Biomedical subjects

Roberto Arenas

Publications and source records attributed to Roberto Arenas.

11 recordsLinked to original sources

PubMed2006

Sporothrix schenckii type 3D (mtDNA-RFLP): report of an osteoarticular case.

Sporotrichosis is a frequent subcutaneous mycosis in Mexico and lymphocutaneous cases are the most common type. Extracutaneous or disseminated forms are exceptional and are usually seen in immunosuppressed hosts. We report the case of a 74-year-old immunocompetent male with osteoarticular involvement. The isolated Sporothrix schenckii was classified as type 3D according to restriction fragment length polymorphism analysis of the mitochondrial DNA (mtDNA-RFLP).

Aged↗

PubMed2006

Kerion and dermatophytic granuloma. Mycological and histopathological findings in 19 children with inflammatory tinea capitis of the scalp.

BACKGROUND: Inflammatory tinea capitis or kerion is the result of a hypersensitivity reaction to a dermatophytic infection. Majocchi's granuloma, in contrast, usually begins as a suppurative folliculitis and culminates in a granulomatous reaction. OBJECTIVES: To present clinical, mycological and histopathological findings for 19 cases of kerion of the scalp in children. METHODS: Nineteen children were investigated (14 boys and five girls) with a mean age of 6.5 years. A potassium hydroxide (KOH) exam and culture in Sabouraud dextrose agar were performed, followed by a biopsy with hematoxylin and eosin, periodic acid-schiff (PAS) and Gomori-Grocott stains. The same investigations were carried out in four control cases of noninflammatory tinea capitis. RESULTS: Clinical history varied from 2 to 16 weeks (mean 6.6 weeks). Diagnosis was confirmed by a positive KOH exam: all cases except one had a positive culture. The following dermatophytes were isolated: Microsporum canis (32%), Trichophyton mentagrophytes (27%), Trichophyton tonsurans (21%), Trichophyton rubrum (10%) and Microsporum gypseum (5%). The histopathological findings were: suppurative folliculitis (SF) 11%, SF plus suppurative dermatitis 37%, suppurative and granulomatous dermatitis (SGD) 26% and SGD plus fibrosing dermatitis 26%. Fungi were observed in 63% of the histopathological sections. Perifollicular infiltrates (PF) around the parasitized hair follicles were identified in the four noninflammatory control cases due to M. canis. CONCLUSIONS: Kerion Celsi is an inflammatory or suppurative type of tinea capitis caused by zoophylic dermatophytes (M. canis and T. mentagrophytes), but also by antrophophylic (T. tonsurans and T. rubrum) and geophylic (M. gypseum) dermatophytes. Histopathological findings showed a spectrum from mild suppurative folliculitis to dense granulomatous infiltrates without a clear relationship with the clinical features.

Biopsy↗

PubMed2006

[Vulvar syringoma: a report of two cases].

Syringoma is a benign neoplasm of eccrine origin. Lesions often arise around the eyes and on the upper cheeks of middle-aged women. Syringomas involving the genitalia are rare, they present as multiple, bilateral, skin-colored papules over the labia majora. The lesions should therefore be considered in the differential diagnosis of multiple papular lesions of the vulva. We report two females of 37 and 62 years of age, both observed in a dermatological service.

Adult↗

PubMed2005

[Primary cutaneous mucormycosis. Report of a case in a HIV patient].

Primary cutaneous mucormycosis is an unusual mycotic infection associated to immunosupression. We present a 34 year-old woman with HIV infection with a necrotic primary mucormycosis of the skin associated to a venous catheter. She was treated with amphotericin B and surgical debridement.

AIDS-Related Opportunistic Infections↗

PubMed2005

The value of Doppler ultrasound in diagnosis in 25 cases of furunculoid myiasis.

