4 anti-salivary gland antigens from Aedes aegypti.

Summary: Background. Papular Urticaria (PU) is a cutaneous hypersensitivity disorder triggered by hematophagous arthropod bites. Despite being a common condition, especially in tropical environments, many knowledge gaps are observed for this disease. The main objective of this study was to investigate the patterns of humoral immune response to mosquito antigens in children with PU and establish a correlation between this response and the severity of clinical symptoms. Methods. An analytical cross-sectional observational study was carried out. Clinical and sociodemographic data and children's blood samples were collected to measure the specific antibodies from: 1. A. aegypti salivary gland antigens; 2. A. aegypti whole body antigens (both produced in the laboratory of the Center for Health Sciences at the Federal University of Rio de Janeiro). A PU severity score based on clinical data is proposed to correlate disease severity with antibody reactivity signatures. Results. According to the clinical data, 58.9% of children received high severity scores. A significant statistical correlation was found between patients with high PU severity score and the development of symptoms before the age of two (p = 0.0326) and high IgG4 anti-salivary gland antigens concentration (p less than 0.05). Conclusion. It is suggested that PU severity in children is associated with a high concentration of IgG4 anti-salivary gland antigens from Aedes aegypti. Further studies are recommended to deepen the understanding of the mechanisms involved.

Bed Bug Infestation: An Updated Review.

In the past decade, there has been a global resurgence of bed bug infestations, especially in developed countries. Proper awareness and identification of bed bug infestations are essential to guide treatment and eradication. The purpose of this article is to familiarize physicians with bed bug bites so that they can effectively diagnose, treat, and address questions about bed bug bites and infestations. Bed bug bites are often painless. Typical reactions include pruritic, erythematous maculopapules occurring in clusters or in a linear or curvilinear distribution in exposed areas of the body. A small red punctum may be visualized at the center of the bite mark. Lesions that appear three in a row and papules on the upper eyelid associated with erythema and edema are highly suggestive of bites from bed bugs. Exaggerated local reactions such as vesicles, urticarial wheals, urticarial perilesional plaques, diffuse urticaria, bullae, and nodules may occur in previously sensitized individuals. Reactions to bed bug bites are self-limited. As such, treatment is mainly symptomatic. Topical pramoxine and oral antihistamines can be used to alleviate pruritus. Topical corticosteroids can be used for significant eruptions to control inflammation and pruritus, and to hasten resolution of the lesions. Integrated pest management, an approach for the eradication of bed bugs, includes monitoring devices (active monitors include the use of heat or carbon dioxide attractants and passive monitors include the use of sticky pads for trapping), and judicious use of nonchemical and chemical treatments known to be effective. Nonchemical interventions include keeping affected areas clean and free of clutter, vacuuming, washing linens with hot water, caulking wall holes and cracks where bugs can hide, proper disposal of highly infested items, and placement of bed bug traps/interceptors at the base of beds and furniture. Chemical interventions involve the use of insecticides such as synthetic pyrethroids, silicates, insect growth disruptors, carbamates, organophosphates, neonicotinoids, diethyl-meta-toluamide, chlorfenapyr, fipronil and plant essential oils. Insecticides should be used with caution to prevent over-exposure and toxicity (in particular, cardiovascular and neurologic toxicity), especially if there are young children around. It is important to note that multiple mechanisms of insecticide resistance exist and as such, chemical treatment should only be undertaken by trained professionals who understand the current literature on resistance. Both nonchemical and chemical technologies should be combined for optimal results. Bed bug infestations may cause diverse dermal reactions, stigmatization, poor self-esteem, emotional stress, anxiety, significant adverse effect on quality of life, and substantial socioeconomic burden to society. As such, their rapid detection and eradication are of paramount importance. Consultation with a professional exterminator is recommended to fully eradicate an infestation.

Pilot study: specific immunotherapy in patients with Papular urticaria by Cimex lectularius.

