Exogenous factors in the pathogenesis of atopic dermatitis: Irritants and cutaneous infections.

Atopic dermatitis (AD) is a chronic relapsing inflammatory cutaneous disease that is often associated with other atopic symptoms, such as food allergy, allergic rhinitis and asthma, leading to significant morbidity and healthcare costs. The pathogenesis of AD is complicated and multifactorial. Although the aetiology of AD remains incompletely understood, recent studies have provided further insight into AD pathophysiology, demonstrating that the interaction among genetic predisposition, immune dysfunction and environmental provocation factors contributes to its development. However, the increasing prevalence of AD suggests that environmental factors such as irritation and cutaneous infection play a crucial role in triggering and/or aggravating the disease. Of note, AD skin is susceptible to bacterial, fungal and viral infections, and microorganisms may colonize the skin and aggravate AD symptoms. Overall, understanding the mechanisms by which these risk factors affect the cutaneous immunity of patients with AD is of great importance for developing a precision medicine approach for treatment. This review summarizes recent developments in exogenous factors involved in the pathogenesis of AD, with special emphasis on irritants and microbial infections.

Molluscum Contagiosum: An Update.

BACKGROUND: Molluscum contagiosum is a viral cutaneous infection in childhood that occurs worldwide. Physicians should familiarize themselves with this common condition. OBJECTIVE: To review in depth the epidemiology, pathophysiology, clinical manifestations, complications and, in particular, treatment of molluscum contagiosum. METHODS: A PubMed search was completed in Clinical Queries using the key term "molluscum contagiosum". Patents were searched using the key term "molluscum contagiosum" from www.google.com/patents, http: //espacenet.com, and www.freepatentsonline.com. RESULTS: Molluscum contagiosum is caused by a poxvirus of the Molluscipox genus. Preschool and elementary school-aged children are more commonly affected. The virus is transmitted by close physical contact, autoinoculation, and fomites. Typically, molluscum contagiosum presents as asymptomatic, discrete, smooth, flesh-colored, dome-shaped papules with central umbilication from which a plug of cheesy material can be expressed. Some authors suggest watchful waiting of the lesions.Many authors suggest active treatment of lesions for cosmetic reasons or concerns of transmission and autoinoculation. Active treatments may be mechanical (e.g. cryotherapy, curettage, pulsed dye laser therapy), chemical (e.g. cantharidin, potassium hydroxide, podophyllotoxin, benzoyl peroxide, tretinoin, trichloroacetic acid, lactic acid, glycolic acid, salicylic acid), immune-modulating (e.g. imiquimod, interferon-alpha, cimetidine) and anti-viral (e.g. cidofovir). Recent patents related to the management of molluscum contagiosum are also retrieved and discussed. These patents comprise of topical compositions and herbal Chinese medicine with limited documentation of their efficacy. CONCLUSION: The choice of treatment method should depend on the physician's comfort level with the various treatment options, the patient's age, the number and severity of lesions, location of lesions, and the preference of the child/parents. In general, physical destruction of the lesion, in particular, cryotherapy with liquid nitrogen and chemical destruction with cantharidin are the methods of choice for the majority of patients.

The molluscum contagiosum virus death effector domain containing protein MC160 RxDL motifs are not required for its known viral immune evasion functions.

The molluscum contagiosum virus (MCV) uses a variety of immune evasion strategies to antagonize host immune responses. Two MCV proteins, MC159 and MC160, contain tandem death effector domains (DEDs). They are reported to inhibit innate immune signaling events such as NF-κB and IRF3 activation, and apoptosis. The RxDL motif of MC159 is required for inhibition of both apoptosis and NF-κB activation. However, the role of the conserved RxDL motif in the MC160 DEDs remained unknown. To answer this question, we performed alanine mutations to neutralize the arginine and aspartate residues present in the MC160 RxDL in both DED1 and DED2. These mutations were further modeled against the structure of the MC159 protein. Surprisingly, the RxDL motif was not required for MC160's ability to inhibit MAVS-induced IFNß activation. Further, unlike previous results with the MC159 protein, mutations within the RxDL motif of MC160 had no effect on the ability of MC160 to dampen TNF-α-induced NF-κB activation. Molecular modeling predictions revealed no overall changes to the structure in the MC160 protein when the amino acids of both RxDL motifs were mutated to alanine (DED1 = R67A D69A; DED2 = R160A D162A). Taken together, our results demonstrate that the RxDL motifs present in the MC160 DEDs are not required for known functions of the viral protein.