BACKGROUND: The larvae of the botfly Dermatobia hominis cause furunculoid myiasis in endemic areas. Lack of knowledge of this condition outside these areas leads to confusion in diagnosis and delays appropriate treatment. OBJECTIVE: To describe the clinical findings of furunculoid myiasis encountered in Quintana Roo, in the south-east of Mexico. MATERIALS AND METHODS: We performed an observational study on 25 cases diagnosed over a period of 4 years. RESULTS: Diagnosis of furunculoid myiasis was made in 14 males and 11 females with an average age of 24.5 years. Most of our patients were students, farmers, or housewives. The number of lesions varied from one to four. In 20% of cases, more than one parasite was present in each lesion. The scalp was the most commonly affected region (40%), followed by the trunk and the extremities. Doppler ultrasound study (DUSG) of the furuncle-like lesions confirmed the clinical diagnosis in all cases. CONCLUSIONS: Furunculoid myiasis is frequent in the state of Quintana Roo, Mexico. We found no association with occupation, gender, social background or age. DUSG can be used to evaluate the number of parasites per furunculoid lesion avoiding misdiagnoses and treatment delays.

Adolescent↗

PubMed2004

[Superficial infections caused by Microsporum canis in humans and animals].

Dermatophytic infections caused by M. canis in humans and animals have a world wide distribution and they are zoonotic. The objective in this work was to know the frequency of M. canis infections in humans and pets. We studied our cases from January 1994 to December 2002. The human samples were obtained from a Dermatological Department in a General Hospital and we registered the next data: age, sex, job, and affected area. The animal samples were obtained from a mycological veterinary laboratory, and we registered the presence or absence of clinical lesions. A total of 46 clinical cases of M. canis infections were recorded, 26 female and 20 males: tinea capitis 21, tinea corporis 17, tinea pedis five, onychomycosis two, and only one case with tinea faciei. The 46 cases with positive culture yield 42 positive samples in KOH. The age range varied from 2 to 60 years. Among the animals, we studied 461 dogs and found six KOH positive (1%) samples and cultured 23 isolates (4.98%): 21 M. canis, one M. gypseum and one Trichophyton spp. From the 68 samples of cats, eight (11.76%) were positive to KOH, being 26 (38.23%) M. canis isolates. In M. canis infections in humans, the age rage was wide with predominance in women. In animals, M. canis isolates represented the most dermatophytic infection.

Animals↗

PubMed2003

Pseudo-fibrokeratoma: an unusual presentation of subungual squamous cell carcinoma in a young girl.

An interesting case of subungueal squamous cell carcinoma in a 13-year-old girl is presented. The tumor presented as a pseudo-fibrokeratoma with melanonychia on the index finger. Biopsy was diagnostic and treatment consisted of Mohs micrographic surgery and secondary intention wound healing. This is one of the youngest patients ever reported with subungueal squamous cell carcinoma, and there is only one more case of pseudo-fibrokeratoma and melanonychia reported as initial skin lesions.

Adolescent↗

PubMed2002

[Dermatophytoses in Mexico].

The dermatophytic infections are superficial mycoses common in Mexico, they have an estimated frequency of 5% in dermatological outpatients. In this review we present a global view of these mycoses as well as their etiological agents in tinea capitis, tinea pedis, tinea corporis, tinea cruris and onychomycosis and also uncommon infections such as tinea imbricata and epidermophytosis of the diaper area. We also analyze these infections in diabetic patients, healthy carriers and dermatophytic infections in pets and laboratory animals. The most important publications about dermatophytosis in Mexico in the dermatological, epidemiological or mycological area are reviewed, specially those published in the last ten years.

English Abstract↗

PubMedDate not supplied

Superficial mycotic infections of the foot in a native pediatric population: a pathogenic role for Trichosporon cutaneum?

