Demonstration of Cutaneous Allodynia in Association with Chronic Pelvic Pain

Introduction

In most cases the areas of cutaneous allodynia will be identified in the dermatomes of the abdomen and perineum that innervate the intra-pelvic structures – T11-L1 and S3,4,5 respectively. The term allodynia refers to the presence of a painful sensation as a consequence of a stimulus that is not normally painful, in this case a cotton-tipped culture stick.

1. Abdomen

1. An explanation of the test is undertaken and permission to procede is obtained.
2. The woman exposes the abdomen from the rib cage to the region of the pubic bone.
3. A cotton-tipped culture stick is shown to the woman and brushed against her hand to demonstrate how the light pressure will feel.
4. The woman is asked to note the point at which light pressure applied to the skin becomes sharp as the cotton-tipped culture stick is drawn down the abdominal wall.
5. The cotton-tipped culture stick is then lightly drawn down the abdomen and the woman will either note the presence of no change in sensation or will note a sudden and discrete sharpness in sensation. The process is repeated until the entire area of cutaneous allodynia has been identified. A positive test is defined by the presence of this sudden sharp sensation.
6. In some cases the areas are large but in others they will be small. They can be unilateral but usually will be bilateral.

2. Perineum

1. An explanation of the test is undertaken and permission to procede is obtained.
2. The woman exposes the perineum in the lithotomy position.
3. A cotton-tipped culture stick is shown to the woman and brushed against her hand to demonstrate how the light pressure will feel.
4. The woman is asked to note the point at which light pressure applied to the skin becomes sharp as the cotton- tipped culture stick is drawn across the perineum.
5. The cotton-tipped culture stick is then drawn across the buttocks horizontally in a direction from the lateral aspect of the buttock to toward the anus to cut across the S3 dermatome. The process is repeated on the contralateral side. Additionally the cotton-tipped applicator can be drawn from the region of the labia majora in a directly posterior direction, avoiding the vaginal area. A positive test is defined by the presence of a sudden sharp sensation.
6. On the perineum, the area usually describes the S# dermatome when positive. Positive results can be seen unilaterally as well but less commonly.

The presence of cutaneous allodynia indicates the woman has had severe pain in the past to the extent that neuropathic changes have occurred. Although the problem may have originated from dysmenorrhea or endometriosis, a new condition has emerged – Chronic Pelvic Pain. The original condition may be active or quiescent. Recognition of this new development is important for patient education and to initiate processes of rehabilitative care. Recognition of the development of this state may also permit the clinician to explore other options and avoid potentially unnecessary surgery – particularly if the original condition has been treated.