Summary: Background. Papular urticaria is a chronic allergic reaction induced by insect bites. In México the most common causative arthropods reported are bed bugs, fleas and mosquitoes. Approximately 70% of people who are bitten by Cimex lectularius experience hypersensitive reactions, papular urticaria, extensive erythema, urticaria, and even anaphylaxis has been reported, pruritus is the major complaint, impairing quality of life and sleep. Immunotherapy has been used in mosquito bite papular urticaria resulting in improvement of skin lesions and possibly protecting against reactions to subsequent exposures to mosquitoes. Methods. Children, 4-10 years of age, with recurrent papular urticaria due to bedbugs not responsive to multiple treatments were included. An initial allergy assessment included clinical history, skin prick test (SPT), and specific IgE sensitisation was performed to confirmed bedbug sensitization. Twenty children were randomized to receive subcutaneous specific immunotherapy (SSI) with whole body bed bug extract or conventional treatment. The treatment was carried out over twelve months and the response was assessed using the Dermatology Quality of Life Index (DLQ), the immunotherapy satisfaction questionnaire (ESPIA questionnaire) and the 12-Item Pruritus Severity Scale (12-IPSS). The results from both the treated and control groups were compared. Results. The twenty patients were randomized, 12 to receive immunotherapy and 8 to receive conventional treatment for 12 months. Quality of life improved with a reduction in the DLQI score of 19.83 in the immunotherapy group versus 9 in the conventional treatment group (p = 0.03). Itch improved with a reduction in the 12-IPSS of 16.5 in the immunotherapy group versus 9.63 in the conventional treatment group (p = 0.02). After twelve months of treatment, all 12 patients who received immunotherapy, reported a decrease of persistent cutaneous lesions but the 8 on conventional treatment did not. A mean score of 95.75 (SD 3.3) was recorded for satisfaction with immunotherapy. Conclusions. Patients with papular urticaria by Cimex lectularius receiving allergen immunotherapy for 1 year showed a significant improvement compared with baseline and patients receiving conventional treatment regarding skin lesions, quality of life impairment, intensity of pruritus and satisfaction with immunotherapy.

Prevalence of atopic diseases in children with papular urticaria.

BACKGROUND: Papular urticaria is a hypersensitivity reaction characterized by chronic and recurrent papular erythema. It occurs as a result of the bites of mosquitoes, fleas, bed bugs, and other insects; and it is generally seen in children. This study examines the prevalence of atopic diseases in patients with papular urticaria. METHODS: The medical records of 130 pediatric patients with the diagnosis of papular urticaria between August 2017 and August 2019, whose disease progression was followed in two tertiary care centers, were reviewed retrospectively. The patients were divided into two groups: under 5 and above 5 years old. The prevalence of the atopic disease in children with papular urticaria was compared with those in age-matched controls without papular urticaria. RESULTS: The study included 130 patients who were diagnosed with papular urticaria (64 males, 66 females, median age: 60 months). The prevalences of atopic disease, recurrent wheezing, and atopic dermatitis were higher in the group under 5 years old with papular urticaria than in the same-age control group (p=0.001, 0.002, and 0.001, respectively). The prevalences of atopic disease, asthma, allergic rhinitis, and atopic dermatitis were higher in the group above 5 years old with papular urticaria than in the same-age control group (p=0.001, 0.001, 0.001, and 0.007, respectively). CONCLUSIONS: Many children with papular urticaria are atopic children. These patients should be assessed not only in terms of papular urticaria but also in terms of comorbid atopic diseases.

Prevalence of skin diseases in children 1 to 6 years old in the city of Bogota, Colombia.

