Hemorrhagic Manifestations in Primary DENV-3 Infection: A Case of Dengue with Warning Signs in an Adolescent.

Severe dengue is typically linked to secondary infection. We report dengue with warning signs due to primary DENV-3 infection in a healthy Italian adolescent returning from the Philippines. Severe thrombocytopenia and mucosal bleeding, with clinical and laboratory features suggestive of possible plasma leakage, were managed without shock, highlighting the need for multidisciplinary monitoring and care even in primary dengue.