Increase of confirmed Tinea nigra cases in the last years in Argentina

MALDONADO I; GIUSIANO G; SOSA MA; AMIGOT S; FLORES V; SANTISO G; ARECHAVALA A; FERNÁNDEZ N

Salvador de Bahía

Congreso; 17th Infocus and 1st ISHAM Latin American Congress; 2019

ObjectivesTo evaluate the epidemiological and microbiological features of eight confirmed cases of Tinea nigra in Argentina in the last years.MethodsThis is a retrospective study, from 2017 to July 2019, of confirmed clinical cases of Tinea nigra. The diagnosis was performed by clinical suspicion and mycological studies of cutaneous lesions. Laboratory diagnosis included direct examination of skin scrapings with KOH (10-40 %) and cultures at 28 °C for up to 30 days in Sabouraud glucose agar, with and without antibiotics. Isolates were identified based on their macro and micro-morphological features. Epidemiological data of each case were recorded.ResultsOut of the eight patients, seven children and one adult, two had been to areas where there is more incidence of tinea nigra, while the rest were from regions of Argentina where climate conditions for the pathology are optimal. Six cases corresponded to tinea nigra palmaris and two to tinea nigra plantaris. In all cases, the lesions were hyperpigmented, and direct examinations were positive, showing thick dematiaceous septate hyphae. A positive culture was obtained in seven of the patients and the isolates were identified as Hortaea werneckii. Treatment with local antifungals was performed in all but one of the patients. One case healed spontaneously without treatment.ConclusionThis shows an increase in confirmed cases during the last three years, some of them with no history of recent travel. Clinical presentation of this mycosis is similar to several dermatological conditions including malignant conditions such as melanoma, but the differential diagnosis can be performed with a simple non-invasive mycological test. We think that, due to the low incidence of this pathology, it is not a frequently suspected disease