abscess around the anus presents with swelling and redness
*One should rule out Crohn’s and tuberculosis while dealing with anorectal abscesses.
*cryptoglandular origin, conditions like Crohn’s, HIV, actinomycosis, and tuberculosis may also be associated with abscesses
*According to cryptoglandular theory, obstruction in the ducts causes stasis in the anal glands, leading to infection, abscess, or fistula formation
*Other causes include [8]:
• Tuberculosis • Actinomycosis • Crohn’s disease • Malignancy • Anal fissure infecting the anal gland • Pelvic infections resulting from appendicitis, diverticulitis, and gynecologic sepsis [8] • Radiation • As a postoperative complication of episiotomy, hemorrhoidectomy, and closed internal sphincterotomy • Immunocompromised patients • Penetrating injuries like gunshots, stab wounds, sexual trauma caused by anal sex, and accidental injuries • Trauma due to surgeries or ingested chicken or fish bones. Sometimes ingestion of tooth pricks may also puncture the rectal wall and cause an abscess [8]
*Pathogenesis of Abscess Once the anal glands become infected, they fail to drain through the anal ducts at the dentate line. Inadequate draining of these glands causes abscess formation, which extends along a path of minimal resistance, usually into the intersphincteric, ischiorectal, or supralevator regions [7, 9]. Crohn’s and Tubercular infection may also occur because of lymphoid follicles surrounding the anal glands [9].
Some authors believe that fistula-in-ano or abscess results from a congenital abnormality [10]. Predisposing factors like excess androgens may lead to infection, thus supporting the congenital theory. However, the cryptoglandular theory is most widely accepted
**formation of an intersphincteric abscess is an essential intermediate phase.It most commonly spreads caudally into the submucosa due to the direction of anal glands ramifications.
*perianal abscess forms when the abscess extends downward from the anal sphincter toward the anal margin.
*Ischiorectal abscess may result from the spread of the infection through the external anal sphincter.
*high intermuscular abscess results when the abscess extends upwards through a plane between the longitudinal muscles of the anal canal, rectum, and internal anal sphincter
*cephalad spread of an intersphincteric abscess toward levators will lead to a supra levator abscess. The transversalis fascia and the parietal peritoneum form the upper extent of the supralevator space. An upward extension of the abscess through a supralevator space may form an anterior abdominal wall abscess or rupture through the peritoneum into the peritoneal cavity
*internal sphincter helps prevent an intersphincteric abscess from bursting into the rectum by acting as a barrier
*typical horseshoe abscess or fistula is infralevator in location. Most of these originate in the infected anal gland, at or near the posterior midline on the dentate line
*infection spreads caudally to deep postanal space from an intersphincteric plane. Since the deep postanal space communicates with the ischiorectal fossae, an abscess may spread circumferentially through this or other intercommunicating spaces leading to a horseshoe abscess.
*pus extends and lies near the levator ani and its external sphincter complex junction. The abscess may extend anteriorly from a deep anterior anal space to involve the thigh, the labia, and the scrotum [17]. In neglected cases, multiple external openings may be present in the perineum.
*A patient with an intersphincteric abscess may present with pain during defecation. Tenesmus, sepsis, and throbbing lower abdomen pain or pelvic discomfort are usual symptoms in patients with supralevator abscess. Fever and leucocytosis may be present.
*Urinary retention and paralytic ileus are signs of an acute illness
*Erythema, induration, or fluctuance are present on local examination.
*Differential Diagnosis • Hidradenitis suppurativa • Thrombosed hemorrhoids • Skin furuncles • Herpes • HIV • Tuberculosis • Actinomycosis • Ulcerative colitis • Bartholin cyst • Syphilis If the abscess is associated with multiple fissures, skin tags, or concomitant fistula, it may suggest an underlying Crohn’s disease
PERINIAL ABSCESS
*culture demonstrates no bowel-derived organism, the chances of fistula formation are less
*If the enteric organisms are isolated from the culture, there is always a possibility of fistula being present. The most typical organisms isolated are E. coli, Klebsiella pneumonia, or Bacteroides species.