An update on the clinical management of cutaneous molluscum contagiosum.

Molluscum contagiosum is a poxvirus infection of the skin that is commonly observed in children. The molluscum contagiosum virus (MCV) expresses several gene-products that are involved in its pathogenesis and evasion of the host immune system. MCV can be transmitted both to other sites of the body and to other individuals through direct physical contact as well as fomites. While diagnosis is generally straightforward clinically, management of molluscum contagiosum is controversial. Several treatment options are available for the destruction of individual lesions, but there is insufficient evidence for therapeutic intervention being any more effective than natural, spontaneous resolution. Complex cases, such as infection occurring in immunocompromised patients and in mucocutaneous sites, require an alternative approach to management. Molluscum contagiosum continues to represent a burden on children and parents worldwide.

Atypical molluscum contagiosum accompanied by CD30-positive lymphoid infiltrates.

Atypical presentations of molluscum contagiosum require histophathologic examination and may show pleomorphic lymphocytic infiltrates of a reactive nature, mimicking cutaneous lymphoproliferative diseases. Serial sections of specimens or polymerase chain reactions to show T-cell receptor clonality may be helpful for differential diagnosis. We report a case of atypical molluscum contagiosum accompanied by atypical lymphocytic infiltration showing CD30 positivity.

[The surface anesthesia in outpatient pediatric department].

The combination of even parts lidocaine and prilocaine in crème substance was used for surface anesthesia in 73 children, aged 1,5-16 years. Such surgical interventions as molluscum contagiosum eradication, laser wart resection and prepuce synechia dissection were performed. The described anesthetic was highly effective in all areas, but the nasolabial triangle. Resection of warts larger then 0,5 sm required either additional infiltrative anesthesia or step-wise resection. Local allergic reaction was registered in one case, no systemic reactions were noticed. Generally, the used method of surface anesthesia proved to be highly appropriate in pediatric practice.

Molusco contagioso: estudio descriptivo / Molluscum contagiosum: descriptive study

Introducción: El molusco contagioso (MC) es una infección cutánea viral causa frecuente de consulta. El objetivo de este estudio es evaluar los casos vistos en nuestro Servicio, analizar los datos epidemiológicos y el tratamiento pautado. Pacientes y método: Estudio descriptivo, entre el 16 de junio de 2008 y el 15 de enero de 2009, de los pacientes que acudieron con MC al Servicio de Dermatología del Complejo Hospitalario Arquitecto Marcide-Novoa Santos, Ferrol, España. En cada caso se recogieron los siguientes datos: sexo, edad, atopia, asistencia a piscina, número de lesiones y tratamiento. Resultados: Se seleccionó a 140 pacientes con MC. La edad media fue de 10,7 años. El 51,43% de los pacientes presentaba atopia y el 72,1% acudía a la piscina. La media del número de lesiones fue de 13,3, mayor en varones, pacientes con atopia y usuarios de piscina. El tratamiento consistió en legrado en el 86,4% de los casos. Conclusiones: Los niños con dermatitis atópica y los que acuden a piscina presentan MC con más frecuencia y en mayor número. Aunque la opción terapéutica es individualizada en función del paciente y las capacidades del médico, el legrado es la más empleada (AU)

