[Comparison of two lancets in the skin prick test]. / Comparación de dos lancetas en la prueba cutanea por punción.

ABSTRACT

BACKGROUND: The skin prick test is used to diagnose the allergic sensitization. Its results depend upon several factors, such as the lancet type. In Cuba, the most frequently used are ALK lancet and blood lancet. OBJECTIVE: To compare these two lancets regarding the size of the wheal, precision, sensitivity and specificity of the skin prick test and, finally, the preference of the patients to one of them. PATIENTS AND METHODS: The study was performed in 60 allergic patients, aged 15-50 years, seen at the allergy service of Hospital Universitario Clínico Quirúrgico General Calixto García. The skin prick test was performed on the forearm of all patients included, using both lancet types. A negative control (diluent solution) was applied, together with a 54.3 mmol/L histamine solution in five replicates. RESULTS: The mean size of skin reaction to histamine was 6 mm, using a 1 mm single peak lancet (ALK), size was 6.5 mm when using blood lancet (significant difference p < 0.05). Precision, sensitivity and specificity of ALK lancet were 9.7, 100 and 100%, respectively. On the other hand, the respective values for blood lancet were 15.9, 96 and 87%. Of those studied, 27% presented mild pain and 3% moderate pain using the ALK lancet; while 25% showed mild pain and 10% moderate pain using the blood lancet. CONCLUSION: The ALK lancet showed more precision, sensitivity and specificity and it was preferred by the patients.