The Clinical Aspects,Pathogen Identification And Dermoscopic Characteristics Of Tinea Incognito

Objective: To reduce the incidence rate and the misdiagnosis rate of tinea incognito,investigating clinical aspects and the distribution of the pathogenic dermatophyte species and observing dermoscopic characteristics.Methods: 1.We collected clinical data of tinea incognito in Affiliated Hospital of North Sichuan Medical College from Jan.2016 to Jan.2017.Making full use of morphology and molecular biology technology in our study to identify pothogenic dermatophyte species.2.To explore the dermoscopic characteristics and these patterns changes after treatment,we had collected skin lesion pictures of tinea incognito during the whole process of treatment and compared with typical tinea corporis,eczenma,psoriasis,facial dermatitis and pipyriasis rosea.Results: 1.There were 49 cases involved in our study,and 25 cases were males,24 females.The average age was 29.11± 21.89 years old.In our study 34 cases(69.39%)residents lived in rural.The shortest course of disease is 4 days,however,in some cases,clinical course even lasted for more than 10 years.The lesions occurred in face,imbs,truncus,perineum hips and neck.Tinea incognito had been misdiagnosed as eczema,neurodermatitis,facial dermatitis,folliculitis,psoriasis,insect bite dermatitis,rosacea and herpes zoster.And 41 patients used non-antifungal drugs.Four dermatophyte species were identified.The most species were Trichophyton mentagrophytes(65%),followed by Trichophyton rubrum(25%),Microsporum cains(6%),Trichophyton tonsurans(4%).2.Dermoscopic characteristics before treatment included atypical vascular,polygon vascular network,hair follicles surrounding yellow halo,hair follicles embossment,markedly decreased vellus hair,polygon vascular network were significant statistic difference between typical tinea and tinnea incognito(P < 0.05).Atypical vascular,polygon vascular network,hair follicles surrounding yellow halo,hair follicles embossment and markedly decreased vellus hair were statistic difference between tinea incognito and non-dermatophytes diseases(P<0.05).Conclusions: 1.Tinea incognito were not only related to corticosteroid,but also associated with pathogenic dermatophyte species,habits,living environment and the host's own health status.2.The most pathogenic dermatophyte species were Trichophyton mentagrophytes and tinea incognito mostly occurred on face and misdiagnosed as eczema.3.Dermoscopic characteristics included atypical vascular,polygon vascular network,hair follicles surrounding yellow halo,hair follicles embossment and markedly decreased vellus hair.4.Dermoscopy could play an important role in diagnosing and evaluating curative effect of tinea incognito.