Hair infection with scutula formation is seen is case of-

<Tinea capitis it is is superficial fungal infection of scalp and hair with dermatophytes . Commonest mycosis in children's Fungus grows over scalp and extend down in hair follicles till zone of keratinisation-adamsons fringe. According to the inflammatory component of clinical presentation tinea capitis classified as Inflammatory-keerion and us Non inflammatory- grey patch and black dot According to size and location of spores Ectothrix-spores outside hairshaft hairs appear dull and grey Endothrix-spores inside hair shaft- hairs break at the follicular orifices appear as black dots on scalp Clinical presentation :four different clinical presentations Grey patch or non inflammatory type:patches of hair loss with broken dull looking hairs.causative organism- microsporum audounii,M.canis,M.gypseum Kerion or inflammatory type : kerion is a inflammatory boggy swelling , indurated tender swelling that is studded with broken ,unbroken hairs , vesicles and pustules. There is sinus formation thick crusting.heals with scarring. Causative organism trichophyton verrucosum and trichophyton mentagrophytes Black dot or non inflammatory type: endothix infection.hairs break at the level of scalp appear as black dot on scalp. Favus: inflammatory type: yellow cup shaped crust composed of dense meat of mycelia and debris-scutula.concavity of cup faces up.endemic in Kashmir. Causative organism T.schoenleinii. Diagnosis: Woods lamp: Bright green fluorescence- M.canis,M.audounii,M.gypseum Dull green fluorescence- T.schoenleinii Direct demonstration KOH mount Treatment Drug of choice for tinea capitis-griseofulvin 15-25mg/kg/day for 2-4 months Other drugs- itraconazole ,fluconazole,terbinafine Topical therapy not effective Antifungal shampoos like ketoconazole and selenium sulphide decrease carrier state. iadvl textbook of dermatology page 254