Treatment of Syphilis During Pregnancy

Penicillin is the drug of choice for treating all stages of syphilis. Parenteral rather than oral treatment has been the route of choice as the therapy is supervised and bioavailability is guaranteed. Most women treated during pregnancy will deliver before their serological response to treatment can be assessed definitively. Neonates born to such women should be evaluated for congenital syphilis. The UK national guidelines for the treatment of early syphilis during pregnancy are described as follows:
First-line therapy: intramuscular (i.m.) procaine penicillin 750 mg daily for 10 days. If it is not possible to give daily procaine penicillin on the weekend, then either long-acting procaine penicillin in aluminium stearate, 2 million units (MU) or long-acting benethamine penicillin 1.2 MU should be given IM on the Friday.
Patients with penicillin allergy: erythromycin 500 mg four times a day should be given for 14 days. Alternatively, azithromycin 500 mg should be given daily for 10 days. In addition to this, examination, tests, and treatment of all babies at birth should be carried out. Desensitization to penicillin may be considered, followed by the first-line treatment. Mothers treated with erythromycin or azithromycin may be considered for retreatment with doxycycline after delivery and when breast-feeding is stopped.
Patients suspected of non-compliance: benzathine penicillin 2.4 MU i.m. on Days 1 and 8.
Penicillin Reactions
Approximately 5–10% of pregnant women with syphilis report a history of penicillin allergy. The Jarisch–Herxheimer reaction is an acute response that may occur after treatment for acquired early syphilis. It occurs in up to 45% of pregnant women and consists of fever, chills, myalgia, headache, hypotension, tachycardia, and transient accentuation of the cutaneous lesions.[6] It typically begins within several hours of treatment and resolves within 24–36 h. The release of T. pallidum lipoprotein, which possesses inflammatory activity from dead or dying organisms, is implicated as a likely inducer of this phenomenon. In pregnant women, the Jarisch–Herxheimer reaction can cause uterine contractions and precipitate labour. This is possibly mediated secondarily by prostaglandins as the concentrations are increased during reactions.[6,10]
Syphilis and HIV
Syphilis commonly co-exists in patients with HIV (prevalence is 14–36%). All HIV-infected patients under regular follow-up should have syphilis serology documented at baseline and subsequently 12 monthly thereafter. HIV-infected patients with early syphilis have an increased risk of neurological involvement. Features of syphilis in HIV include: generalized lymphadenopathy; splenomegaly; hepatitis; skin rashes, alopecia or both; oral manifestations; cognitive impairment; meningitis; cranial nerve palsies; myopathies; and uveitis.
Anaesthetic Considerations
There is little specific advice available on the anaesthetic management of patients with syphilis. Universal precautions should be considered at all times when anaesthetizing patients with syphilis. Accidental transmission of syphilis involves direct contact through a small skin abrasion. It has been reported under the following circumstances: doctors and nurses who have examined a syphilitic lesion without wearing gloves; laboratory workers by needle stick injury when inoculating treponemes into rabbits, or during isolation or purification procedures; and patients being transfused with blood from a donor suffering from early syphilis.
Infection by blood transfusion is rare in the UK because screening tests are routinely performed for evidence of donor infection with syphilis. After storage in blood for more than 4 days at 4oC, spirochetes are non-viable. The risk of accidental infection by infected blood is highest when fresh heparinized blood is used. Such blood is used for exchange transfusion in neonates. Cutaneous lesions of the breast and nipples carry a risk of transmission through breast feeding. After needle-stick injury, the risk of transmission is very low. Antibiotics are not routinely recommended for needle-stick injuries; however, each wound should be assessed individually by the relevant healthcare professionals.
There is no additional risk with general anaesthesia. There is a single report of a 73-year-old woman with late congenital pharyngo-laryngeal syphilis, who presented with a potentially difficult intubation during the induction of general anaesthesia.[11] Syphilis poses no specific problems for regional blockade. The three main manifestations of late syphilis (neuro-, cardiovascular, and gummatous syphilis) can have a wide range of presentation. It is prudent to assess and document all existing signs and symptoms (including neurological examination) in the anaesthetic record. There is no evidence to suggest that regional blockade can affect the extent or likelihood of neurosyphilis. The lesion in tabes dorsalis is concentrated on the dorsal spinal roots and dorsal columns of the spinal cord, most often at the lumbosacral and the lower thoracic region. There have been reports that spinal anaesthesia induces severe lightning pain in the lower limbs of patients with phantom limb pain, tabes dorsalis, or causalgia. The exact mechanism of this phenomenon is controversial. Some hypothesize that complete loss of sensory input after spinal anaesthesia may decrease the level of inhibition and increase the self-sustained neural activity.
Options for delivery include elective Caesarean section because it is associated with less vertical transmission. When considering postoperative analgesia, those techniques that do not expose staff to needle-stick injury should be favoured.