BACKGROUND: Skin diseases represent an important part of the morbidity among children and are possibly influenced by geographic, racial, social, cultural, and economic factors. Despite being so frequent around the world, skin diseases have not been important in developing strategies in public health. AIM: The purpose of this study was to evaluate the prevalence of skin diseases among the student population between 1 and 6 years of age in Bogotá, Colombia between March 2009 and June 2011. MATERIALS AND METHODS: This cross-sectional study was performed across a probabilistic, stratified, randomized sampling by proportional assignment (based on locality and type of institution) and was developed in schools in Bogotá, Colombia. RESULTS: A total of 2437 children between 1 and 6 years of age were examined, and 42.8% (1035) presented a dermatologic disease. Papular urticaria was the most frequent (62.9%) (IC: 58.4%; 67.1%), followed by dermatitis/eczema (13.0%) (IC: 10.8%; 15.4%), and infectious diseases (12.3%) (IC: 9.7%; 15.3%). CONCLUSION: The research demonstrates a high prevalence of papular urticaria as a result of flea and mosquito bites and infectious diseases of the skin in the studied population. The dermatologic diseases found are easy to diagnose, respond to the proper treatment, and are preventable. However, the fact that many of the examined children likely had not visited the doctor for the detected pathology could indicate the lack of access to health services affecting this population.

Cellular and Humoral Responses to Cte f 2, a Cat Flea Allergen, in Children with Papular Urticaria.

BACKGROUND: Papular urticaria (PU) is a common insect bite skin hypersensitivity in tropical countries. In order to gain insight into its causal allergens, we aimed to evaluate cellular and humoral immune responses to the recombinant salivary antigen Cte f 2 from the cat flea Ctenocephalides felis. METHOD: Sixty patients with PU and 27 healthy controls were included in this study. Specific IgE, IgG, IgG1, and IgG4 against Cte f 2 and C. felis extract were determined by ELISA. The T-cell response was analyzed using a carboxyfluorescein succinimidyl ester (CFSE)-based dilution assay and Th1/Th2/Th17 cytokine measurements. In addition, a proteomic analysis of IgG and IgE reactive spots of C. felis extract was performed. RESULTS: The frequency of IgE sensitization to Cte f 2 was similar between patients (36.7%) and controls (40.7%). The specific IgE, IgG1, and IgG4 responses to Cte f 2 and C. felis extract were not significantly different between patients and controls. Among the 3 conditions (i.e., Cte f 2, C. felis extract, and only medium) Cte f 2 was the strongest inducer of CD3+CD4+ proliferation in the patients; however, the mean response was not significantly different from those in controls (Cte f 2: 4.5 vs. 2.5%; p = 0.46). No salivary proteins were identified in C. felis, and most of the spots were identified as muscle-skeletal components (tropomyosin, actin, myosin, and ankirin). CONCLUSIONS: Cte f 2 induces IgE and IgG production as well as T-cell proliferation in children living in a geographical area where PU induced by a flea bite is common. The use of C. felis extract is not recommended for the study of bite-induced hypersensitivity disease since salivary antigens are not well represented.

Prevalence of papular urticaria caused by flea bites and associated factors in children 1-6 years of age in Bogotá, D.C.

BACKGROUND: Papular urticaria is a chronic inflammatory disease caused by exposure to arthropod bites. The disease has been reported in children attending medical centers, but the causes as the risk factors associated with the disease have not been established. The objective of this study was to determine the prevalence of papular urticaria caused by flea bite and identify the risk factors in children between 1 to 6 years of age in Bogotá D.C, between March 2009 and June 2011. METHODS: A cross-sectional, two-stage, clustered study using random probability sampling and stratified with proportional allocation was carried out in children (1-6 years of age) in educational institutions in Bogotá D.C. to determine the prevalence of the disease. Children underwent a dermatological examination by general practitioners with a previous training. Furthermore, digital photographs of skin lesions were taken for further confirmation of the diagnosis by dermatologists. A structured survey was completed by the parents or caregivers, and it was evaluated using an unconditional logistic regression to identify factors associated with the disease. RESULTS: A total of 2437 children were included in the study. The prevalence of papular urticaria caused by flea bite in this population was 20.3% (CI 95%: 18.2 to 22.5%). The major risk factors associated with the disease were the presence of fleas in households (OR 1.74, CI 95%: 1.35 to 2.25), using mattresses without springs (OR 1.73, CI 95%: 1.20 to 2.50), the use of daily public transportation to carry the children to the educational institutions (OR 1.76, CI 95%: 1.07 to 2.89), having a soil/earth floor in the main bedroom (OR 6.81, CI 95%:1.16-39.96), and having siblings with a history of atopic dermatitis (OR 1.76 CI 95%: 1.07-2.89). CONCLUSIONS: A high prevalence of papular urticaria caused by flea bite was found in Bogotá D.C. The main factors associated with the disease might be modified with the implementation of prevention, control strategies in housing, educational institutions, and public transportation.

