Situation: Dengue cases are being reported in a densely populated barangay during the rainy season. The nurse at the Barangay Health Station (BHS) sees febrile children and works with the barangay officials. For a 9-year-old boy with 2 days of fever, the nurse inflates the blood pressure cuff midway between the systolic and diastolic pressures for 5 minutes. She then counts 6 petechiae in a 2.5 cm × 2.5 cm square on the forearm. How should she interpret this result?

The tourniquet test is read as positive at 20 or more petechiae in a 2.5 cm × 2.5 cm square (some references use 10 or more per square inch), so a count of 6 is negative by either cut-off. The test supports a dengue diagnosis but is not specific or sensitive enough to confirm or exclude it, so the child is still monitored for fever and warning signs.

Interpreting the Tourniquet Test Result

The nurse counted 6 petechiae in a 2.5 cm × 2.5 cm square. The standard cut-off for a positive tourniquet test is 20 or more petechiae in that same area, although some references accept 10 or more per square inch as an alternative threshold. A count of 6 falls below both cut-offs, so the result is negative.

However, a negative tourniquet test does not rule out dengue. The test reflects capillary fragility and thrombocytopenia, which are not present in every dengue case, especially early in the illness. The boy has only had fever for 2 days, and capillary leakage may not yet be pronounced. The tourniquet test supports a dengue diagnosis when positive, but its low sensitivity means a negative result cannot exclude dengue.

Watch out! A positive tourniquet test is not confirmatory for dengue either. Other conditions causing capillary fragility or thrombocytopenia—such as scrub typhus, Epstein-Barr virus infection, or other viral illnesses—can also produce petechiae. The test is a bedside screening aid, not a definitive diagnostic tool.

The large Brazilian analysis of 28,000 tourniquet test trials found that the test has low sensitivity for differentiating dengue from other febrile illnesses ^[1]. This means many true dengue cases will have a negative tourniquet test. Similarly, a study among Lao adults with suspected dengue found that the admission tourniquet test alone was insufficient to confirm or exclude dengue; serological testing was required ^[2]. The Rumpel-Leede phenomenon—petechiae appearing distal to a cuff—can occur with any condition that increases capillary fragility, not just dengue ^[3].

Because the tourniquet test is neither sensitive nor specific enough to confirm or exclude dengue, a negative result in a febrile child from an endemic area still requires close follow-up. The nurse should monitor the boy for continued fever, warning signs (abdominal pain, persistent vomiting, mucosal bleeding, lethargy), and arrange appropriate dengue testing if clinically indicated.

Key point! The tourniquet test result of 6 petechiae is negative by standard cut-offs, but dengue remains possible. The child should be followed for fever progression and warning signs rather than being discharged from care.