Common Skin Conditions in Children: Skin Infections.

Skin infections account for a significant subset of dermatologic conditions of childhood. Common cutaneous viral infections in children include warts, molluscum contagiosum, hand-foot-and-mouth disease, and herpes simplex. Although viral infections are self-limited and often only mildly symptomatic, they can cause anxiety, embarrassment, and health care use. Recognition of their common and atypical presentations is necessary to differentiate them from other skin conditions of similar morphology. Impetigo, cellulitis, and abscess comprise the majority of childhood bacterial skin infections and are treated with topical or systemic antibiotics that cover group A Streptococcus and Staphylococcus aureus. Common fungal dermatologic infections in children are oral and genital candidiasis, tinea capitis, and tinea corporis. Management consists of topical and systemic antifungals, including nystatin, triazoles, terbinafine, griseofulvin, and imidazoles. Scabies is the most common parasitic skin infection among children and is managed with topical permethrin. Although serious illness is not common among children returning from international travel, patients presenting with fever and rash, especially petechial or hemorrhagic lesions, require thorough evaluation. Of the numerous reportable conditions that present with childhood rash, tick-borne illnesses, measles, rubella, and varicella are the most common.

Parasitic Diseases With Cutaneous Manifestations.

Parasitic diseases result in a significant global health burden. While often thought to be isolated to returning travelers, parasitic diseases can also be acquired locally in the United States. Therefore, clinicians must be aware of the cutaneous manifestations of parasitic diseases to allow for prompt recognition, effective management, and subsequent mitigation of complications. This commentary also reviews pharmacologic treatment options for several common diseases.

Sensations of skin infestation linked to abnormal frontolimbic brain reactivity and differences in self-representation.

Some patients experience skin sensations of infestation and contamination that are elusive to proximate dermatological explanation. We undertook a functional magnetic resonance imaging study of the brain to demonstrate, for the first time, that central processing of infestation-relevant stimuli is altered in patients with such abnormal skin sensations. We show differences in neural activity within amygdala, insula, middle temporal lobe and frontal cortices. Patients also demonstrated altered measures of self-representation, with poorer sensitivity to internal bodily (interoceptive) signals and greater susceptibility to take on an illusion of body ownership: the rubber hand illusion. Together, these findings highlight a potential model for the maintenance of abnormal skin sensations, encompassing heightened threat processing within amygdala, increased salience of skin representations within insula and compromised prefrontal capacity for self-regulation and appraisal.

Tropical and exotic dermatoses and ulcers.

BACKGROUND: Tropical dermatoses and ulcers, although essentially unique to tropical and subtropical areas, are occasionally seen in Australian general practice on returning travellers and migrants from endemic countries. OBJECTIVE: This article will discuss important causes of tropical and exotic ulcers occasionally seen in Australia. DISCUSSION: As tropical ulcers may mimic many other causes of skin ulceration and nodules, a history of recent travel should arouse clinical suspicion. The time frame since exposure to the causative organism is an important feature in the diagnostic process. For example, pyodermas and cutaneous larva migrans present a few days after contact with the causative agents, whereas leishmaniasis, cutaneous tuberculosis, atypical mycobacterial diseases (swimming pool granulomas) and tropical mycosis take weeks to months to appear.

Skin lesions, malaise, and heart failure in a renal transplant recipient.

A male Caucasian patient developed nodular erythematous skin lesions, malaise, and clinical signs of progressive heart failure 4 months after renal transplantation. Bronchoscopy with bronchoalveolar lavage performed for a small infiltrate seen on a computed tomography scan revealed Trypanosoma, which had at this point not been suspected as a cause. Parasitemia was present, and reactivation rather than transmission of Chagas' disease was established by performing polymerase chain reaction and serology in the donor and recipient. Treatment with benznidazole and allopurinol successfully reduced parasitemia, but the clinical course was fatal owing to progression of severe myocarditis. The patient had never lived in an endemic area, but had an extensive travel history in South America. The last visit was more than 5 years before transplantation. In non-endemic countries (United States, Europe), reactivation after transplantation has only been very rarely reported. Given the rising numbers of transplantations in patients with a migration background and extensive travel histories, specific screening procedures have to be considered.

Filariasis presenting as multiple subcutaneous nodules: a rare case report.

Filariasis presenting as multiple subcutaneous nodules is very rare and only a very few cases are reported in the literature. Microfilaria bancrofti is known to occur in different sites like breast, thyroid, lymph nodes, liver, lungs and body fluids, however, in contrast to the other filarial species, its occurrence in soft tissues is rarely reported. Conventional method of diagnosis of filariasis is by demonstration of microfilaria in peripheral blood smear which may be diurnal or nocturnal. The various species are differentiated by the morphological features like presence or absence of sheath, granules and nuclear arrangement in the tail end. We hereby report an unusual case of Wuchereria bancrofti infestation diagnosed on biopsy of subcutaneous nodule in a patient whose initial clinical presentation was of urticarial rashes over the upper extremities. In differential diagnosis of various subcutaneous nodular masses the possibility of filarial granuloma must be kept and a careful search should be done for adult worm or microfilaria in the serial tissue sections.

