Elevated Total Serum IgE Levels Research Articles

Dendritic cells under allergic condition enhance the activation of pruritogen-responsive neurons via inducing itch receptors in a co-culture study

BackgroundItch sensitization has been reported in patients with chronic allergic skin diseases and observed in a mouse model of allergic contact dermatitis (ACD). There is evidence suggesting that neuroimmune interactions may contribute to itch sensitization, as an increase in dendritic cells (DCs) within ganglia has been observed during allergic conditions. However, how DCs interact with sensory neurons in ganglia during allergic conditions is still not known. This study aims to investigate the role of DCs in dorsal root ganglion (DRG) under ACD conditions, specifically focusing on itch sensitization within the DRG. The tolylene-2,4-diisocyanate (TDI) mouse model for ACD and the co-culture model of DCs and DRG neurons was employed in this study.ResultsWe successfully induced ACD by TDI, as evidenced by the development of edema, elevated total serum IgE levels, and an observed itch reaction in TDI-sensitized mice. Calcium imaging and RT-qPCR analysis revealed that TDI-sensitized mice exhibited signs of peripheral sensitization, including a higher percentage of neurons responding to pruritogens and increased activation and expression of itch receptors in excised DRG of TDI-sensitized mice. Immunofluorescence and flow cytometric analysis displayed an increase of MHCII+ cells, which serves as a marker for DCs, within DRG during ACD. The co-culture study revealed that when DRG neurons were cultured with DCs, there was an increase in the number of neurons responsive to pruritogens and activation of itch receptors such as TRPA1, TRPV1, H1R, and TRPV4. In addition, the immunofluorescence and RT-qPCR study confirmed an upregulation of TRPV4.ConclusionsOur findings indicate that there is an increase of MHCII+ cells and itch peripheral sensitization in DRG under TDI-induced ACD condition. It has been found that MHCII+ cells in DRG might contribute to the itch peripheral sensitization by activating itch receptors, as shown through co-culture studies between DRG neurons and DCs. Further studies are required to identify the specific mediator(s) responsible for peripheral sensitization induced by activated DCs.

CORRELATION BETWEEN TOTAL SERUM IgE LEVELS AND SOME CHARACTERISTICS IN VIETNAMESE PEMPHIGOID PATIENTS

Objectives: To determine the correlation between total serum IgE levels and some clinical and subclinical characteristics in pemphigoid patients.Methods: A cross-sectional study on 42 pemphigoid patients, all of which were newly diagnosed. Information was collected from patient interviews and medical records. Total serum IgE levels were determined using a total IgE ELISA following the manufacturer’s instructions. Eosinophil counts were analyzed on the same day when serum samples were taken. For IgE DIF staining of perilesional skin, IgE Goat anti-Human, FITC was used, incubation was performed overnight at 4oC.Results: Among 42 pemphigoid patients, the average age was 73.2 ± 15.5 years old. 60% of pemphigoid patients had elevated total serum IgE levels, the mean value was 121.6 ± 101.8 UI/mL. Total serum IgE levels were significantly correlated with eosinophil counts (r = 0.61; p < 0.05) and the BPDAI urticaria/erythema (U/E) score (r = 0.50; p < 0.05). However, total circulating IgE levels were not significantly associated with total BPDAI score (p > 0.05). DIF IgE staining on perilesional skin of pemphigoid patients had a positive rate of 14.3%.Conclusion: Total serum IgE values correlated with some clinical and subclinical characteristics in pemphigoid patients. IgE autoantibodies were present in the skin of pemphigoid patients, supporting the hypothesis that IgE potentially modulates pruritus associated with pemphigoid.

An Allergic Risk Factor Analysis of Extraordinary Daytime Only Urinary Frequency in Children.

ObjectiveThis study aims to investigate the risk factors of extraordinary daytime only urinary frequency (EDOUF) and propose a form of clinical treatment.MethodsCorrelation and binary logistic regression analyses were carried out on the medical records of children with EDOUF, including their history of eczema, urticaria, allergic rhinitis or allergic cough, and pruritus (eye rubbing, etc.).ResultsA total of 266 children with EDOUF, 127 boys and 139 girls, were enrolled in the present study; their average age was 5.60 ± 2.04 years. Binary logistic regression analysis revealed that the risk factors of EDOUF in children were eczema (odds ratio [OR] = 8.393), allergic rhinitis or allergic cough (OR = 4.459), pruritus (eye rubbing, etc.; OR = 3.879), and elevated total serum IgE level (OR = 7.927). The efficacy rate of oral administration of antihistamine (desloratadine) was 89.1%.ConclusionSystemic or local allergic conditions, such as eczema, allergic rhinitis or allergic cough, and pruritus (including eye rubbing), and elevated total serum IgE level, are risk factors for the occurrence of EDOUF in children. The oral administration of antihistamine (desloratadine) can alleviate the symptoms.

