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Infections Due to Malassezia

Infections Due to Malassezia. Presenter: Dr. Cooper. Definition. Various species of Malassezia cause both opportunistic, superficial infections and occasionally systemic infections Common superficial infections include: Pityriasis versicolor Seborrheic dermatitis Atopic dermatitis

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Infections Due to Malassezia

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  1. Infections Due to Malassezia Presenter: Dr. Cooper

  2. Definition • Various species of Malassezia cause both opportunistic, superficial infections and occasionally systemic infections • Common superficial infections include: • Pityriasis versicolor • Seborrheic dermatitis • Atopic dermatitis • Folliculitis • Dandruff

  3. Case Report 1 • Fan et al., Arch. Dermatol. (2006) 142: 1181-1184. • In January 2004, a 49 year-old female developed an asymptomatic facial papule • Self-treated with herbs, but became larger, erosive, and produced an exudate

  4. Case Report 1 (cont.) • In March 2004, a similar nasal lesion appeared • Patient presented to clinic in April 2004 • No history of trauma • Owned a pet dog for 9 months • No lymphadenopathy

  5. Source: Fan et al., Arch. Dermatol. 142 (2006) 1181-1184

  6. Case Report 1 (cont.) • Biopsy of lesion • Gram stain revealed numerous budding yeast cells • Pronounced inflammatory reaction including microabscesses of follicules and numerous lymphocytes and histiocytes • PAS staining documented round-to-ovoid cells/spores in necrotic areas as well as in dermis

  7. Source: Fan et al., Arch. Dermatol. 142 (2006) 1181-1184

  8. Case Report 1 (cont.) • Culture/Laboratory Work • Skin scrappings from both patient and dog grew yeast-like cells on Sabouraud Dextrose agar with or without olive oil supplement • Scanning electron micrographs revealed morphology consistent with Malassezia pachydermatis • Patient had no other underlying disease or immunosuppression

  9. Case Report 1 (cont.) • Treatment • Initially treated with antituberculosis agents because of slow culture results • After positive fungus culture results, patient was treated with itraconazole and potassium iodide • Lesion stopped growing but was still positive for fungus • Therapy changed to fluconazole with cryotherapy to remove lesion • Some hypopigmented scarring remained, but patient was free of infection after 15 months

  10. Source: Fan et al., Arch. Dermatol. 142 (2006) 1181-1184

  11. Case Report 2 • Rosales et al., Ped. Develop. Pathol. (2004) 7: 86-90. • Infant born after 23 weeks of gestation • Chronic lung disease • Necrotizing enterocolitis • Intraventricular hemorrahge • At 24 days post birth, developed hypotension • Treated empirically with amphotericin B • Hepatic lesion noted

  12. Case Report 2 (cont.) • Blood cultures were positive for Malassezia furfur on day 11 of treatment (day 35 of life) • Central line catheter was also shown to be positive for M. furfur • Removal of catheter resulted in negative fungus cultures for 2 weeks of amphoterin B therapy

  13. Case Report 2 (cont.) • Day 50 of life • Patient’s condition worsened due to intestinal perforation • Surgery improved condition and was being given intravenous hyperalimentation infusions of lipids via a scalp catheter

  14. Case Report 2 (cont.) • Day 83 of life • Patient’s condition worsened again and seizure occurred • Spinal fluid examination revealed fungal forms consistent with M. furfur • Catheter and blood cultures were positive for M. furfur • Death occurred on day 86

  15. Source: Rosalles et al., Ped.Devel. Pathol. 7 (2004) 86-90

  16. Case Report 2 (cont.) • Autopsy findings • Inflammatory reactions of meninges consistent with meningitis • Histopathological examination (silver stained sections) revealed meninges contained yeast cells with morphologies consistent with M. furfur • No such observations were noted for any other organs in the body

  17. Source: Rosalles et al., Ped.Devel. Pathol. 7 (2004) 86-90

  18. Pityriasis Versicolor • Synonym: tinea versicolor, among others • Presentation: • Chronic, benign skin disorder • Asymptomatic • Characterized by scaly patches of varible color (pink, white, or brown) of the upper trunk • Worldwide in distribution

  19. Pityriasis Versicolor (cont.) • Etiological Agents: • Various species of Malassezia: • M. furfur • M. globosa • M. sympodialis • M. sloofiae • M. restricta

  20. Pityriasis Versicolor (cont.) • There are other species of Malassezia which may or may not be involved in pityriasis versicolor • M. obtusa • M. pachydermatis - common pathogen of dogs • Malassezia is a basidiomycetous yeast, but the telomorph has yet to be described • Different species differentiated based upon: • Physiological parameters, including use of complex lipid sources • Genetic-based differences

  21. Pityriasis Versicolor (cont.) • Epidemiology: • Typically an infection of children and young adults • Associated with hormonal changes and increased sebum production • Favored by high temperature and humidity, particularly tropic areas

  22. Pityriasis Versicolor (cont.) • Clinical manifestations • Multiple macules and/or patches varying in appearance • Hypopigmented • Hyperpigmented • Erythematous • Commonly affected areas include back, chest, abdomen, neck, and upper limbs • Children often acquire facial macular lesions

  23. Pityriasis versicolor. Source: www.doctorfungus.com

  24. Lesions of pityriasis versicolor. Source: www.doctorfungus.com

  25. Pityriasis Versicolor (cont.) • Diagnosis • Typically, KOH preps of lesions that show yeast and pseudohyphal elements (“spaghetti and meat balls”) • Can confirm the diagnosis by using a Wood's lamp to show yellow to yellow-green fluorescence of active lesions.

  26. “Spaghetti and Meat Balls” - Malassezia furfur (PAS stain). Source: www.doctorfungus.com

  27. Pityriasis Versicolor (cont.) • Treatment is via use of topical agents including: • Selenium sulfide shampoo • Zinc pyrithione shampoo • Ciclopirox • Terbinafine • Benzoyl peroxide

  28. References • Clinical Mycology. 2003. Elias J. Anaissie, Michael R. McGinnis, Michael A. Pfaller, eds. Churchill Livingstone • Clinical Mycology. 2003. William E. Dismukes, Peter G. Pappas, Jack D. Sobel, eds. Oxford University Press • Topley & Wilson's Microbiology & Microbial Infections, 10th ed. 2005. Vol. 3. Medical Mycology. Hodder Arnold

  29. References (cont.) • www.doctorfungus.com (accessed on June 3, 2007) • Ashbee, H. R. 2007. Update on the genus Malassezia. Med. Mycol. 4: 287-303. • Morishita, N., Sei, Y. 2006. Microreview of pityriasis versicolor and Malassezia species. Mycopathologia 6: 373-376.

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