In dengue infection, number of petechial spot per square inch in cubital fossa should be:

1. Dengue hemorrhagic fever is diagnosed by positive Tourniquet test which indicates number petechial spot per square inch in cubital fossa is >20 per 2.5 cm (1cm) square area. 2. Tourniquet test: Done to detect thrombocytopenia. The standard method uses the blood pressure cuff. To identify dengue and chikungunya infection. Positive tourniquet test - Number of petechial spot per square inch in cubital fossa is 20. Any of the following may be present - petechiae, purpura, ecchymosis, epistaxis, gum bleeding hematemesis or melena. 3. Criteria for diagnosis of dengue hemorrhagic fever (DHF): Fever - acute, high and continuous for 2-7 days. Positive tourniquet test. Enlargement of liver.