The clinical spectrum and therapeutic challenge of eczema herpeticum

Papulovesicular Riddle in an Atopic Individual

Atopic dermatitis (AD) characterized by pruritus and eczematous lesions makes individuals susceptible to various viral and bacterial infections. Eczema herpeticum (EH), also known as Kaposi's varicelliform eruption, is a severe herpes simplex virus infection that can be observed in individuals with AD. EH manifests with monomorphic vesicles and "punched-out" erosions accompanied by hemorrhagic crusts, primarily affecting eczematous areas. Misdiagnosis, often as impetigo, can lead to severe complications and even death. Timely diagnosis and treatment with acyclovir are crucial to avert these outcomes. Here we present a case of a 19-year-old male with AD who presented with a monomorphic vesicular rash.

Skin of colour: essentials for the non-dermatologist

Doctors-in-training often receive an inadequate dermatology education. Furthermore, studies have highlighted the under-representation of skin of colour (SOC) in dermatological teaching, learning resources and research. Our image-based questionnaire, distributed to all internal medicine trainees in southwest England, highlighted knowledge gaps regarding SOC among training physicians. It is intrinsically more challenging for clinicians to confidently formulate dermatological diagnoses in SOC. In this review, we provide guidance for physicians to help make the diagnostic process more straightforward. First, we outline how skin colour is determined and classified. We discuss how inflammation presents in SOC, with the typical 'erythema' that physicians often associate with inflammation being a less prominent feature in darker skin tones. We then summarise nine important conditions that we believe physicians working in all specialties should be able to identify in patients with SOC, covering both conditions encountered on the medical take and conditions disproportionately affecting individuals with SOC. The population of the UK is rapidly diversifying; thus, as physicians, we have a professional duty to educate ourselves on dermatological conditions in SOC to provide the best quality of care for all our patients, regardless of their skin type.

A rare case of eczema herpeticum associated with HIV: A case report

Eczema herpeticum (EH), also known as Kaposi's varicelliform eruption, is a disseminated herpes simplex virus infection seen in patients with underlying skin conditions, most commonly atopic dermatitis. Monomorphic vesicles and "punched-out" erosions with hemorrhagic crusts over eczematous regions are the hallmarks of EH's presentation. Here, we discuss a first reported case of eczema herpeticum in a patient living with well controlled HIV with prior steroid use. A 30-year-old male patient living with HIV presented to the hospital with a generalized rash involving the face, neck, arms, hands, low back region, and both feet. Herpes simplex 1 and 2 by PCR DNA were detected from external auditory ear canal drainage. The patient was treated with intravenous acyclovir and responded well. He had long term history of eczema and required acyclovir prophylaxis later.

Eczema Herpeticum: Clinical and Pathophysiological Aspects

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease in the world. AD is a complex pathology mainly characterized by an impaired skin barrier, immune response dysfunction, and unbalanced skin microbiota. Moreover, AD patients exhibit an increased risk of developing bacterial and viral infections. One of the most current, and potentially life-threatening, viral infection is caused by herpes simplex virus (HSV), which occurs in about 3% of AD patients under the name of eczema herpeticum (EH). Following a first part dedicated to the clinical features, virological diagnosis, and current treatments of EH, this review will focus on the description of the pathophysiology and, more particularly, the presently known predisposing factors to herpetic complications in AD patients. These factors include those related to impairment of the skin barrier such as deficit in filaggrin and anomalies in tight and adherens junctions. In addition, low production of the antimicrobial peptides cathelicidin LL-37 and human β-defensins; overexpression of cytokines such as interleukin (IL)-4, IL-13, IL-25, IL-33, and thymic stromal lymphopoietin (TSLP); or downregulation of type I to III interferons as well as defect in functions of immune cells such as dendritic, natural killer, and regulatory T cells have been involved. Otherwise, genetic polymorphisms and AD topical calcineurin inhibitor treatments have been associated with an increased risk of EH. Finally, dysbiosis of skin microbiota characterized in AD patients by Staphylococcus aureus colonization and toxin secretion, such as α-toxin, has been described as promoting HSV replication and could therefore contribute to EH.

The infectious complications of atopic dermatitis

OBJECTIVE

Atopic dermatitis (AD) is a chronic inflammatory skin disease that is complicated by an increased risk for skin and systemic infections. Preventive therapy for AD is based on skin barrier improvement and anti-inflammatory treatments, whereas overt skin and systemic infections require antibiotics or antiviral treatments. This review updates the pathophysiology, diagnosis, management, controversy of antibiotic use, and potential treatments of infectious complications of AD.

DATA SOURCES

Published literature obtained through PubMed database searches and clinical pictures.

