SUPERFICIAL FUNGAL INFECTION

þ Dermatophytosis/ Tinea infection / Ringworm infection

þ Pityriasis versicolor / Tinea versicolor (Malassezia furfur)

þCandiasis

A dermatophyte is a fungus  that has developed the ability to live on the keratin (hairs, nail or skin)

TYPES OF TINEASIS (Based on site of involvement)

Scalp –Tinea capitis (a) Inflammatory type : Kerion,   Favus

(b) Non- inflammatory type: Grey patch,   Black dots

2. Beard –Tinea barbae    3. Face —Tinea faciei  

4. Trunk, extremities —Tinea corporis / Tinea circinata

5. Groin/ Upper and inner surface of thigh —Tinea cruris

6. Hand —Tinea manuum

7. Foot —Tinea pedis

8. Nails bed —Tinea  unguium/ Onychomycosis

Remember Notes

Contagious disease

Mode of Transmission

    ¥Direct contact ¥Susceptible person : DM, Immunosuppressed persons 

Hot and humid (moisture) environment

Excessive use of water / water exposure

HIV Infection,

Poor hygiene and poor nutritional status

Classical Presentation of Tineasis:

Single or multiple rounded or ring like Pruritic patches presentating as central clearing with peripheral elevated border.

Q. D/D of Annular patches/ Ring worm:

1.Nummular eczema

2.Granuloma annulare

3.Annular psoriasis

3.Secondary syphilis

4. 2.Annular sarcoidosis

Progressive central clearing produces annular outlines that give them the name – “Ring worm”

 Dermatophytes: Epidermatophyton (Nail and skin),                                             Trichophyton (Hair, skin , nail ) ,Micrsporum (Hair, skin, nails )       

 Tinea Þ Ring worm / Dermatophytes

Taenia Ü Tapeworm          

 Hypha– individual fungal element           

 Most of the fungal infections of skin  are caused byTrichophyton rubrum

Most of the fungal infections of  hairs are caused by Trichophyton tonsurans, Microsporum canis

Proximal and distal subungual onchomycosis commonly caused by Trichophyton rubrum

Superficial white onchomycosis is caused by Trichophyton mentagrophytes

Permanent hair loss may occur in inflammatory type of Tinea capitis

Majority of fungal infection occurs as self healing process

Dermatophytes do not invade below to skin because of serum feratin and other chelators and fungi cannot tolerate  above  35 0 C

Ergesterol is the main sterol of the fungal membrane 

Acetyl-CO-A  → Squalane → Lanosterol → Ergesterol

                                                Allylamin       Azoles                (cell membrane)                                                  

10% to 20% KOH  for  keratolysis and visualization of fungus elements

 40 to 60%KOH taken for dissolution of all materials

Alternative of KOH is Xylol (no heat required)

DIFFERENCE BETWEEN : Eczema & Tineasis

LABORATORY DIAGNOSIS OF SUPERFICIAL FUNGAL INFECTION/TINEA

Skin scrapping  for fungi/ Nail shaving/Hair plucking with roots ¥ KOH (10-20%) preparation for M/E(Heating)  reveals  definite hyphal elements tranasversing several epidermal cells

Culture ( 5 to 14 days)  üSeboraud’s Dextrose Agar (peptone water + dextrose + agar agar)

üMycosel or mycobiotic agar media (Seboraud’s Dextrose Agar + Cycloheximide+ Chloramphenicol)

üDermatophyte test media (DTM)

Selective and Indicator media (Seboraud’s Dextrose Agar + Cycloheximide + Gentamycin + Phenol) ¤If  dermatophytes present, red ¤Saprophytes present ,green, Candida  present,  no color change , but characteristic typical yeast colony

3. Wood’s  Lamp Examination: Bright blue green fluorescence (Pterydine)

4. PCR (Polymerase Chain Reaction)

5. SKIN BIOPSY for histological examination

ANTIFUNGAL DRUGS:

Systemic                                                                                Topical

1.Griseofulvin (500 mg tab) Best For Tinea capitis                    1.  Miconazole cream

2. Fluconazole (Best for all cases) 50 mg/ 150 mg cap            2. Econazole cream

3. Itraconazole (100 mg cap)                                              3.   Clotrimazole cream

4. Ketoconazole (200 mg tab)                                            4. Ticonazole cream

5. Terbinafine (250 mg tab)                                                5. Ketoconazole 2%                                                                                                              shampoo

                                                                                           6. Terbinafine cream

                                                                                          7.Whitfield ointment

                                                                                          8. Selenium sulfide Lotion

NOTE:

 Most of the antifungals (systemic) are hepatotoxic in high dose or long term use

* Systemic antifungal are not safe in pregnancy

*Most of the antifungal are hepatotoxic in high dose  or long term use

*Relatively safe (a) in renal impairment  – Intraconazole

 (b) in hepatic impairment  – Terbinafine

Whitfield ointment (Benzoic acid (antifungal) +(salicylic acid (keratolysis)…Cheapest

Selenium sulfide  : 2.5% lotion /shampoo (Seloun shampoo)

Best for Pityriasis versicolor