Microsporum Sp Research Articles

Dermatology for the practicing allergist: Tinea pedis and its complications

Tinea pedis is a chronic fungal infection of the feet, very often observed in patients who are immuno-suppressed or have diabetes mellitus. The practicing allergist may be called upon to treat this disease for various reasons. Sometimes tinea infection may be mistaken for atopic dermatitis or allergic eczema. In other patients, tinea pedis may complicate allergy and asthma and may contribute to refractory atopic disease. Patients with recurrent cellulitis may be referred to the allergist/immunologist for an immune evaluation and discovered to have tinea pedis as a predisposing factor. From a molecular standpoint, superficial fungal infections may induce a type2 T helper cell response (Th2) that can aggravate atopy. Th2 cytokines may induce eosinophil recruitment and immunoglobulin E (IgE) class switching by B cells, thereby leading to exacerbation of atopic conditions. Three groups of fungal pathogens, referred to as dermatophytes, have been shown to cause tinea pedis: Trychophyton sp, Epidermophyton sp, and Microsporum sp. The disease manifests as a pruritic, erythematous, scaly eruption on the foot and depending on its location, three variants have been described: interdigital type, moccasin type, and vesiculobullous type. Tinea pedis may be associated with recurrent cellulitis, as the fungal pathogens provide a portal for bacterial invasion of subcutaneous tissues. In some cases of refractory asthma, treatment of the associated tinea pedis infection may induce remission in airway disease. Very often, protracted topical and/or oral antifungal agents are required to treat this often frustrating and morbid disease. An evaluation for underlying immuno-suppression or diabetes may be indicated in patients with refractory disease.

Ringworm in small exotic pets

Dermatophytes are fungi that can use keratin as a nutrient source. These organisms invade keratinized tissue (skin, hair, and nails) and cause dermatophytosis or ringworm. Colonization is usually restricted to the nonliving, cornified layer of the epidermis because of the inability of dermatophytes to penetrate viable tissue of an immunocompetent host. However, infection does elicit a host response ranging from mild to severe that is related to the species and strain of fungus. Zoophillic species are primarily parasitic on animals, and infections are often mild or symptomless in exotic pets. Infection with unusual or geophilic (soil-associated) dermatophytes causes severe inflammatory lesions. Ringworm has long been associated with rodents and rabbits: it is common in rabbits and guinea pigs; uncommon in chinchillas, mice, and rats; rare in golden and dwarf hamsters; and unreported in gerbils. Dermatophytosis is rare in ferrets and unreported in pet African pygmy hedgehogs. In naturally occurring infections, Trichophyton mentagrophytes is the fungal species most commonly isolated; Microsporum sp . are occasionally reported. Because dermatophytes cause a communicable disease, pets that are symptomless carriers represent a potential zoonotic source to their owners. Current methods of diagnosis and clinical management of dermatophytosis, including a survey of recent trends in therapy are presented.