STUDY SELECTIONS

Studies relevant to the mechanisms, diagnosis, management, and potential therapy of infectious complications of AD.

RESULTS

Skin barrier defects, type 2 inflammation, Staphylococcusaureus colonization, and cutaneous dysbiosis are the major predisposing factors for the increased infections in AD. Although overt infections require antibiotics, the use of antibiotics in AD exacerbation remains controversial.

CONCLUSION

Infectious complications are a comorbidity of AD. Although not common, systemic bacterial infections and eczema herpeticum can be life-threatening. Preventive therapy of infections in AD emphasizes skin barrier improvement and anti-inflammatory therapy. The use of antibiotics in AD exacerbation requires further studies.

Biologics for Atopic Dermatitis

Atopic dermatitis (AD) is a common chronic inflammatory skin disease that has become a global health problem. The pathophysiology of AD includes both skin barrier and immune abnormalities, with type 2 immune deviation central to several clinical phenotypes and underlying endotypes. Recognition of the persistent nature and systemic aspects of AD provides a rationale for treatment with a biologic. Dupilumab has been approved for patients 6 years of age and older with moderate to severe AD. Monoclonal antibodies are in phase 3 trials and may become part of a precision medicine approach to AD.

Frequency and Clinical Features Associated With Eczema Herpeticum in Hospitalized Children With Presumed Atopic Dermatitis Skin Infection

BACKGROUND

Atopic dermatitis (AD) predisposes to viral skin infections, such as eczema herpeticum (EH), and to bacterial skin infections, such as those caused by Staphylococcus aureus (SA) and group A streptococcus (GAS). This study evaluated clinical features of EH and its frequency of codetection with SA or GAS in children hospitalized for presumed AD skin infection.

METHODS

We retrospectively reviewed clinical data for children ≤18 years of age admitted to a large hospital system for AD with presumed skin infection from January 2004 to December 2018. Those with an alternate primary diagnosis or missing microbiologic data were excluded. Encounters with herpes simplex virus testing were identified as AD with EH (ADEH+) or without (ADEH-). Encounters with bacterial skin culture growth were identified as SA or GAS.

RESULTS

Among 180 AD encounters with suspected skin infection, 133 (74%) were tested for herpes simplex virus. Clinical findings associated with ADEH+ status (n = 61) included fever on admission (59% vs. 32% in ADEH-; P = 0.002), rash on the neck (30% vs. 13%; P = 0.015) and vesicular rash (70% vs. 49%; P = 0.011). Encounters in the ADEH+ group had a longer hospital length of stay compared with encounters in the ADEH- group [median 4 days (interquartile range 3-5 days) vs. 3 days (interquartile range 2-3 days); P < 0.001]. GAS was identified in only 1 ADEH+ encounter (2%) versus 15 ADEH- encounters (26%), P < 0.001.

CONCLUSIONS

Providers should maintain a high index of suspicion for EH in children admitted for presumed AD skin infection. GAS was more commonly associated with ADEH- encounters.

An 8-Month-Old Girl With Vesicular Rash

This is a case report of an 8-month-old girl who presented to the pediatric emergency department with vesicular rash and fever. She was diagnosed with eczema herpeticum (EH). EH is an acute, rapidly progressive rare dermatologic disease, and if it is not treated promptly, it can cause life-threatening complications. It often occurs in a patient with an underlying skin disorder, such as atopic dermatitis or other erosive dermatoses. Diagnosis is mainly made by clinical examination usually presented as many very similar shaped and sized eroded vesicles. It is important for clinicians to recognize the sign and symptoms of EH and have a high suspicion for patients with atopic dermatitis who present with rapidly disseminating blisters. Treatment is with oral or intravenous acyclovir. If the patient has widespread eruptions or systemic symptoms such as fever, malaise, and poor oral intake, the patient should be admitted for intravenous acyclovir.

Biologic Therapy for Atopic Dermatitis: Moving Beyond the Practice Parameter and Guidelines

Atopic dermatitis (AD), a common chronic pruritic inflammatory skin disease, impacts the quality of life of patients and caregivers and has become a global health problem. It is increasingly recognized as a disease not only of children but also of adults who may have a persistent or relapsing course from childhood or who develop new-onset adult disease. Besides well-established atopic comorbidities, associations with a number of nonatopic comorbidities have been reported. AD is characterized by both immune dysregulation and epidermal barrier dysfunction. The findings that nonlesional skin in AD has both terminal keratinocyte differentiation defects and immune abnormalities as well as multiple markers of immune and inflammatory activation in the circulation point to the systemic nature of the disease and have important translational implications. Although AD is predominantly associated with type 2 immune responses, activation of other cytokine pathways including T_H1, T_H22, and T_H17/IL-23 has been reported, suggesting potential therapeutic targets and provide a rationale for treatment with novel biologics. Dupilumab, a fully human mAb targeting the IL-4 Rα subunit, blocks signaling of both IL-4 and IL-13 and is the first biologic to be approved for the treatment of moderate-to-severe AD in adult patients. Other biologics in current trials for AD are targeting the IL-31 receptor, IL-13, and the common p40 subunit of IL-12/IL-23.

