Validity of tourniquet test in dengue haemorrhagic fever

Dengue haemorrhagic fever (DHF), a public problem in most of the tropical countries of South-East Asia, is diagnosed on the basis of demonstrating an increased capillary permeability and thrombocytopenia with concurrent haemoconcentration. Tourniquet test has been recommended as the initial screening procedure of patients with suspected DHF, particularly grade I DHF. The objective of the present study was to study the value of this test as an indicator of haemorrhagic tendencies in patients of DHF.

One hundred and ten adult patients hospitalized with DHF during outbreak of DHF in 1996 in north India were prospectively studied. The diagnosis of DHF was considered on the basis of haemoconcentration > 20%, evidence of transudation, or presence of shock along with thrombocytopenia. A tourniquet test was conducted in these cases in the standard method.

Of the 110 patients of DHF studied, 62 patients (56.4%) had bleeding but tourniquet test was positive in only half of these patients. Forty eight patients (43.6%) did not have any bleeding and the tourniquet test was positive in only 27% cases.

The tourniquet test was positive in only 39.1% of all DHF cases. It is concluded that a negative tourniquet test may not be sufficient to exclude a diagnosis of DHF in a febrile patient. This necessitates the need for the re-defining the clinical criteria for the diagnosis of DHF, particularly grade I DHF.