Tineas—Superficial Dermatophyte Infections

Tineas—Superficial Dermatophyte Infections

Microbiota indígena do meato acústico externo de gatos hígidos

Cinqüenta felinos hígidos, adultos - vinte e seis machos e vinte e quatro fêmeas - sem definição racial, com distintas idades, reunidos em dois grupos (GRUPO 1- animais domiciliados e GRUPO 2 - animais que rendados) de vinte e cinco animais cada. Após anamnese e prévia sedação, os gatos foram submetidos a exame físico e à otoscopia, comprovando-se a ausência de lesões meatais e timpânicas, com cureta de Buck e wragatoas estéreis, foi colhido material meatal, que foi então submetido a exames bacteriológico e micológico. No Grupo 1, foi evidenciado presença de Otodectes cynotis (4% das amostras), em 72% dos casos de bolores e leveduras (Cladosporium sp 66,6%, Malassezia sp 40%, Penicillium sp 33%, Aspergillus sp 33,3%, Rhodotorula sp 20,0%, Mycelia sp 13,3% e Alternaria sp, Aureobasidium sp, Ryzopus sp, Trichosporon sp, todos com 6,6%) e, finalmente, em 64% da amostragem, bactérias dos gêneros Staphylococcus spp (81,2%), Pseudomonas sp (12,5%), Klebsiella sp (12,5%), Acinetobacter sp, Bacilos difteróides, Enterobacter sp, Lactobacillus spp (todos com 6,2%). No Grupo 2, o Otodectes sp foi identificado em 36% das amostras, em 96% daquelas isolaram-se fungos dos gêneros: Malassezia sp - 54,1%, Aspergillus e Penicillium sp, ambos com 33,3%, Microsporum sp - 29,1%, Cladosporium sp - 16,6%, Trichoderma sp - 12,5%, Alternaria e Phoma sp, ambos com 8,3% e Epicoccum sp, Neurospora sp. Mycelia sp, Rhodotorula sp, todos com 4,1% e, por fim, em 20 das 25 amostras (80%) isolaram-se pelo menos uma cepa bacteriana (Staphylococcus spp 75%, Klebsiella sp 20,8%, Bacilos difteróides 12,5%, Pseudomonas sp, 8,3%) e Acinetobacter sp, Enterobacter sp e Escherichia sp, todos com 4,1% cada um em cultivo monoespecífico ou em associação.

Infectious Alopecia in a Child Day-Care Center

To the Editor.— Tinea capitis is a common cause of hair loss and seborrheic dermatitis in children. Recent reports have suggested an increase in the rate of recognition of tinea capitis, as well as a shift from the previously more common etiologic agent Microsporum sp to the now prominent Trichophyton tonsurans . 1 This change in causative agents is important in that Microsporum sp is transmitted primarily from animal to man with frequent spontaneous resolution in humans while Trichophyton is transmitted person to person and infection may follow a chronic course without appropriate therapy. In view of these considerations and the growing number of children in day-care centers, it should be expected that the association of tinea capitis and day-care attendance will merit more attention. Report of a Case.— A Birmingham, Ala, child day-care center having an enrollment of 78 children aged 1 to 4 years reported that five children developed

Drug therapy reviews: Clinical pharmacology and therapeutic use of antimycotic drugs

Indications, pharmacology, mechanism of action, adverse reactions, administration and dosage ot SIX antimycotic drugs (amphotericin B, flucytosine, nystatin, clotrimazole, miconazole nitrate and griseofulvin) are reviewed. The availability and cost of commercial preparations are listed. Amphotericin B is the single most effective drug against the following systemic fungal infections: blastomycosis, histoplasmosis, cryptococcosis, candidiasis, sporotrichosis, aspergillosis, mucormycosis and coccidioidomycosis. Some Candida sp are sensitive to flucytosine, but the drug IS useful only occasionally in the treatment of systemic candidal infections. Flucytosine may be effective in the treatment of Aspergillus pneumonia and meningitis, hut this drug alone is not the best treatment. Nystatin has been used topically to treat superficial candidal infections of the oral mucosa (thrush) and esophagus, and candidal stomatitis, pharyngitis and vaginitis; aerosols have been used to treat systemic aspergillosis and candidiasis. Clotrimazole. IS useful topically for Candida, Tricophyton or Microsporum skin infections, and vaginally tor vaginal candidiasis. Intravenous miconazole is used most commonly against Coccidioides immitis infections involving pulmonary, osseous and meningeal sites; topically, miconazole has the same Uses as clotrimazole. Griseofulvin is most effective for tinea and ringworm infections caused by Tricophyton sp and Microsporum sp. No other antiinfective drug causes toxic reactions as often as amphotericin B; however, the drug does have unique uses that often outweigh its risks. Flucytosine may depress the bone marrow and cause leukopenia, neutropenia and thrombocytopenia. Nystatin causes few adverse reactions; systemic absorption is minimal. There are few side effects with topical use of Clotimazole. Phlebitits often occurs after i.v administration of miconazole nitrate. Griseofulvin produces few adverse effects