ORMDL3/GSDMB genotype as a risk factor for early-onset adult asthma is linked to total serum IgE levels but not to allergic sensitization

BackgroundAn orosomucoid-like 3 (ORMDL3)/gasdermin B (GSDMB) gene locus on chromosome 17q is consistently associated with childhood-onset asthma, which is highly atopic. As some evidence suggests the relationship between asthma and allergic sensitization reflects asthma patient susceptibility to augmented IgE responses driven by common environmental allergens rather than an increased asthma risk after allergen exposure, we aimed to determine any relationships between this locus region and childhood-onset adult asthma with regard to serum total IgE levels or allergic sensitization. MethodsWe conducted a case–control association study using three independent Japanese populations (3869 total adults) and analyzed the ORs for association of rs7216389, an expression quantitative trait locus for ORMDL3/GSDMB, with adult asthma according to onset age. Additionally, associations between the rs7216389 genotype and total serum IgE levels or allergic sensitization was examined. ResultsRs7216389 was associated with both childhood-onset adult asthma (OR for asthmatic patients afflicted at the age of 10 years or younger = 1.61, p = 0.00021) and asthmatic patients with higher levels of total serum IgE (OR for asthmatic patients with IgE ≥1000IU/mL = 1.55, p = 0.0033). In both healthy controls and in the combined healthy and asthmatic individuals, rs7216389 was correlated with increased total serum IgE levels (p < 0.0005), but not allergic sensitization (p > 0.1). ConclusionsORMDL3/GSDMB is an important susceptibility gene for childhood-onset adult asthma in Japanese populations and this association is linked to elevated total serum IgE levels but not to allergic sensitization.

Estimation of IgE level and Rh factor in patients with atopic dermatitis

Atopic dermatitis (AD), also called atopic eczema, is a common chronic or recurrent inflammatory skin disease and affects 15–20% of children and 1–3% of adults worldwide; IgE is likely to be of more relevance in pediatric disease than in adult disease, in order to detect the incidence of AD and its association with elevated total serum IgE level, 68 people were involved in the current study, their ages were (1-45) years and from both genders fifty of them was with atopic dermatitis and the other healthy eighteen were considered as control groups. They are all subjected to the estimation of total serum IgE level by using Nephelometry methodology technique in the central health laboratory and Hilla Teaching Hospital the period Nov. 2017 to Feb. 201in Babylon Governorate. A significant increase in the level of IgE in AD patients was detected in all age groups in comparison with the control group. The results also showed that patients of blood group (o+) are the most frequent by percent (28%) followed by B+, AB+, A+ and AB¯ with percent reached (24, 20, 14and 4%) respectively. Furthermore, there is a genetic tendency in the frequency of onset of AD as 10% in both parents and (30&amp; 24%) in mothers and fathers respectively while 36% of the disease does not appear in their families. Results also showed a significant increase in the age groups (31-45) years in comparison with (1-15) and (16-30) years. The disease also rises in males compared with females. A significant increase in IgE for patients with Atopic Dermatitis

Immunoadsorption in dermatology

Autoimmmune bullous diseases are mediated by pathogenetically relevant autoantibodies against components of the epidermis and/or superficial mucous membranes (in pemphigus) and structural proteins of the dermal-epidermal junction (in pemphigoid diseases). Using immunoadsorption (IA), an already well-established procedure in cardiac and rheumatic disorders, antibodies can be removed from the plasma. At present, most data on the adjuvant use of IA in dermatology are derived from patients with severe and/or refractory pemphigus vulgaris or pemphigus foliaceus and also from patients with pemphigoid diseases. Additionally, in the last few years different protocols for IA in patients with severe atopic dermatitis and elevated total serum IgE levels have been published. While panimmunoglobulin adsorbers are mainly used in dermatology, an IgE-specific adsorber has been used in some patients with atopic dermatitis and in the future, antigen-specific adsorbers are to be expected that will enable the specific reduction of autoantibodies.

Immunoglobulin E and bullous pemphigoid.

