Dengue is hyperendemic in Bangladesh, and thrombocytopenia is among its most common laboratory findings; although a low platelet count is frequently alarming to patients and clinicians, it usually resolves spontaneously during the convalescent phase. A range of unproven “platelet-boosting” measures including vitamin K, tranexamic acid and herbal preparations are widely used in the region despite the absence of a supporting mechanism or controlled evidence. We report a 55-year-old man who presented with fever, headache, nausea, arthralgia and hemoptysis. Dengue NS1 antigen was positive, and complete blood count showed severe thrombocytopenia (18,000/µL) with hemoconcentration (hematocrit 48.7%). He managed conservatively with paracetamol, oral fluids and monitoring; tranexamic acid and injectable vitamin K1 were also administered on clinical grounds. He recovered uneventfully, with the platelet count rising to 453,000/µL and the hematocrit normalizing to 39.6% approximately two weeks after symptom onset. The platelet recovery in this patient followed the well-recognized natural history of dengue and cannot be causally attributed to vitamin K or tranexamic acid. Vitamin K has no role in thrombopoiesis, and this case is best read as a reminder that spontaneous recovery in a single, uncontrolled case must not be mistaken for treatment effect. Adult dengue with mucosal bleeding nonetheless warrants close monitoring for warning signs.