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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

Infections Due to Malassezia

Presenter: Dr. Cooper

definition
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
case report 1
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
case report 1 cont
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
case report 1 cont1
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
case report 1 cont2
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
case report 1 cont3
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
case report 2
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
case report 2 cont
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
case report 2 cont1
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
case report 2 cont2
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
case report 2 cont3
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
pityriasis versicolor
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
pityriasis versicolor cont
Pityriasis Versicolor (cont.)
  • Etiological Agents:
    • Various species of Malassezia:
      • M. furfur
      • M. globosa
      • M. sympodialis
      • M. sloofiae
      • M. restricta
pityriasis versicolor cont1
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
pityriasis versicolor cont2
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
pityriasis versicolor cont3
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
pityriasis versicolor cont4
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.
slide26

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

pityriasis versicolor cont5
Pityriasis Versicolor (cont.)
  • Treatment is via use of topical agents including:
    • Selenium sulfide shampoo
    • Zinc pyrithione shampoo
    • Ciclopirox
    • Terbinafine
    • Benzoyl peroxide
references
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
references cont
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.