Page 164 - AIDSBK23C

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CMV inclusions may be more frequent. The cytomegalic cells may be accompanied by small
foci of chronic inflammation, necrosis, or hemorrhage. Viral culture may be performed, but is
generally not useful because, in the absence of histologic evidence for infection, detection of
CMV is of uncertain significance.[138] Use of immunohistochemical staining can help in
identification of CMV in difficult cases.[690]

TOXOPLASMOSIS.-- Toxoplasmosis may rarely produce mucosal erosions in the colon,
but is typically not associated with gross lesions. Microscopically, it is characterized by mixed
inflammatory cell infiltrates of mucosa and submucosa in a haphazard pattern, and with little
cellular necrosis. Unless Toxoplasma gondii cysts or tachyzoites are found, the diagnosis cannot
be made with certainty.[475]

HERPES SIMPLEX VIRUSES.-- Herpetic lesions of the GI tract typically involve the
perianal region and the esophagus. Involvement of the lower GI tract may be produced by
extension of lesions from perianal skin to the anorectal junction and to rectum with clinical
findings of anorectal pain, tenesmus, constipation, and inguinal lymphadenopathy. Diarrhea may
occasionally complicate proctitis.
Herpetic esophagitis is second in frequency to candidiasis as a cause for odynophagia,
and dysphagia may also occur. The oral cavity and esophagus may also be involved with small
discrete "punched-out" ulcerations. Anorectal ulcerations can be caused by herpetic
infection.[689] Grossly, crops of clear vesicles can evolve to chronic ulceration and induration.
A common radiologic manifestation is the appearance of multiple small discrete ulcers in a
normal background mucosa.[416] Microscopic diagnosis is made by finding ground glass,
mauve to pink, intranuclear inclusions in cells that are clustered or multinucleate. Surrounding
squamous epithelium may show ballooning degeneration. Acyclovir, or foscarnet if resistance
develops, may be helpful for therapy.[396,487,490]

SPIROCHETOSIS.-- Intestinal spirochetosis with the organism Brachyspira aalborgi
can lead to chronic diarrhea in HIV-infected persons, most often in men having sex with men
and who have not reached the stage of AIDS. Colonoscopy often reveals a normal appearing
mucosa. Biopsies examined microscopically with Warthin-Starry staining are more likely to
detect the spirochetes. Treatment with metronidazole or penicillin is effective.[691]

ORAL CAVITY CHANGES.-- A fourth to half of all persons infected with HIV will
have one or more oral lesions during the course of their infection, and in 10% an oral lesion will
be the first manifestation of their illness. The most common lesions are: oral candidiasis, hairy
leukoplakia, periodontitis, gingivitis, aphthous ulcers, and Kaposi's sarcoma. Oral candidiasis is
discussed above. Symptoms may include xerostomia and burning mouth syndrome. Oral papules
and ulcers may appear on buccal mucosa with Histoplasma capsulatum and Penicillium
marneffei infections.[667,692]
Necrotizing gingivitis is seen in HIV positive patients and is characterized by marginal
gingival necrosis, bleeding and pain. When this process extends into the periodontal attachment
apparatus, it is know as necrotizing periodontitis. These two conditions are collectively known
as necrotizing periodontal diseases, and they are similar with regard to the spectrum of
periodontopathic bacteria, the clinical manifestations, the natural course and the response to
treatment compared to persons not infected with HIV. Cases of acute necrotizing gingivitis