Particularities of allergy in the Tropics.

Allergic diseases are distributed worldwide and their risk factors and triggers vary according to geographical and socioeconomic conditions. Allergies are frequent in the Tropics but aspects of their prevalence, natural history, risk factors, sensitizers and triggers are not well defined and some are expected to be different from those in temperate zone countries. The aim of this review is to investigate if allergic diseases in the Tropics have particularities that deserve special attention for research and clinical practice. Such information will help to form a better understanding of the pathogenesis, diagnosis and management of allergic diseases in the Tropics. As expected, we found particularities in the Tropics that merit further study because they strongly affect the natural history of common allergic diseases; most of them related to climate conditions that favor permanent exposure to mite allergens, helminth infections and stinging insects. In addition, we detected several unmet needs in important areas which should be investigated and solved by collaborative efforts led by the emergent research groups on allergy from tropical countries.

Epidemiological study of insect bite reactions from central India.

INTRODUCTION: The physical effects of the arthropod bites on human skin receive less attention, especially in the rural areas where the per capita income is less. Ours is a rural-based hospital, the vicinity having more of plants, trees, and forests; we undertook the study to find out the relation of insect bite dermatitis in a rural area. MATERIALS AND METHODS: The study was carried out in the Dermatology outpatient department of our institute on 100 subjects of insect bite dermatitis who were questioned retrospectively about the sequence of events besides their environmental and living conditions. They were examined thoroughly and the relevant clinical findings were noted, also taking into account the prior treatment taken by them, if any. RESULTS AND CONCLUSIONS: It was found that insect bite dermatitis has no age or gender preponderance, and the protective factors for the same are use of full sleeve clothes and keeping the doors and windows closed at night. On the contrary, the risk factors are residence in areas of heavy insect infestation, use of perfumes and colognes, warm weather in spring and summer and the lack of protective measures. However, there was no direct association of atopy with increased risk of developing insect bite dermatitis.

Incidence and care of environmental dermatoses in the high-altitude region of ladakh, India.

BACKGROUND: Low humidity, high-velocity wind, excessive ultraviolet (UV) exposure, and extreme cold temperature are the main causes of various types of environmental dermatoses in high altitudes. MATERIALS AND METHODS: A retrospective study was carried out in patients visiting the lone dermatology department in Ladakh between July 2009 and June 2010. The aim was to identify the common environmental dermatoses in high altitudes so that they can be treated easily or prevented. The patients were divided into three demographic groups, namely, lowlanders, Ladakhis (native highlanders), and tourists. Data was analyzed in a tabulated fashion. RESULTS: A total of 1,567 patients with skin ailments were seen, of whom 965 were lowlanders, 512 native Ladakhis, and 90 were tourists. The skin disorders due to UV rays, dry skin, and papular urticaria were common among all groups. The frequency of melasma (n = 42; 49.4%), chronic actinic dermatitis (CAD) (n = 18; 81.81% of total CAD cases), and actinic cheilitis (n = 3; 100%) was much higher among the native Ladakhis. The frequency of cold-related injuries was much lesser among Ladakhis (n = 1; 1.19%) than lowlanders (n = 70; 83.33%) and tourists (n = 13; 15.47%) (P < 0.05). CONCLUSION: Dryness of skin, tanning, acute or chronic sunburn, polymorphic light reaction, CAD, insect bite reactions, chilblain, and frostbite are common environmental dermatoses of high altitudes. Avoidance of frequent application of soap, application of adequate and suitable emollient, use of effective sunscreen, and wearing of protective clothing are important guidelines for skin care in this region.