Paradoxic eczema in infants after heart transplantation

New-onset psoriasis in patients receiving tumor necrosis factor inhibitors is well recognized in children and adults. We describe three children who underwent cardiac transplantation and developed an analogous form of paradoxic eczema occurring 2-48 months after starting systemic tacrolimus, a drug widely used topically to treat eczema. Anecdotal reports and our experience suggest that tacrolimus taper with alternative systemic antirejection immunosuppressant may lead to skin clearance. Pending additional insight, treatment should include optimizing skin barrier function, minimizing microbial and allergic triggers, and coordinating care to choose the best-tolerated systemic immunosuppressant regimen at the lowest effective dose.

Characterization of children with recurrent eczema herpeticum and response to treatment with interferon-gamma

BACKGROUND/OBJECTIVES

Interferon gamma (IFN-γ) has been used treat severe atopic dermatitis, with equivocal results. Recurrent eczema herpeticum is an underappreciated, therapeutically challenging complication of severe atopic dermatitis. Defects in IFN-γ and other cytokine pathways have been identified in individuals with confirmed eczema herpeticum. This suggests possible benefit from IFN-γ treatment for confirmed eczema herpeticum. The objective of the current study was to evaluate immunologic and microbial parameters and response to IFN-γ treatment in children with confirmed eczema herpeticum.

METHODS

We performed a retrospective review of medical records from eight children with confirmed eczema herpeticum and two children with severe atopic dermatitis without a history of eczema herpeticum treated with subcutaneous IFN-γ.

RESULTS

Our cohort of children with confirmed eczema herpeticum was predominantly male and had high total serum immunoglobulin E, evidence of insufficient toll-like receptor responses, and streptococcal skin and pharyngeal colonization. The duration of IFN-γ administration was 4.5-25 months. Five children had initial control and then relapse. Three had interval flares. Two had no improvement. Injections were well tolerated, without significant adverse effects. Treatment was associated with an increase in total immunoglobulin E. Poor adherence complicated therapy in five patients. All 10 discontinued IFN-γ for poor perceived efficacy.

CONCLUSION

Children with confirmed eczema herpeticum have evidence of impaired innate and adaptive immunity. IFN-γ did not result in dramatic improvement in either subset. Specific evaluation for IFN-γ production, function, or receptor defects may help predict response.

Characterization of Herpes Simplex Virus Infections Seen in the Pediatric Dermatology Office

BACKGROUND/OBJECTIVES

Atypical and severe clinical manifestations of primary and recurrent herpes simplex virus (HSV) infections may present to a pediatric dermatologist for evaluation. The purpose of this study was to characterize the clinical features of the population diagnosed with HSV referred to a pediatric dermatology office.

METHODS

This retrospective case series examined patients diagnosed with HSV in a pediatric dermatology practice at an academic medical center from 2005 to 2015. Characteristics of the population were collected and analyzed.

RESULTS

In this study of 48 children diagnosed with HSV, 33% presented at age 2 years or younger, with approximately half having exhibited initial symptoms before 2 years of age; 39.6% of the population had six or more outbreaks per year. The outbreaks were equally divided between unifocal and multifocal presentations, with 60% of children without any labial or mucosal involvement. Suppressive treatment was initiated in 33% of patients; the average age at initiation was 6 years.

CONCLUSION

Our data characterize a subset of immunocompetent young children who present to pediatric dermatologists with frequent HSV outbreaks that are often multifocal and involve cutaneous sites, with or without mucosal involvement.

Relationship Between the Presence of Eczema Herpeticum and the Significance of Clinical and Laboratory Tests in Korean Children With Atopic Dermatitis

BACKGROUND

Eczema herpeticum (EH) is a herpes simplex virus (HSV) infection superimposed on atopic dermatitis (AD).

OBJECTIVES

The aim of this study was to evaluate the relationship between clinical features and laboratory tests, including skin cultures, total IgE, eosinophil count, eosinophil cationic protein, and 25-hydroxyvitamin D₃ (25-(OH)D3), in Korean children with AD according to the presence of EH.