Eudiplozoon nipponicum in focus: monogenean exhibiting a highly specialized adaptation for ectoparasitic lifestyle.

Developmental stages of the diplozoid monogenean Eudiplozoon nipponicum, comprising oncomiracidium, diporpa, juvenile, and adult, were investigated using light and scanning electron microscopy in conjunction with confocal scanning laser microscopy in order to examine body organization and identify explicit morphological adaptations to the ectoparasitic life in each stage. The parasite exhibits a complex digestive tract well equipped for hematophagous feeding. It consists of a mouth opening with prominent buccal suckers, eversible pharynx with adjacent glandular structures, and a blind-ending gut with cecal lining. Glandulo-muscular organs, located apically and opened into the mouth corner, are considered to be a part of the digestive tract. Based on our observations of pharynx eversion and in light of the presence of several glandular or gland-like structures, we propose a new hypothesis on the possibility of extracorporeal digestion of this parasite. The hindbody bears an attachment apparatus, comprising haptor, lobular extensions, and tegumental folds, responsible for the parasite's firm attachment to the host gills. The possibility of buccal suckers assisting in the parasite's translocation while searching for an optimal niche or their temporary attachment function during feeding is discussed. The body of each compound adult (i.e., permanent copula) is almost completely filled by two complete reproductive tracts comprising the female as well as male organs. Such a reproductive strategy, in which two independent heterogenic individuals fuse into a single hermaphrodite organism without the need to search for mating partner, represents a high specialization of diplozoids to their parasitic life.

Short report: case of gnathostomiasis in Beijing, China.

A 59-year-old woman sought treatment of for creeping eruption and erythematous plaques associated with high fever and systemic symptoms. She had a history of eating undercooked freshwater fish raised in Beijing 10 days before admission and reported no travel during the previous year. Blood examination showed eosinophila and ultrasonography detected multiple hypoechoic areas in the liver and spleen. Western blot test detected specific antibodies to the larvae of Gnathostoma spinigerum. Cutaneous and visceral larva migrations associated with G. spinigerum were diagnosed. Twenty-three cases in 12 provinces have been reported in the Chinese literature but none have been reported in English.

Interferon (IFN)-gamma , tumor necrosis factor-alpha , interleukin-6, and IFN-gamma receptor 1 are the major immunological determinants associated with post-kala azar dermal leishmaniasis.

Semiquantitative reverse-transcription polymerase chain reaction was used to analyze intralesional cytokine gene expression in 28 patients with post-kala azar dermal leishmaniasis (PKDL) and 14 patients with kala azar (KA). The data revealed mixed T helper cell type 1 (Th1) and T helper cell type 2 (Th2) responses, as reflected by elevated expression of interferon (IFN)-gamma , tumor necrosis factor (TNF)-alpha , transforming growth factor (TGF)-beta , interleukin (IL)-10, IL-6, and IL-4 mRNA, with minimal expression of IFN-gamma receptor 1 (IFN-gamma R1) mRNA in PKDL lesions, compared with that in normal skin tissue. In comparison with those in KA lesions, mRNA levels for IFN-gamma , TNF-alpha , and IL-6 were found to be significantly elevated in PKDL lesions, implying that these cytokines play an important role in PKDL pathogenesis. In the presence of elevated levels of IFN-gamma and TNF-alpha , interference with type 1 effector activity in PKDL may be due to minimal expression of the IFN-gamma R1 gene or the simultaneous presence of elevated levels of IL-10, IL-6, and TGF-beta , which have counteracting effects. After treatment, the restoration of IFN-gamma R1 at both mRNA and protein levels, coupled with down-regulation of counteracting cytokines, may facilitate the action of signals associated with IFN-gamma , yielding parasite clearance. Therefore, unfavorable clinical evolution in PKDL may not be due to the absence of an intralesional Th1 response but rather may be due to the presence of counteracting cytokines along with the down-modulation of IFN-gamma R1.

Nódulo eritematoso en el dorso de la mano / Erythematous nodule on the back of the hand

No disponible

Ivermectin in dermatology.

Ivermectin, a broad-spectrum anti-parasitic agent first used in veterinary medicine, is active against numerous species of helminths and arthropods. For the past few years, world-wide reports on the use of ivermectin in various parasitic diseases with cutaneous tropism have led to its use in the field of skin parasitology. In this paper we review parasitoses which have been treated with ivermectin; mainly, filariasis, strongyloidiasis, cutaneous larva migrans, and scabies and head lice.

Myiasis.

Myiasis is not an uncommon parasitic infestation in the tropics and subtropics, and with the increase in international travel, cases also are encountered outside the endemic regions in both Europe and North America. This article reviews the ecology, classification, pathophysiology, pathology, and treatment of myiasis.