Clinical features and histological findings in bullous pemphigoid (BP) suggest a Th2-oriented inflammatory reaction, especially in the early stages of the disease. Elevated total serum IgE levels, blood eosinophilia, and elevated serum levels of different soluble inflammatory Th2 response mediators have been described in large cohorts of patients with classic clear-cut BP manifestations. Direct immunofluorescence, indirect immunofluorescence, and anti-BP230 and anti-BP180 IgE ELISA testing show self-reactive IgE autoantibodies in a consistent number of BP patients. Both IgE autoantibodies and a Th2-oriented immune response may play a role in the initial phases of BP and atypical cases of BP, such as severe erythematous and urticarial forms of BP, as well as blister formation. Two recently reported experimental murine models employing IgE autoantibodies against BP180 have been reported and the successful treatment of bullous pemphigoid with the anti-IgE antibody, omalizumab, supports the roles played by IgE autoantibodies in BP pathogenesis.

Susceptibility to allergy in adoptive children: a cross-sectional study at \u201cBambino Ges\xf9 Children\u2019s Hospital\u201d

BackgroundPrevalence of allergy has steeply increased during the past few decades, particularly in high-income countries. The development of atopy could present different characteristics in internationally adopted children with regard to incidence, specific patterns of allergies and timing of occurrence. We aimed to investigate the occurrence of allergic diseases among adopted children in Italy.MethodsWe collected demographic information, preadoption immunization data, infectious diseases screening results, immunological status, and performed hematological and biochemical tests according to a standardized protocol in 108 adopted children.ResultsAt initial visit (mean age was 5.7 ± 3.2 years), 48 children displayed elevated total serum IgE levels with a prevalence of 56.5% (95%CI: 0.45; 0.67). The prevalences of children screened positive for one or more food allergens and inhalants were 30.1% (95%CI: 19.9%; 42.0%) and 34.3% (95%CI: 23.3%; 46.6%) respectively, only 9 children exhibited abnormal absolute eosinophil counts, 23 (21.3%) had a parasitic infection and 60 (55.6%) had received at least one dose of vaccine.ConclusionsChildren without medical records or with a past medical history suggestive of atopy should perform a thorough allergy evaluation at the time of adoption. Our study offers also a glimpse at the vaccination status and immune-allergic profiles of recent migrant children in Italy.

Allergic Bronchopulmonary Aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) is an immunologic bronchopulmonary inflammation due to an immune response of the lower respiratory tract against Aspergillus fumigatus. The major clinical features of ABPA include asthma, recurrent pulmonary infiltrates, immediate wheal and flare skin reactivity to A. fumigatus, elevated total serum IgE levels, detectable serum precipitating antibodies to A. fumigatus, peripheral blood eosinophilia, elevated levels of Aspergillus-specific serum IgE and central bronchiectasis with normal distal structures. The diagnosis of ABPA should be considered in asthmatics of all ages. Evolution of the disease comprises five stages from the acute to the fibrotic stage including pulmonary fibrosis and respiratory insufficiency. The goals of ABPA treatment are to control patient's asthma and prevent exacerbations of ABPA. During the acute stage, prednisone should be administered. Antifungals agents (itraconazole) may be useful to prevent exacerbations of the disease.

Coexisting atopic conditions influence the likelihood of allergic bronchopulmonary aspergillosis in asthma

BackgroundThe diagnosis of allergic bronchopulmonary aspergillosis (ABPA) in asthma is often made in patients with total serum IgE levels greater than 1,000 IU/mL in conjunction with evidence of Aspergillus sensitization. The specificity of total serum IgE for the diagnosis of ABPA is low even when combined with serum Aspergillus specific IgE. ObjectiveTo determine the prevalence of ABPA and to identify alternative clinical predictors for ABPA among asthmatic patients with a total serum IgE level greater than 1,000 IU/ml. MethodsThis study was conducted in a tertiary hospital in Melbourne, Australia, with a large asthma and allergy service. Patients with asthma and total serum IgE levels greater than 1,000 IU/ml from January 1, 2005, through December 31, 2014, were included. Patients were considered to have concomitant allergic conditions if they had atopic eczema, allergic rhinitis, or both. The diagnosis of ABPA was based on the managing physician's documented diagnosis and referenced to criteria proposed by the International Society for Human and Fungal Mycology. ResultsThe prevalence of ABPA in our cohort was 15.8%. Older age, elevated total serum IgE level, reduced lung function, and the absence of other concomitant allergic conditions increased the risk of ABPA. After multivariate logistic regression, patients without concomitant allergic conditions had an odds ratio of 4.4 (95% confidence interval, 1.9–10.1; P = .001) for ABPA when compared with patients with allergic conditions. ConclusionThe absence of atopic eczema and allergic rhinitis in these patients increases the likelihood of ABPA. Eliciting an accurate allergy history may be a useful bedside clinical tool when considering the diagnosis of ABPA.