Superficial mycotic infections of the feet are usually caused by Tricophyton rubrum, predominantly affecting adults and resulting from the use of occlusive footwear. We carried out a mycologic study of superficial foot infections in a rural school in Mexico where most people wear a leather, nonocclusive sandal. Forty students had clinical signs of 50 fungal infections of the foot: 39 athlete's foot and 11 onychomycosis. Thirty-one boys and 9 girls were studied. Hyphae were seen in 11 cases of athlete's foot and 5 of onychomycosis. Twenty-one cultures were positive (42%). The most frequently isolated fungi were the opportunistic Trichosporon cutaneum in 42.8%, Candida sp. (23.8%), Trichophyton mentagrophytes (23.8%), and Candida glabrata (9.5%). Superficial mycotic infections of the feet and nails were most frequent in children and adolescents who usually wear nonocclusive shoes. The most frequent pathogens were Candida sp. and T. mentagrophytes. It is interesting to note the prevalence of T. cutaneum that has recently been implicated in mycoses of the feet and nails. We did not isolate T. rubrum in any patient.

Adolescent↗

PubMedDate not supplied

[Tinea pedis and Onychomycosis in Children of the Mazahua Indian Community in Mexico].

BACKGROUND: Tinea pedis and onychomycosis in childhood are unusual, The previous reported prevalence range from 4.2 to 8.2%. In a mestizo population, in the South of Mexico a 3.4% has been found. OBJECTIVE: To determine the frequency of dermatophytosis of feet and toenails in scholars in an Indian Mazahua community. METHODOLOGY: A total of 456 children were studied. The age range from 5 to 15 years of age (average 11.4). Only 71 children with suggestive lesions of dermatophytosis were studied (15.57%). Mycological samples (66/71) and a KOH and Chlorazol black, and cultures on Mycocel agar were performed. RESULTS: 71 children (15.57%) presented suggestive lesions of dermatophytosis of the feet and toenails. A fungal infection was demonstrated in 13 cases (18%), 8 males and 5 females (mean age 12.3 years), but pathogenic fungi were isolated only in 7 (10%). All of them with tinea pedis and three also had toenail involvement (4.2%) and also Trichosporon sp was isolated in two cases and Candida albicans in one. CONCLUSIONS: We found a low frequency of tinea pedis and onychomycosis in children from this Mazahua community. The environmental factors such as humidity, and the frequently use of rubber and leather shoes instead of the traditional "huarache" (sandals), make them prone to maceration and can be cofactors in the development of mycotic infections and in the high incidence of pitted keratolysis (29.5%).

Adolescent↗

PubMedDate not supplied

[Actinomycetoma and Nocardia sp. Report of five cases treated with imipenem or imipenem plus amikacin].

INTRODUCTION: Dapsone with trimethoprim-sulfamethoxazol is currently the standard treatment for actinomycetoma. In select cases, amikacin, streptomycin, kanamycin, amoxicillin/clavulanic acid or phosphomycin may be also added. Imipenem has shown to be effective both in vitro and in vivo against some actinomycetes. Amikacin with Imipenem has a synergistic effect. OBJECTIVES: To report our preliminary findings using imipenem alone or with amikacin for severe or multi-resistant mycetomas due to Nocardia sp. MATERIAL AND METHODS: We present 5 cases of chronic mycetoma infection previously treated with anti-bacterial multidrug regimens. All patients were hospitalized and treated with imipenem 500 mg IV, three times a day for three weeks. Three patients received in addition amikacin. RESULTS: We included 3 male and 2 female patients. The average length of disease duration was 7.4 years. In 3 cases mycetoma was located on the back; one of them involved the rib and the lung. One case was localized in the abdominal wall, and another one involved the posterior side of the cervical region. Two patients achieved clinical and bacteriological cure one year after treatment with Imipenem, and the remaining three displayed clinical improvement, even though grains were observed, cultures where negative. None of the 5 patients studied showed clinical evidence of adverse reactions to Imipenem. CONCLUSIONS: Imipenem is a strong antibiotic and constitutes an important treatment alternative for severe or multi-resistant mycetoma especially for cases with bone and visceral involvement.

Adult↗