Anal abscess
Essentials
- Anal abscesses are treated surgically.
- Follow-up the patient to detect anal fistula.
Aetiology
- In 90% of the cases the disease is cryptoglandular, i.e. inflammation of the anal glands.
- 10% of the cases have another aetiology: e.g. Crohn’s disease, trauma, HIV, radiation therapy, neoplasia.
Symptoms
- An anal abscess causes severe acute pain, and often (but not always) fever.
- Difficulties in voiding can be associated with a deep abscess.
Investigations
- Inspection of the anus usually reveals the diagnosis: a tender mass is observed near the anus.
- Touch per rectum may be impossible because of the pain. Perineal palpation may reveal a painful mass in these patients.
- If needed, the diagnosis can be confirmed by perineal ultrasonography.
- The abscess may be located in the anal canal between the sphincter muscles (intersphincteric abscess), in which case it is palpable through digital rectal examination or visible by endoanal ultrasonograpy, CT or MRI.
- If the patient has several abscesses or if there is a suspicion of Crohn’s disease (Crohn’s disease) for some other reason, an ileocolonoscopy should be carried out after having treated the abscesses.
Treatment
- An anal abscess always requires surgical incision and drainage.
- General anaesthesia is necessary for clinical examination and sufficiently wide incision.
- The incision is performed in an operating theatre setting, and if a fistula tract is found, it can be treated simultaneously [Evidence Level: B].
- If a fistula was not found in the operation, the wound should still be monitored until it has healed. Up to 50% of the patients develop an anal fistula, which requires new operation.
Evidence Summaries
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Citation
"Anal Abscess." Evidence-Based Medicine Guidelines, Duodecim Medical Publications Limited, 2019. Evidence Central, evidence.unboundmedicine.com/evidence/view/EBMG/456113/all/_________Anal_abscess______.
Anal abscess. Evidence-Based Medicine Guidelines. Duodecim Medical Publications Limited; 2019. https://evidence.unboundmedicine.com/evidence/view/EBMG/456113/all/_________Anal_abscess______. Accessed October 14, 2024.
Anal abscess. (2019). In Evidence-Based Medicine Guidelines. Duodecim Medical Publications Limited. https://evidence.unboundmedicine.com/evidence/view/EBMG/456113/all/_________Anal_abscess______
Anal Abscess [Internet]. In: Evidence-Based Medicine Guidelines. Duodecim Medical Publications Limited; 2019. [cited 2024 October 14]. Available from: https://evidence.unboundmedicine.com/evidence/view/EBMG/456113/all/_________Anal_abscess______.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC
T1 - Anal abscess
ID - 456113
BT - Evidence-Based Medicine Guidelines
UR - https://evidence.unboundmedicine.com/evidence/view/EBMG/456113/all/_________Anal_abscess______
PB - Duodecim Medical Publications Limited
DB - Evidence Central
DP - Unbound Medicine
ER -