A role ofFCER1AandFCER2polymorphisms in IgE regulation

Both FCER2 and FCER1A encode subunits of IgE receptors. Variants in FCER1A were previously identified as major determinants of IgE levels in genome-wide association studies. Here we investigated in detail whether FCER2 polymorphisms affect IgE levels alone and/or by interaction with FCER1A polymorphisms. To cover the genetic information of FCER2, 21 single-nucleotide polymorphisms (SNPs) were genotyped by Illumina HumanHap300 BeadChip (5 SNPs) and the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS; 14 SNPs) in at least 1303 Caucasian children (651 asthmatics) (ISAAC II/ MAGICS population); genotypes of two SNPs were imputed. SNP rs3760687 showed the most consistent effect on total serum IgE levels (b [SE]=-0.38 [0.16]; P=0.016), while FCER2 polymorphisms in general were predominantly associated with mildly-to-moderately increased IgE levels (50th and 66th percentiles). Gene-by-gene interaction analysis suggests that FCER2 polymorphism rs3760687 influences IgE levels mainly in individuals not homozygous for the risk allele of FCER1A polymorphism rs2427837, which belongs to the major IgE-determining tagging bin in the population. FCER2 polymorphism rs3760687 affects moderately elevated total serum IgE levels, especially in the absence of homozygosity for the risk allele of FCER1A SNP rs2427837.

Heterogeneity in presentation and treatment of catamenial anaphylaxis

BackgroundFew reports have documented the uncommon association of the female menstrual cycle with anaphylaxis, an entity known as cyclic or catamenial anaphylaxis. ObjectiveTo examine cases of perimenstrual anaphylaxis, focusing on differences in presentation and response to treatment, in the hopes of enriching the description of this rare entity. MethodsA cohort of 8 women with catamenial anaphylaxis were identified and retrospectively compared with regard to age at onset, organ involvement, diagnostic studies, and response to therapy. ResultsThe median age at onset was 34 years (range, 14-40 years), and the median number of perimenstrual anaphylactic episodes at presentation was 10 per patient (range, 4-24 per patient). Most had cutaneous and gastrointestinal symptoms. The results of extensive investigations for anaphylactic triggers were negative, and masquerading conditions, such as carcinoid syndrome, pheochromocytoma, and systemic mastocytosis, were ruled out in all patients. Skin test results for progesterone were negative in all but 1 of 4 patients tested. None had elevated total serum IgE levels. Response to suppressive treatments regimens varied considerably, but none treated with high-dose systemic steroids had improvement. Similarly, ketotifen, celecoxib, rofecoxib, and oral contraceptives failed to control the anaphylactic reactions. Although antihistamines failed in 7 patients, 1 had improvement. Others responded to leuprolide, medroxyprogesterone, or salpingo-oophorectomy. ConclusionWhether the mechanism causing cyclical anaphylaxis may involve hypersensitivity to progesterone or prostaglandins, the variable response to suppressive medications in these cases suggests that catamenial anaphylaxis is a heterogeneous disorder in which a number of mechanisms and mediators may play a role. It is an emergent and probably underrecognized entity in the medical literature.

Sequential IgE-Targeted Therapy Combining Immunapheresis And Omalizumab In Patients With Severe Atopic Dermatitis And Grossly Elevated Total Serum IgE Levels - A Pilot Trial

To evaluate the role of IgE in atopic dermatitis (AD) by combining immunoglobulin (Ig)-apheresis and anti-IgE-antibody omalizumab to reduce IgE in patients with severe, therapy-refractory AD and grossly elevated IgE levels.