PATIENTS AND METHODS

We enrolled 380 patients aged 6 months to 18 years who were admitted to Busan St. Mary's hospital from January 2012 to December 2014. All 380 subjects were divided into two groups: the control and the AD group. The AD group was further divided into two subgroups: EH⁺ and EH^-.

RESULTS

The male gender was related to the presence of EH (odds ratio of 2.56; 95% confidence interval, 1.19 - 5.53, P = 0.01), but age and 25-(OH)D₃ levels were not. After adjusting for age, gender, and 25-(OH)D₃, no significant relationship was found between total IgE, eosinophil cationic protein or eosinophil count levels and the presence of EH. The relationship between positive skin cultures and the presence of EH was significant (P < 0.001) and the presence of methicillin-resistant Staphylococcus aureus (MRSA) was also related to the development of EH (OR, 0.19; 95% CI, 0.04 - 0.92, P = 0.03).

CONCLUSIONS

We conclude that while male gender, positive skin culture results, and the presence of MRSA are factors influencing EH, serum 25-(OH)D₃ levels are not associated with EH in Korean AD children.

Synthetic α-Hydroxytropolones Inhibit Replication of Wild-Type and Acyclovir-Resistant Herpes Simplex Viruses

Herpes simplex virus 1 (HSV-1) and HSV-2 remain major human pathogens despite the development of anti-HSV therapeutics as some of the first antiviral drugs. Current therapies are incompletely effective and frequently drive the evolution of drug-resistant mutants. We recently determined that certain natural troponoid compounds such as β-thujaplicinol readily suppress HSV-1 and HSV-2 replication. Here, we screened 26 synthetic α-hydroxytropolones with the goals of determining a preliminary structure-activity relationship for the α-hydroxytropolone pharmacophore and providing a starting point for future optimization studies. Twenty-five compounds inhibited HSV-1 and HSV-2 replication at 50 μM, and 10 compounds inhibited HSV-1 and HSV-2 at 5 μM, with similar inhibition patterns and potencies against both viruses being observed. The two most powerful inhibitors shared a common biphenyl side chain, were capable of inhibiting HSV-1 and HSV-2 with a 50% effective concentration (EC50) of 81 to 210 nM, and also strongly inhibited acyclovir-resistant mutants. Moderate to low cytotoxicity was observed for all compounds (50% cytotoxic concentration [CC50] of 50 to >100 μM). Therapeutic indexes ranged from >170 to >1,200. These data indicate that troponoids and specifically α-hydroxytropolones are a promising lead scaffold for development as anti-HSV drugs provided that toxicity can be further minimized. Troponoid drugs are envisioned to be employed alone or in combination with existing nucleos(t)ide analogs to suppress HSV replication far enough to prevent viral shedding and to limit the development of or treat nucleos(t)ide analog-resistant mutants.

Infection or allergy? The multifaceted nature of vulvar dermatoses

Chronic dermatitis or pruritus affecting the female genital and perianal skin can be challenging to properly diagnose and manage. The differential diagnosis generally includes allergic, inflammatory, infectious, and neoplastic conditions. We report the case of a 52-year-old woman with a 6-month history of a progressive, debilitating vulvar and perianal rash that highlights the multifaceted nature of female genital dermatoses.

Diagnosis of Atopic Dermatitis: Mimics, Overlaps, and Complications

Atopic dermatitis (AD) is one of the most common skin diseases affecting infants and children. A smaller subset of adults has persistent or new-onset AD. AD is characterized by pruritus, erythema, induration, and scale, but these features are also typical of several other conditions that can mimic, coexist with, or complicate AD. These include inflammatory skin conditions, infections, infestations, malignancies, genetic disorders, immunodeficiency disorders, nutritional disorders, graft-versus-host disease, and drug eruptions. Familiarity of the spectrum of these diseases and their distinguishing features is critical for correct and timely diagnosis and optimal treatment.

Clinical pearls from atopic dermatitis and its infectious complications

Atopic dermatitis (AD) is clinically very heterogeneous and these differences can cause confusion. Differential diagnosis is also complicated by co-infections, particularly in infancy and early childhood. This paper describes the stages and differential diagnosis during the various stages of childhood. The authors also provide advice on how to distinguish between AD and other disorders together with guidance on tackling common issues with treatment such as steroid phobia.

Eczema herpeticum with herpetic folliculitis after bone marrow transplant under prophylactic acyclovir: are patients with underlying dermatologic disorders at higher risk?