Infection of BALB/c, C57Bl/6 mice and F1 hybrid CB6F1 mice with strains of leishmania mexicana isolated from Mexican patients with localized or diffuse cutaneous leishmaniasis

Mice from the syngeneic strains BALB/c, C57Bl/6 and (BALB/cxC57Bl/6) F1 hybrids (CB6F1) were infected in the fottpad with six different stains of Leishmania mexicana mexicana isolated from Mexican patients. Three Leishmania strains were isolated from patients with localized cutaneous leishmaniasis (LCL, the benign form of the disease and three from patients with diffuse cutaneous leishmaniasis (DCL, the malignant form of the disease). In BALB/c mice, four Leishmania strains showed a sustained fast growth from 4 to 5 weeks postinfection until the end of the experiment (15 weeks), and the other two grew slowly up to 10 or 12 weeks after infection and then started to grow faster. In C57Bl/6 mice four Leismania strains showed a limited to moderate growth up to 6 to 11 weeks postinfection and then started to decrease. One strain showed a moderate growth during the entire experiment and one strain grew as fast as in BLB/c mice up to 11 weeks postinfection and then started to decrease. The CB6F1 hybrid behaved like the C57Bl/6 parent strain with five Leishmania strains but was much more resistant to one Leishmania strain than the C57Bl/6 mice. Sex of the mouse did not influence the outcome of infection. One important purpose of this work was to see if the Leishmania strains that cause DCL are intrinsically more virulent than those that cause the benign form (LCL). Although important variations in virulence among the Leishmania strains were observed, especially in BALB/c mice, they were not correlated with the type of disease caused in humans

Tratamiento de la escabiasis con ivermectina por vía oral / Treatment of scabiasis with oral ivirmectina

Se reporta un estudio clínico, doble ciego, controlado, para evaluar la eficacia y seguridad de ivermectina por vía bucal a la dosis de 200 mcg/kg de peso para el tratamiento de la escabiasis, efectuado en 55 pacientes. Los resultados informaron que 26 pacientes (79.3 por ciento) curaron con ivermectina en su primera visita de control, en comparación con cuatro (16 por ciento) del grupo que recibió placebó (X²= 77.07, p<0.001). Al final 37 pacientes de 50 (74 por ciento tratados con ivermectina curaron comparados con cuatro de 26 (16 por ciento) manejados con placebo. Esta diferencia es significativa (X²=23.66, p<0.001). Se concluyó que la ivermectina por vía oral efectiva y segura en el tratamiento de la escabiasis

[Intestinal parasitosis: physiopathologic aspects]. / Parasitosis intestinal: aspectos fisiopatológicos.

The variety of pathological changes that occur during parasitic infections is diverse. Recently there has been done considerable progress in understanding the physiopathologic aspects of the direct parasitic action of the products that they release, that affect the digestive function. The pathogenetic effects of intestinal parasites are important, not only for the adult forms that occupy the lumen or the intestinal mucosa, but for the migratory forms. The most important clinical manifestations are in direct relation with the host response to the aggression or trauma caused by the migratory larvae and/or adults parasites, the signs and symptoms depends on the infestation phase and on the severity or in the agent "virulence". The objective of this article is to present a brief revision on the physiopathologic effects of infestations by intestinal parasites.

Dermatitis en humanos producida por Paederus Irritans Chapin, 1926 (Coleoptera, Staphylinidae) / Human dermatitis by Paederus Irritans Chapin, 1926 (Coleoptera, Staphylinidae)

Por primera vez en el país se producen lesiones cutáneas en voluntarios de Lima sometiéndoles a la acción tóxica de Paederus Irritans; la toxina se encuentra en la hemolinfa del insecto, la que se vierte a la superficie al ser frotado sobre la piel. Las lesiones se inician entre las 24 y 48 horas. Clínicamente se aprecia eritema, edema, pápula con vesículas de color amarillo con contenido necrótico de lenta cicatrización; los síntomas son: prurito intenso, dolor, en algunas personas fiebre y malestar general recuperándose totalmente después de 20, 30 a 35 días. La toxina se mantiene activa en el insecto hasta después de varios meses de muerto

Infectious diseases of the skin.

Pathologic changes in the skin of elderly individuals increase their susceptibility to skin infections. These changes include thinning, decreased secretions, and reduced immune function. This paper will discuss the most important viral, fungal, bacteriologic, and parasitic infections of the skin in the elderly and the appropriate treatment of these infections.

[A case of skin myiasis caused by Dermatobia hominis]. / Ein Fall von Hautmyiasis durch Dermatobia hominis.

A case of erysipelas-like symptoms in a 26-year-old female student of medicine having returned from Nicaragua to Germany is reported. On the removal of the scurf covering the supposed entrance of the erysipelas, a larva of Dermatobia hominis, the human bot fly, was extracted from the head skin, and the inflammation completely disappeared within a short period of time.