Non-atopic IgE and eosinophil cationic protein after allogeneic hematopoietic stem cell transplantation in children

Allogeneic hematopoietic stem cell transplantation (HSCT) in childhood is associated with severe pulmonary complications, but the pathophysiologic mechanisms remain unclear. Our aim was to evaluate the association of total and specific IgE, eosinophil cationic protein (ECP) and eosinophilia in HSCT recipients with pulmonary complications. We prospectively measured total and specific serum IgE, eosinophils, and ECP before and 28, 100, and 180 days after HSCT. We included 30 children (age 2–17 years) undergoing HSCT. Nine patients had a history of previous atopy without being associated with pulmonary complications after HSCT until day +360. Specific IgE levels showed a decline after HSCT, associated with the absence of allergy symptoms, suggesting a reduction of atopy. Elevated total serum IgE levels occurred in seven patients on day +28 after HSCT. This elevation did not coincide with allergy symptoms. ECP showed no correlation with total allergy symptoms, eosinophilia, IgE levels, or pulmonary complications. There was a significant correlation (p = 0.0367) between ECP levels on day +28 and concurrent acute graft-versus-host disease (GvHD). Non-atopic serum ECP and IgE levels are elevated on day +28 after HSCT in children, with ECP showing a potential relation to acute GvHD.

ABPA Concomitantly Occurring with Invasive Sinus Aspergillosis: A Short Report on Two Patients

Allergic bronchopulmonary aspergillosis (ABPA) is a pulmonary disorder that is caused by hypersensitivity to Aspergillus fumigatus with resultant systemic immune activation, chronic asthma, recurrent pulmonary infiltrates, and bronchiectasis. First described by Hinson et al. (Thorax 7:317-333 [1]) in 1952, this disease occurs in 1-2% of patients with persistent asthma and in 2-15% of patients with cystic fibrosis (Greenberger, Front Biosci 8:s119-s127 [2]). Although the diagnostic criteria for ABPA have been laid down (and include bronchial asthma, immediate skin test reactivity to A. fumigatus, elevated total serum IgE level, pulmonary infiltrates, central bronchiectasis, peripheral blood eosinophilia, and positive serum precipitins [IgG] against Aspergillus antigen), none of these are specific for ABPA (Shah, Curr Opin Pulm Med 13(1):72-80 [3]). There is still no consensus on the number of criteria needed for diagnosis, and patients in different stages of ABPA may not fulfill all these criteria (Greenberger, Front Biosci 8:s119-s127 [2]; Chakrabarti et al., Mycoses 45:295-299 [4]). An high-resolution CT (HRCT) scan showing central bronchiectasis and high attenuation mucus is presently the investigation of choice for the diagnosis of bronchiectasis in patients with ABPA (Shah, Front Biosci 8:e138-e146 [5]). ABPA has also been reported in association with allergic fungal rhinosinusitis in English literature (Shah, Curr Opin Pulm Med 13(1):72-80 [3]). We are reporting two patients with invasive aspergillosis of the nose, paranasal sinuses and orbit, who were diagnose and managed successfully for ABPA, a previously unreported entity.

A Case of Pulmonary Paragonimiasis with Involvement of the Abdominal Muscle in a 9-Year-Old Girl

In Korea, many people enjoy eating raw or underkooked freshwater crayfish and crabs which unfortunately may cause paragonimiasis. Here, we describe a case of pulmonary and abdominal paragonimiasis in a 9-year-old girl, who presented with a 1-month history of abdominal pain, especially in the right flank and the right inguinal area, with anorexia. A chest radiograph revealed pleural effusion in both lungs, and her abdominal sonography indicated an inflammatory lesion in the right psoas muscle. Peripheral blood analysis of the patient showed hypereosinophilia (66.0%) and an elevated total serum IgE level (>2,500 IU/ml). The pleural effusion tested by ELISA were also positive for antibodies against paragonimiasis. Her dietary history stated that she had ingested raw freshwater crab, 4 months previously. The diagnosis was pulmonary paragonimiasis accompanied by abdominal muscle involvement. She was improved after 5 cycles of praziquantel treatment and 2 times of pleural effusion drainage. In conclusion, herein, we report a case of pulmonary and abdominal paragonimiasis in a girl who presented with abdominal pain and tenderness in the inguinal area.

