Hypersensitivity

Hypersensitivity 

     

Air born spores Fungal elements Act as antigenic stimulants Immunological state of individual Induce hypersensitivity Production of immunoglobulin Sensitized lymphocytes

Hypersensitivity Cont.    

As Hypersensitivity pneumonitis Include rhinitis Bronchial asthma Various form of atopy

Colonization and resultant diseases Fungi are free living organisms  Human have high level of immunity  Most infection are mild  Or self limiting  Host immunity to fungal diseases  Skin, mucosal surface  Fatty acids, PH, normal flora  Humoral factors such as transferrin 

Classification of fungal diseases Superficial mycoses  Outermost layers of skin, hair  Cutaneous mycoses  Epidermis, invasive hair, skin, nail  Subcutaneous mycoses  Dermis, muscle and fascia  Systemic mycoses  Lung and spread other organs 

Fungal diseases Cont.  Opportunistic       

mycoses

Agents with low pathogenic Disease under certain conditions Host debilitations Change in the normal flora Cytotoxic drugs, steroids Immunosuppressive drugs and so on Candida species, Aspergillus, Cryptococcus

Superficial Mycoses Cosmetic problems  Easily diagnosed and treated  2 involves skin (stratum corneum)  Pityriasis versicolor  Tinea nigra  2 involves hair (cuticle)  Black piedra  White piedra 

Pityriasis versicolor Malassezia furfur (P. orbiculare)  A lipophilic yeast  Related to P. ovale  Area rich in sebaceous gland  Normal flora of skin  Infected area  Upper torso, arm, abdomen 

Clinical syndroms Hyper or hypopigmented lesions  May cause hair and skin folliculitis  Dandruff  Fungmia in patients receiving IV lipid therapy 

Pityriasis folliculitis

Laboratory diagnosis    

 

Direct microscopic examination Skin scraping KOH, alkali stain Fungal elements

Classical spaghetti appearance Short hyphae and yeast cell

Culture media Not necessary but may be  Required for fungmia  Epidemiological study  Treatment failure  Growth require lipid such as olive oil  Sabouraud dextrose agar 

Tinea nigra  Etiological

agent  Exophiala werneckii  Dimorphic fungi  Produce melanin pigments  Clinical syndroms  Grey to black demarcated lesion  Palm of hand and soles of feet

Laboratory diagnosis  Direct

microscopic examination  KOH, Alkali stain  Skin scraping  Darkly pigmented yeast-like cell  Hyphal fragmented  Culture  SDA  Black to brown yeast and hyphae

Black piedra     

Causative agent and disease Piedraia hortae Hard brown to black nodules Along hair shaft Ascospores on direct microscopic

White piedra Trichosporon beigelii  Hair of scalp  Moustache and beard  Clinical future  Soft white to creamy yellow granules  Form sleeve-like collarette  Along hair shaft 

Laboratory diagnosis   

Direct microscopic examination Culture on SDA without actidione Mycelium fragmented into arthroconidia

Treatment of superficial mycoses  Skin infection  Topical keratolytic agents  Azoles compounds  Oral antifungal for generalized Tinea.  versicolor 

Treatment Cont. Hair

infection

 Shaving  Proper

personal hygiene