Superficial mycoses

Mycology

1. INSTITUTE OF HEALTH TECHNOLOGY, DHAKA Department of Laboratory Medicine BSc in Health Technology (Laboratory)- 1 st Year MYCOLOGY Lecture No. 03 (Superficial Mycoses) By Sk. MIZANUR RAHMAN Lecturer, Mycology MS in Biotechnology & Genetic Engineering (UODA) MS in Microbiology (SUB)

2. Superficial mycoses pityriasis versicolor – causative fungus, lesion produce.

3. Anatomy of Skin Hair follicle and sebaceous gland

4. Fungal Infections/ Mycoses Superficial mycoses: 2 types: surface and cutaneous mycoses Skin, hair & nails. Mild but chronic disease Deep mycoses: 2 types: subcutaneous & systemic mycoses Caused by soil saprophytes Infection is accidental Range from a symptomatic infection to fatal disease

5. Superficial: Surface mycoses Live exclusively on dead surfaces of skin and its appendages No contact with living tissue, hence no inflammatory response Tinea versicolor Tinea nigra Piedra

6. Superficial: Surface mycoses

7. Pityriasis ( Tinea ) Versicolor Fungal infection of the skin This is a very common superficial mycoses caused by a lipophilic yeast Malassezia spp. It is seen in all countries but is particularly common in the tropics with more than 60 % of the population infected. The lesions are hypo or hyper pigmented. The etiologic agent is normal flora of man so the disease re-occurs. Multiple patchy lesions (oval shape c fine scales) either light in color or brown Typically occurs on the back, neck, chest, shoulders

8. Tinea Versicolor Recent evidence suggest that seborrheic dermatitis is also caused, or triggered by, Malassezia yeast. There also is Malassezia folliculitis . This is seen in patients who are usually severely ill or in patients after sun exposure. Tx : Topical antifungal

9. General Morphology Tinea Versicolor Numerous, well- marginated , oval-to-round macules ( change in the color of the skin) with a fine white scale when scraped. Pigmentary alteration uniform in each individual. Red Hypo pigmented Hyperpigmented Scattered over the trunk and neck. Seldom the face. M . furfur Normal flora of skin Asymptomatic.

10. Tinea Versicolor Definition Asymptomatic colonization Malassezia furfur Hypopigmentation Hyperpigmentation Seborrhoeic dermatitis Dandruff Fungaemia

11. Pityriasis versicolor Conditions: Health Sweat Greasy skin Chronic bacterial infections Steroids

12. Pityriasis versicolor Clinical manifestations: Maculae White, cream, pink, red, brown Scale/signs Painless Not itching

13. Superficial mycosis ( Pityriasis versicolor )

14. Superficial mycosis ( Pityriasis versicolor )

15. Pityriasis versicolor Laboratory diagnosis: Sampling Scalpel (sharp bladed instrument) Wood ́s lamp (producing ultraviolet radiation) Direct Culture

16. Tinea Versicolor Diagnosis: Scrape lightly – fine white scale KOH Positive for short hyphae and spores (Spaghetti – hyphae and meatballs- yeasts ) Woods Light – pale yellow white fluoresce. Culture rarely done.

17. Tinea Versicolor Direct exam. Skin scraping 10 % KOH preparation Parker Ink Culture Sabouraud Dextrose Agar Lipophilic yeast Flood with Olive oil

18. Tinea Versicolor

19. Tinea Vesicolor – Woods Light Yellow White

20. Short fragments of hypha cluster of yeast

21. M.ovalae M.paraovalae M.furfur Malassezia

22. Tinea Versicolor Microscope

23. Culture Malassezia furfur can be grown in a laboratory but only when one covers the culture with oil. This leads me to speculate that there is a genetic susceptibility to this disease resulting from qualitative or quantitative differences in the oil content of susceptible persons.

24. THANK YOU