Introduction: Molluscum contagiosum is a cutaneous viral infection that often requires assistance. The aim of our study is to review the cases admitted in our clinic, evaluate the epidemiological features and the treatment prescribed. Patients and methods: We conducted a descriptive survey of the patients diagnosed of molluscum contagiosum in our clinic (Complexo Hospitalario Arquitecto Marcide-Novoa Santos, Ferrol, Spain) between June 16th 2008 and January 15th 2009. The following dates were recorded in all cases: age, sex, personal history of atopy, swimming pool attendance, number of lesions and treatment prescribed. Results: 140 cases of molluscum contagiosum were included in the study. Average age was 10.7 years. 51.43% of patients had a personal history of atopy and 72.1% used to attendance swimming-pool. Average number of lesions was 13.3, with a higher number of them in males, atopic and swimming-pool attendants. Curettage was the treatment performed in 86.4% of cases. Conclusions: Atopic dermatitis and swimming-pool attendance were associated in our study with a higher frequency and number of molluscum contagiosum. Although different therapeutic options must be evaluated depending on the patient and clinical skills, curettage is the most frequent treatment performed by dermatologists (AU)

Molluscum Contagiosum / Molluscum Contagiosum

El Molluscum contagiosum es una infección viral benigna, causada por un poxvirus, que afecta habitualmente a niños entre 2 y 5 años con tasas de incidencia de entre el 5 y el 8%. Afecta también a individuos adultos sexualmente activos y los pacientes con infección por VIH presentan especial predisposición a esta infección. Generalmente las lesiones son autolimitadas y, aunque se han empleado numerosos tratamientos, no se ha demostrado que ninguna intervención sea más eficaz, por lo que se plantea el debate sobre si las lesiones del molusco contagioso deben ser tratadas o dejar que se resuelvan espontáneamente. Presentamos el caso de un adulto de 21 años con lesiones características y describimos brevemente el diagnóstico y tratamiento de esta infección (AU)

The Molluscum contagiosum is a benign viral infection. It is caused by a poxvirus and usually affects children from 2 to 5 years. The incidence rate is 5-8%. Also affects sexually active adults. Patients with HIV infection presents special predisposition to this infection. Skin lesions are usually self-limited. Although many treatments have been used, no treatment has been proved be more effective than the other. It is unknown whether the skin lesions should be treated or not. We present the case of an adult of 21 years old with characteristic lesions and we brief y describe the diagnosis and treatment of this infection (AU)

An overview of molluscum contagiosum: a viral skin condition.

Molluscum contagiosum is a virus that causes characteristic pearly lesions on the surface of the skin. Small clusters of mollusca are a nuisance rather than a serious health problem. However, the mollusca can be more widespread and disfiguring in people with impaired cell-mediated immunity. Molluscum contagiosum virus is common in children. In adults it can also be contracted during sexual activity and might indicate a need for diagnostic testing for other, more serious sexually transmitted infections in young, sexually active adults.

Molluscum contagiosum prevents progression of staphylococcal scalded skin syndrome.

Prevention of progression of staphylococcal scalded skin syndrome by molluscum contagiosum indicated a possible interference by viral anti-cytokine molecule such as interleukin-18 binding protein.

Evolution of HIV-1-related conjunctival molluscum contagiosum under HAART: report of a bilaterally manifesting case and literature review.

PURPOSE: To present a rare case of bilateral conjunctival molluscum contagiosum (MC) in an HIV-positive individual who had unilateral lesion excision before induction of highly active antiretroviral therapy (HAART), and to discuss the pathophysiological consequences of immune restoration. CASE REPORT: A 40-year-old male Caucasian presented with atypical, bilateral lesions of the limbal conjunctiva due to MC. Before the induction of HAART, nodules in the left eye were excised whilst the single lesion in the right eye was left untouched. RESULTS: The clinical diagnosis of conjunctival MC was confirmed histopathologically. Six months after the induction of HAART, the untouched lesion (right eye) had regressed and there was pronounced local injection of the conjunctiva. MC lesions did not recur after excision (left eye), and signs of inflammation were absent. CONCLUSION: Conjunctival MC is rare and associated with immune deficiency. To the best of our knowledge, the presented case is the first reported instance of bilateral, multi-lesional MC of the conjunctiva in an HIV-positive patient undergoing HAART. Attention must be paid to the possible complications associated with the restoration of immunocompetence.