We present an unreported coexistence: eczema herpeticum (EH) with histopathological findings of herpetic folliculitis (HF) after allogeneic bone marrow transplantation (BMT). A patient with atopic dermatitis (AD) underwent allogeneic BMT for idiopathic acquired aplastic anemia. She had been receiving cyclosporine (150 mg/12 h) and acyclovir (400 mg/12 h) for 6 months. A facial rash was observed, composed of monotonous erythematous, umbilicated papulo-vesicles and papulo-crusts <4 mm in size. The histopathological study showed herpetic cytopathic changes within the epidermis that extended into the hair follicle epithelium. Interestingly, microscopic HF has not previously been associated with post-transplant patients or EH. However, it is reasonable to hypothesize that the coexistence of these herpes simplex virus-related events may be underreported in the literature. Although further studies are necessary, we suggest that the prophylactic antiviral dose after BMT be enhanced in patients with underlying dermatologic diseases, especially in those with AD.

Eczema herpeticum in children: clinical features and factors predictive of hospitalization

OBJECTIVE

To describe the clinical characteristics of pediatric patients with eczema herpeticum and to determine the predictors of hospitalization, and recurrence and repeat episodes.

STUDY DESIGN

A retrospective cohort study of patients 0-18 years of age diagnosed with eczema herpeticum between May 2000 and April 2009 was carried out at a tertiary pediatric care center in Canada. Seventy-nine patients were included. The primary outcome was hospitalization; secondary outcomes were recurrent and repeat episodes of eczema herpeticum.

RESULTS

At presentation, 76% of 79 patients with eczema herpeticum had a generalized eruption, 56% had fever, 37% had systemic symptoms, and 10% had eye involvement (keratoconjunctivitis). Forty-five patients (57%) were hospitalized. Predictors for hospitalization included male sex (OR = 3.09; 95% CI, 1.20-7.95, P = .017), fever (OR = 5.75; 95% CI, 2.17-15.26, P < .001), systemic symptoms (OR = 2.84; 95% CI, 1.06-7.62, P = .035), and age <1 year (OR = 7.17; 95% CI, 2.17-23.72, P = .001). Recurrence rate (<1 month) was 8.9% and rate of repeat episodes (>1 month) was 16%. Hospitalized patients were more likely to have a repeat episode (OR = 8.25; 95% CI, 0.99-68.69, P = .05). Patients with a previous history of eczema herpeticum had increased likelihood of early recurrence (OR = 6.80; 95% CI, 0.99-46.62, P = .05) and repeat episodes (OR = 9.43; 95% CI, 1.52-55.9, P = .01).

CONCLUSIONS

Predictors of hospitalization in this cohort included male sex, age <1 year, fever, and systemic symptoms at presentation. Hospitalized patients may be at risk for repeat episodes of eczema herpeticum.

Comorbidity in Atopic Dermatitis

The negative impact of atopic dermatitis (AD) often extends beyond the skin. Children with AD experience increased rates of infectious, mental health, and allergic diseases compared to their non-atopic peers. The mechanisms underlying these associations remain elusive. New insights from genetic and epidermal research pinpoint the skin barrier as a primary initiator of AD. Epicutaneous sensitization represents an intriguing new model which links a disrupted skin barrier to the later development of IgE-mediated diseases in patients with AD. Recent epidemiological studies have identified new comorbidities linked to AD as well, including several mental health disorders and obesity. This manuscript reviews the recent literature regarding both classic and newly described AD comorbidities.

Pediatric dermatology emergencies

PURPOSE OF REVIEW

The purpose of this review is to summarize recent advances in the diagnosis and treatment of several severe skin diseases seen in children.

RECENT FINDINGS

Several articles published recently added significantly to our understanding of drug reaction with eosinophilia and systemic symptoms (DRESS), eczema herpeticum, staphylococcal scalded skin syndrome and inherited ichthyosis. A review of 60 patients with DRESS showed 80% with hepatic involvement, 40% with renal involvement, 33% with pulmonary involvement and 50% with hematologic abnormalities. A review on eczema herpeticum describes several clinical scenarios in which it is vital to keep that diagnosis in mind. Another review on severe staphylococcal skin infections reminds us of the importance of covering for methicillin-resistant Staphylococcus aureus in all such cases until cultures and sensitivities show otherwise. The results of an international consensus conference on ichthyosis published this year will help all of us to better characterize these complicated patients. Additionally, the first case of hypothyroidism associated with a collodion baby was reported, as was the finding of an increased incidence of atypical nevi in patients with inherited ichthyosis.

SUMMARY

Although all of the conditions discussed in this article are relatively rare, it is important that they be kept on the differential diagnosis for sick infants and children with cutaneous findings, as early diagnosis and treatment of some of these conditions can be life saving.