Asociación de polimorfismos de la región promotora del gen de la interleucina 10 con la urticaria papular por picadura de pulga / Association of Interleukin 10 (IL-10) gene promoter region polymorphisms with flea bite papular urticaria

Objetivos. Establecer si los polimorfismos en la región promotora del gen de la IL-10 localizados en las posiciones -819 y -592 están asociados con la urticaria papular causada por la picadura de pulga, en pacientes pediátricos que asistieron a consulta de alergia o de dermatología a la Fundación Santa Fe de Bogotá, Colombia. Métodos. La frecuencia de estos dos polimorfismos en el ADN fue analizada en 25 niños con urticaria papular y 22 controles por medio de PCR (Polymerase Chain Reaction) y RFLP (Restriction Fragment Length Polymorphisms). Resultados. No hubo diferencias significativas entre las frecuencias alélicas y genotípicas de cada polimorfismo individual o SNP (-819 o -592) entre pacientes y controles (p=0,21, OR=1,87, IC95% 0,79-4,40) cuando fueron calculados por la prueba exacta de Fisher. Conclusiones. Aunque en este trabajo preliminar no se encontró asociación de los polimorfismos reportados en otras poblaciones con la enfermedad alérgica, hay una tendencia en nuestros experimentos a encontrar un mayor número de haplotipos AT en pacientes que en controles Los resultados publicados por nuestro grupo de investigación, en cuanto a que la secreción de IL-10 in vitro se encuentra disminuida en pacientes con urticaria papular y no en controles sanos, indicar ían que la expresión genética de esta citocina estaría alterada en pacientes y, por consiguiente, esta condición estaría exacerbando la enfermedad. Los niveles disminuidos de esta citocina reguladora permitirían el desarrollo de condiciones hiperinmunes, como la alergia y la autoinmunidad...

Objectives: In this study we aimed to establish whether IL-10 promoter region genetic polymorphisms in positions -819 and -592 were associated with papular urticaria caused by flea bite in pediatric patients from the Fundación Santa Fe de Bogotá, Colombia.Methods: The frequency of these DNA polymorphisms was analyzed in 25 infants suffering papular urticaria and 22 healthy controls, after amplification of their corresponding DNA through polymerase chain reaction (PCR) and further analysis of resulting restriction fragment length polymorphisms (RFLP). Results: We found no significant differences in allelic and genotypic frequencies of either -819 or -592 SNPs between patients and healthy controls (p=0.21, OR=1.87, 95% IC=0.79-4.40). Conclusions: Although we did not find in this preliminary study a genetic association between papular urticaria and previously reported allergyassociated SNPs such as -819 and -592, we found higher numbers of allergy-associated AT haplotypes in patients than in controls. Previously published results from our group showed in vitro a diminished IL-10 secretion in patients and not in healthy controls. This finding, together with our present results, would indicate that the genetic expression of this cytokine could be altered in patients and that this condition could determine the exacerbation of papular urticaria. Low levels of this cytokine would allow for the development of hyperimmune conditions such as allergy and autoimmunity...

The etiology of papular urticaria: a systematic review / 中华皮肤科杂志

Objective To investigate the etiology of papular urticaria: is it caused only by arthropod-like insects-bite allergy, or by multiple factors such as food allergy, disturbance of gastrointestinal function and infection? Methods We searched, by computer and manually, the foreign and domestic literature related to the etiology of papular urticaria published since 1950s, and according to the methods of evidence-based medicine, systematically evaluated the evidence supporting either the insect-bite theory or the multiple factor theory. Results Twenty-nine articles ( 22 English and 7 Chinese ) supported the theory of hypersensitivity to bites from certain insects such as mosquitoes, gnats, fleas, mites, bedbugs etc. Two articles in Chinese mentioned the possibilities other than insect-bite, but the reliability was unconvincing, because the authors did not present the source of data or statistical methods used in the articles. The evidence from epidemiology, histopathology, laboratory and clinical researches all supported the insects-bite theory. No proven evidence was found supporting other aetiological hypotheses. Conclusion Our results suggest that papular urticaria is caused only by the allergy to stings or bites of arthropods, and other hypotheses still lack convincing evidence.