THE EFFECT OF NON-DISPOSABLE STERILIZED BLUNT NEEDLES ON THE SENSITIVITY OF PATHERGY TEST IN BEHCET’S DISEASE

^{M. Hakim, MD* Sh. Samangooei, MD* M.A. Nazari Nia, MD**}

* Department of Medicine. Rheumotology Division, Shiraz University of Medical Sciences

** Department of Medicine. Rheumotology Division, Shahid Beheshti University of Medical Sciences

This prospective study was conducted to find out The accuracy of Pathergy test, which is the hyperactivity of skin to needle trauma, in patients with behcets disease, and to compare the results with current universal method, using disposable sharp needles in patients with (BD) in South West of Iran.

The study was done during April 1996 – August 1998 in Behcets Disease Research clinic in Shiraz univercity of Medical Sciences.

The pathergy phenomenon was tested simultaneousluy on the skin of forearm on 104 (71 female and 33 male) BD patients with active disease and on 100 healthy persons as control group. two methods for pathergy test were used: 1- the old method, using the blunted needles that were non-disposable, sterilized 21 gauge (G) needles and 2- the new current standard method with sharp-disposable needles, in three different gauges including: 21G, 23G plus intradermal injection of 0.1cc normal saline (N/S) and skin scratches by 25G needles. The skin reactions were checked 24-48 hours later by the same physician for possible developing erythema of more than 2mm in diameter, papules or pustules at the sites of needle insertion (called positive pathergy test). At the end of 17 months, the data were analyzed to compare the sensitivity and specificity of the both tested pathergy phenomenon by blunt and sharp needles.

Correspondence to:

M. Hakim

Department of Medicine. Rheumotology Division, Shiraz University of Medical Sciences

By using the blunt needles, positive pathergy test was seen in 85 out of 104 BD patients and in 3 out of 100 of healthy control group, (sensitivity of 80.7% and specificity of 97%).The pathergy test with more traumatic method, that is using intradermal injection of 0.1 cc N/S with 23G sharp needle insertion, resulted 69 out of 104 patients with positive test and 3 out of 100 in healthy control persons (sensitivity of 66% and specificity of 97%).

In this study we observed that using non-disposable, sterile blunt needle in performing the pathergy test in BD patients (old method) increases the sensitivity of pathergy test to 80.7% in comparison to current standard method in which disposable-sharp needle is being used.

Keywords: Behcet’s Syndrome – Needles – Skin Tests