Tinea versicolor andPityrosporum orbiculare:A mycological investigation

Abstract

It has generally been accepted that the cause of tinea versicolor is the dimorphic lipophilic fungus Pilyrosporum orbiculare. In this investigation the fungus was cultured from all patients with tinea versicolor. It was also isolated from normal-looking skin and apparently healed lesions in a high proportion of patients with tinea versicolor; from patients with seborrheic dermatitis, and from healthy volunteers.Isolation of P. orbiculare was most satisfactorily achieved on a peptone-glucose-yeast extract medium containing glycerol monostearate, overlaid with olive oil. Germ tubes were produced when P. orbiculare was incubated in an atmosphere containing air with 7 % CO 2. Cultures of P. orbiculare and P. ovale did not show fluorescence in Wood's light.

Skin diseases associated with Malassezia species

“…These may include malnutrition, 62 use of oral contraceptives, 63 use of systemic corticosteroids or immunosuppressants, and hyperhidrosis. 64,65 Pityriasis versicolor is diagnosed on the basis of its clinical appearance and the diagnosis can be confirmed by microscopy. Clinically, pityriasis versicolor can resemble other dermatologic disorders, and differential diagnosis should include vitiligo (particularly in patients with dark skin and hypopigmented lesions), tinea corporis (in this instance, the causative organism is a dermatophyte rather than a yeast as in pityriasis versicolor), SD, pityriasis rosea, pityriasis alba, chloasma, erythrasma, confluent and reticulated papillomatosis of Gougerot and Carteaud, pityriasis rotunda, 66-68 secondary syphilis, and pinta.…”

Pitiríase Versicolor

“…Experimentalmente a infecção tem sido induzida por roupas oclusivas. 30 Por outro lado, fatores endó-genos [31][32][33] são responsáveis pela prevalência da doença em climas temperados, e neles incluem-se a dermatite seborréica, a síndrome de Cushing, o tratamento com imunossupressor, a desnutrição e a hiperidrose (particularmente flexural). Fatores hereditários parecem desempenhar algum papel na doença.…”

Efficacy of triclosan soap against superficial dermatomycoses: a double‐blind clinical trial in 224 primary school‐children in Kilombero District, Morogoro Region, Tanzania

“…With regard to tinea versicolor, the growth of lipophilic Malassezia spp., which is usually enhanced by the amount of endogenous lipids 22,23 or the application of oily substances, 24–26 may have been reduced by soap use. In addition, the degree of occlusion of the skin by excessive amounts of lipids, affecting the carbon dioxide concentration and pH range, is likely to have decreased 27–29 . The use of keratolytic soaps has been recommended for the mechanical removal of infected scales 30 .…”