Insertion of intradermal needles into painful points provides analgesia for intractable abdominal scar pain

Abstract

Background and objectives: Conventional treatments are often ineffective for patients having painful abdominal scars. There are painful points in and around scar tissue. We tested the hypothesis that insertion of intradermal needles into these painful points reduces scar pain.

Methods: Patients with abdominal scar pain with painful points that is not relieved by conventional treatments were allocated to a treatment group (n = 23), a sham-treatment group (n = 23), or a control group (n = 24). In the treatment group, intradermal needles were inserted into painful points detected by a pressure threshold meter (pain < or = 2.5 kg/cm(2)). In the sham-treatment group, the same needles were inserted into nonpainful points. The needles were kept in place for 24 hours. This process was repeated 20 times over a 4-week period. Responses were evaluated before and at the end of treatment, and 4 and 26 weeks after the treatment. Continuous and lancinating pain was evaluated on a 10-cm visual analog scale. We measured the area of pain and the pressure required to initiate painful-point pain. All patients took diclofenac as needed and completed a diary of daily diclofenac consumption.

Results: Patients in the treatment group showed a marked reduction in all pain parameters (>70%). In contrast, analgesia was minimal in the other groups. The decreases in the pain threshold pressure correlated with the decreases in continuous and lancinating pain (r =.57 and r =.63, respectively).

Conclusion: Our data suggest that insertion of intradermal needles into painful points is a remarkably effective treatment for intractable abdominal scar pain. Analgesia presumably results from inactivation of painful points, through a yet to be elucidated mechanism.