Makindo Medical Notes.com

About

• Sexually transmitted infection

Aetiology

• Caused by Calymmatobacterium granulomatis
• Also called Klebsiella granulomatis comb nov.

Clinical

• First sign of infection is usually a firm papule or subcutaneous nodule that later ulcerates. Four types of donovanosis are described classically
  • Ulcerogranulomatous is the most common variant; non-tender, fleshy, exuberant, single or multiple, beefy red ulcers that bleed readily when touched.
  • Hypertrophic or verrucous type, an ulcer or growth with a raised irregular edge, sometimes with a walnut appearance.
  • Necrotic, usually a deep foul-smelling ulcer-causing tissue destruction.
  • Sclerotic, with extensive fibrous and scar tissue.
• Genitals are affected in 90% of cases and the inguinal area in 10%. Extragenital cases occur in 6% of cases: sites include the lip, gums, cheek, palate and pharynx. Atypical cases are reported in children, usually affecting the facial region
• Lymphadenitis is uncommon. Dissemination is rare; secondary spread to liver and bone may occur and is usually associated with pregnancy and cervical lesions.
• The usual sites of infection are in men, the prepuce, coronal sulcus, frenum and glans penis and in women, the labia minora and fourchette. Lesions tend to grow more rapidly during pregnancy.
• Squamous cell carcinoma of the penis may both mimic and complicate donovanosis, and a biopsy should be done if antibiotics fail to affect resolution of ulcers

Investigations

• A rapid Giemsa can be used to stain tissue smears that should be prepared by rolling a swab firmly across the ulcer and rolling this swab evenly across a glass slide to deposit ulcer material. Characteristically, there are large mononuclear cells with intracytoplasmic cysts filled with deeply-stained Gram-negative Donovan bodies. These bodies are pleomorphic and sized 1-2 0.5-0.7 um. Depending on the stain used, bipolar densities and a capsule may be visible.
• Histologic examination for Donovan bodies is best done using Giemsa or Silver stains. The characteristic picture shows chronic inflammation with infiltration of plasma cells and polymorphonuclear leucocytes.
• Polymerase chain reaction (PCR) methods include a colourimetric detection method13,14 and a genital ulcer multiple PCR test using an in-house nucleic acid amplification technique with C. granulomatis primers. However, there are no commercial PCR tests for donovanosis currently available.
• Culture has only been accomplished in two labouratories in recent times and is not available routinely.
• Serology has been used in the past but is not reliable or routinely available.

Management

• First line: Azithromycin 1 g weekly or 500 mg daily orally
• Alternative regimens
  • Co-trimoxazole 160/800 mg bd orally: 1B19
  • Doxycycline 100 mg bd orally
  • Erythromycin 500 mg four times daily orally. Recommended in pregnancy
  • Gentamicin 1 mg/kg every 8 h parenterally can also be used as an adjunct if lesions are slow to respond
• Treatment in pregnancy: Erythromycin 500 m qds orally or Azithromycin could also be used: 1 g weekly
• Treatment of children: Azithromycin 20 mg/kg orally once daily
• Prophylactic antibiotics should be considered in neonates born to mothers with genital lesions; the recommended regimen is Azithromycin 20 mg/kg once daily for three days
• Partner management: In the absence of any reliable screening test and the long incubation period, all sexual contacts of cases in the last six months should be checked for possible lesions by clinical examination.

References

• 2018 UK national guideline for the management of donovanosis