Genetic Polymorphism of Manganese Superoxide Dismutase is Associated with Childhood Asthma

Objective. Cellular defenses against allergens and reactive oxygen species (ROS) exposure are critical in the pathogenesis of asthma. CD14 is a receptor for various bacterial products, such as lipopolysaccharides (LPS), and is also a mediator of inflammatory processes. Manganese superoxide dismutase (MnSOD) is an ROS scavenger, and myeloperoxidase (MPO) can convert hydrogen peroxide into hypochlorous acid; thus, they are considered to be involved in inflammatory defense. The authors conducted a case-control study to evaluate the susceptibility to childhood asthma based on CD14, MnSOD, and MPO genes. Methods. The CD14 −260, MnSOD −9, and MPO −463 genotypes were identified by polymerase chain reactions for 116 asthmatic children and 232 healthy controls. Questionnaires were administered to obtain demographic characteristics. Allergen testing used common Taiwanese aeroallergens. Results. A higher level of parental education, family history of asthma, incense burning at home, allergen-test positive, and the MnSOD Val-Ala/Ala-Ala genotypes (matched relative risk = 2.0; 95% confidence interval = 1.0–4.2) were significantly associated with childhood asthma. Interactions between CD14, MnSOD, MPO genotypes and allergy status were significantly associated with asthma risk in these children (all p <.001). Furthermore, atopic cases with MnSOD Val-Ala/Ala-Ala (log eosinophil 2.66/mm3, log total serum immunoglobulin E [IgE] 2.48 IU/ml) or Val-Val (log eosinophil 2.61/mm3, log total serum IgE 2.63 IU/ml) genotypes had elevated eosinophil counts and total serum IgE levels as compared to nonatopic cases with MnSOD Val-Val genotype (log eosinophil 2.27/mm3, log total serum IgE 1.83 IU/ml). Conclusions. Susceptible MnSOD genotypes might modulate the development of asthma in Taiwanese children.

Artritis séptica en un caso de síndrome de hiperinmunoglobulinemia E

Hyper-IgE syndrome (HIES) is characterized by recurrent skin and pulmonary infections (mainly bacterial), eczematous dermatitis and elevated serum IgE levels. Associated abnormalities in some patients include coarse facial features, failure or delay of shedding of primary teeth, recurrent fractures, hyperextensible joints, and scoliosis. Laboratory abnormalities include elevated total serum IgE levels, typically ranging from 1000 to greater than 50,000 IU/mL and variable eosinophilia. The diagnosis of HIES is based upon the presence of suggestive clinical and laboratory findings. A definitive laboratory test is not commercially available at present. Management of patients with HIES is focused on skin care, prevention of infection, prompt and complete treatment of infections that do develop, and control of pulmonary complications.

L’aspergillose en pratique pour le pneumologue

Aspergillus is involved in various lung illnesses related to type of exposition and immunity host response, local (tracheobronchial) and global. Allergic bronchopulmonary aspergillosis is due to a hypersensitivity response, diagnosis must be considered in presence of severe asthma with radiologic opacities, blood eosinophilia and elevated total serum IgE levels. Bronchial colonization is often accidentally discovered, but needs a monitoring. Pulmonary aspergilloma, often asymptomatic, grows in a preexisting cavity. Aspergillus bronchitis is a prolonged superficious endobronchial infection. Pseudomembranous necrotizing tracheobronchitis is a microinvasive bronchial infection, which prognosis is very bad. Acute invasive pulmonary aspergillosis affects quite always immunocompromised patients, but cases are not exceptional in patients with prior lung disease. Chronic necrotizing pulmonary aspergillosis may be divided in chronic cavitary and chronic fibrosing pulmonary aspergillosis, and subacute invasive aspergillosis according to the course of the disease, radiological outcome first. Management of diseases caused by Aspergillus is evolving with new diagnostic tools (PCR, Aspergillus antigenemia) and with new generation antifungal drugs.

Molecular pathogenesis and clinical implications of eczema herpeticum

A subgroup of patients with atopic dermatitis develops one or more episodes of a severe viral skin infection caused by herpes simplex virus superimposed on eczematous skin lesions. This condition is named atopic dermatitis complicated by eczema herpeticum. Characteristic features of patients developing eczema herpeticum include an early age of onset of atopic dermatitis with a persistent and severe course into adulthood, predilection for eczematous skin lesions in the head and neck area, elevated total serum IgE levels and increased allergen sensitisation. Deficiencies at the level of both the innate and the adaptive immune system, which have been identified in atopic dermatitis, are much more pronounced in this subgroup. Predisposing cellular factors include a reduced number of plasmacytoid dendritic cells in the epidermis and a modified capacity of these cells to produce type I interferons after allergen challenge. In addition, lower levels of antimicrobial peptides in the skin of atopic dermatitis patients, resulting in part from a Th2-prone micromilieu, contribute to the lack of an effective defence against viral attack. In this review, we summarise the current knowledge of the molecular pathogenesis of eczema herpeticum.