Molluscum contagiosum.

In this article, the natural history of molluscum contagiosum is described by various authorities covering the last 200 years. Molluscum contagiosum may present a therapeutic challenge, but clinical methods of treatment are described. Molluscum contagiosum should alert the clinician to the possibility of HIV infection. The differential diagnosis in HIV infection is discussed.

Lesiones moluscoides en pacientes con SIDA / Molluscoid lesions in AIDS patients

Se presentan nueve pacientes HIV (+) con lesiones moluscoides debidas a molusco contagioso en cinco casos, histoplasmosis en tres casos y criptococosis en un caso. Ocho de estos pacientes se encontraban en un estadio avanzado de su enfermedad de base (C3) y el caso restante cursaba un estadio inicial (CI). Se realiza una breve revisión del tema y se enfatiza la importancia del diagnóstico precoz (por medio del estudio histopatológico y micológico) ya que pueden ser una manifestación temprana de enfermedades sistemáticas

Lesiones moluscoides en pacientes con SIDA / Molluscoid lesions in AIDS patients

Se presentan nueve pacientes HIV (+) con lesiones moluscoides debidas a molusco contagioso en cinco casos, histoplasmosis en tres casos y criptococosis en un caso. Ocho de estos pacientes se encontraban en un estadio avanzado de su enfermedad de base (C3) y el caso restante cursaba un estadio inicial (CI). Se realiza una breve revisión del tema y se enfatiza la importancia del diagnóstico precoz (por medio del estudio histopatológico y micológico) ya que pueden ser una manifestación temprana de enfermedades sistemáticas (AU)

Common ocular infections. A prescriber's guide.

While most ocular infections are benign, others can be associated with devastating visual consequences. Most patients present with either ocular discharge, visual symptoms or a red or painful eye. The primary care physician is usually the first to evaluate these patients. We have separated ocular infections into 3 groups. Infections affecting the cornea and conjunctiva often present with eye pain and a red eye; noninfectious aetiologies can have a similar presentation. Infections inside the eye (endophthalmitis) often have devastating consequences. They usually occur following penetrating ocular trauma or after intraocular surgery. Prompt referral to an ophthalmologist is crucial. Infections in the soft tissue surrounding the eye (ocular adnexa and orbit) can involve the eye indirectly and can spread from the orbit into the brain. The purpose of this article is to review ocular infections and current opinion regarding treatment. A general guideline should be that the approach to treatment be governed by the severity of symptoms and the magnitude of possible consequences. Mild external infections can be typically treated empirically. Severe conjunctivitis, and any corneal infection, require aggressive management, often including cultures and broad spectrum antibiotics; cultures are often used to guide treatment. Devastating vision loss can occur, even with aggressive management. Preseptal cellulitis in adults and older children can be managed conservatively with oral antibiotics if the orbit and optic nerve are not involved and the patient is otherwise healthy. Orbital or optic nerve involvement, on the other hand, demands orbital imaging and more aggressive intervention. Patients who have had recent surgery are at risk for developing endophthalmitis. Complaints of pain or a red eye must be taken very seriously. These patients must be considered to have an intraocular infection until it can be ruled out, and should be aggressively managed by a physician trained in eye diseases and surgery.

[Common virus infections of the skin. Molluscum contagiosum, herpes zoster, herpes simplex, condylomata acuminata, verrucae vulgares]. / Häufige Virus-Erkrankungen der Haut. Molluscum contagiosum-Herpes Zoster-Herpes simplex-Condylomata acuminata-Verrucae vulagres

The clinical diagnosis, etiology and predisposing factors of these common viral skin diseases are discussed with special emphasis on new therapeutic approaches.