**4. Hyperalgesia and location of trigger points on the abdomen**

Associated with the allodynia, one can determine the presence of hyperalgesia, which is an increased pain sensation from a painful source. The examining finger can detect this when gently applied to the area (**Figure 5**). The examination has to be gentle as a pressure of only 15–20 g can evoke severe pain from the small nodular trigger point (**Figure 5**). The location of the trigger point has been marked in **Figure 6**.

A more sophisticated way of determining the degree of hyperalgesia is with an algometer. This instrument will determine the pressure pain threshold. Measures of pressure pain thresholds are reduced in the areas affected by pain sensitization. In many cases of severe chronic pelvic pain, it is possible to put only the mildest

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*Pain Testing in Endometriosis for the Clinician DOI: http://dx.doi.org/10.5772/intechopen.92756*

threshold recorded.

**Figure 6.**

were as follows:

pressure in the region of the anterior cutaneous nerve to have the induced pain

*The location of the trigger point corresponds to the right anterior cutaneous nerve from T12 spinal nerve.*

In a cohort of 81 women with chronic pelvic pain, the presence of allodynia was significantly associated with those who were suffering from visceral disease [13]. The positive predictive values for pelvic visceral disease were as follows:

Abdominal cutaneous allodynia 93% Perineal cutaneous allodynia 91% Abdominal myofascial trigger points 93% Perineal myofascial trigger points 81% Reduced pain thresholds 79%

Abdominal cutaneous allodynia 4.19 (1.46, 12.0) Perineal cutaneous allodynia 2.91 (1.19, 7.11) Abdominal myofascial trigger points 4.19 (1.46, 12.0) Pelvic myofascial trigger points 1.35 (0.86, 2.13) Reduced pain thresholds 1.14 (0.85, 1.52), [13]

In order to have faith in allodynia, it is important to ensure the test has reliability.

The likelihood ratio (+) and 95% C.I. for the detection of visceral sources of pain

In another study of validity, a total of 22 females with chronic pelvic pain were compared to 23 pain-free controls and 12 cyclic pain patients. Participants were evaluated by two clinicians. Investigators mapped the abdomen with the cottontipped applicator, outlined the areas of allodynia with a body pen, photographed the abdomen, and wiped off the marking before the second investigator repeated the test. The interrater reliability resulted in 98% agreement for the three study

**5. Validity of allodynia testing in pelvic pain**

*Pain Testing in Endometriosis for the Clinician DOI: http://dx.doi.org/10.5772/intechopen.92756*

*Endometriosis*

**4. Hyperalgesia and location of trigger points on the abdomen**

Associated with the allodynia, one can determine the presence of hyperalgesia, which is an increased pain sensation from a painful source. The examining finger can detect this when gently applied to the area (**Figure 5**). The examination has to be gentle as a pressure of only 15–20 g can evoke severe pain from the small nodular trigger point (**Figure 5**). The location of the trigger point has been marked

*An example of allodynia expansion upward by dermatome with each test for allodynia in a woman with severe* 

A more sophisticated way of determining the degree of hyperalgesia is with an algometer. This instrument will determine the pressure pain threshold. Measures of pressure pain thresholds are reduced in the areas affected by pain sensitization. In many cases of severe chronic pelvic pain, it is possible to put only the mildest

*Localizing a viscerally related trigger point with gentle pressure from the pulp of the examining finger.*

**64**

**Figure 5.**

in **Figure 6**.

**Figure 4.**

*pelvic pain.*

**Figure 6.** *The location of the trigger point corresponds to the right anterior cutaneous nerve from T12 spinal nerve.*

pressure in the region of the anterior cutaneous nerve to have the induced pain threshold recorded.
