Acute constipation due to abdominal herpes zoster: an unusual association.

The association of herpes zoster and acute constipation, or even colonic pseudo-obstruction, has received only scant attention in the published literature. Since 1950, twenty studies have been published with 28 patients reviewed. Significant co-morbidities were present in half of the patients while the time of skin eruption was variable when compared with the onset of the abdominal symptoms. The majority of patients was observed and treated conservatively [1].

Herein we present a male patient with acute severe constipation and a concomitant painful skin eruption due to herpes zoster.

An 80-year-old diabetic man was admitted to our Department for abdominal distention, discomfort and severe constipation for a week. He previously had regular bowel habits. One day before presentation he noticed erythema with the appearance of small grouped vesicles involving the area of the T10-T12 dermatomes on the right abdominal wall (Fig.1). Physical examination revealed scarce bowel sounds and abdominal distention. Laboratory testing was normal with the exception of a mild hyperglycemia (207 mg/dL). Neurological examination revealed no evidence of myelopathy that might cause severe bowel dysfunction. He had no bladder dysfunction. Abdominal roentgenogram did not show a pattern of ileus and a colonoscopy was unremarkable. The patient was diagnosed as having visceral neuropathy associated with herpes zoster infection. He was treated with Vancyclovir 1000 mg t.i.d. with gradual resolution of symptoms during the next two weeks.

Figure 1

A cutaneous vesicular eruption involving the area of the T8-T12 dermatomes on the right

The pathogenesis of herpes zoster-associated intestinal pseudo-obstruction has not yet been fully elucidated. Direct viral involvement of the colonic intrinsic autonomic nervous system has been thought to result in local inflammatory reaction, thus causing segmental spasm and proximal dilatation [2]. Another theory has been proposed to explain pseudo-obstruction with prominent colonic dilatation. The theory includes spread of the virus from the dorsal root ganglia to the thoracolumbal or sacral lateral columns resulting in autonomic balance, interruption of sacral parasympathetic nerves, and resultant decrease in segmental colonic contractions [3]. Finally, direct involvement of the intrinsic colonic autonomic nerves (submucosal and myenteric plexuses) has also been discussed [4].

Herpetic neuralgia in a dermatomal distribution preceding the rash has long been recognized and noted to antedate the rash by up to 100 days, thereby creating significant diagnostic confusion [5]. The viral spread can involve not just the colon, but also the diaphragm, urinary tract, anus, and abdominal wall, and affect their motor activity [6].

The prognosis is generally good. The need for antiviral therapy should be based on immune status of the patient, the dermatome involved and the likelihood of visceral dissemination. Conservative management can achieve complete resolution of symptoms [7].