Hidden syphilis

Latent syphilis is defined as the period after infection with T. Pallidum, when the patient has no signs of the disease, but positive serological reactions are observed.

Patients with latent syphilis, as well as patients with a duration of disease of no more than 1 year, are classified as patients with early latent syphilis. Early latent syphilis is diagnosed if, during the previous year, patients:

• documented seroconversion was observed,
• the symptoms and signs of primary or secondary syphilis,
• were sex with partners who had primary, secondary or latent syphilis.

Almost all other patients with unidentified duration of latent syphilis should be treated as patients with late latent syphilis. The titres of non-treponemal serology tests are higher for early latent than for late latent syphilis. However, one should not use only the values of non-treponemal test titers for a reliable difference between early latent syphilis and late latent syphilis. Patients who do not show signs of early latent syphilis should also be treated as patients with late latent syphilis, without taking into account the levels of non-treponemal responses. All sexually active women with positive non-serous serological tests should undergo an internal vaginal examination in order to assess mucosal lesions before the syphilis stage is established. All patients with syphilis should be tested for HIV.

[1], [2]

Treatment of latent syphilis

Treatment of latent syphilis is aimed at preventing the development or progression of late complications. Although clinical experience confirms the effectiveness of penicillin for the treatment of this form of syphilis, there is a small amount of data on the choice of a specific treatment regimen. There is also little data on the use of drugs of the nonpenicillin series.

Recommended treatment regimens for latent syphilis in adults

These regimens are used in patients without allergies and with normal CSF values (if such a study was conducted).

Early latent syphilis

Benzathine penicillin G 2.4 million units IM in / m once

[3], [4], [5], [6], [7], [8],

Late latent syphilis or latent syphilis of unknown duration

Benzathine penicillin G, total 7.2 million units, is administered 3 times

For 2.4 million units IM in / m with a break in 1 week.

Recommended treatment of latent syphilis in children

After the neonatal period in children diagnosed with syphilis, a CSF study should be performed to exclude neurosyphilis, as well as a thorough examination of the medical history to determine whether syphilis is congenital or acquired (see Congenital Syphilis). Older children with acquired latent syphilis are evaluated as adults and they are given appropriate treatment regimens recommended for children (see Sexual harassment of children or rape). These schemes are used in children with acquired syphilis and normal CSF, not having allergies to penicillin.

Early latent syphilis

Benzathine penicillin G, from 50,000 units / kg IM to adult dosage

2.4 million units once Late latent syphilis or latent syphilis of unknown duration

Benzathine penicillin G, from 50,000 units / kg IM to adult dosage 2.4 million units 3 times with a break of 1 week (total from 150,000 units / kg to an adult dose of 7.2 million units).

[9],

Other management of patients with latent syphilis

All patients with latent syphilis should be examined for signs of tertiary syphilis (aortitis, neurosyphilis, gumma and iritis). In patients with syphilis, if one of the following criteria is present, the CSF should be examined before treatment:

• Neurological or ophthalmic symptoms or signs;
• Other evidence of active tertiary syphilis (eg, aortic, gum, iritis);
• Ineffective treatment;
• HIV infection in combination with late latent syphilis or syphilis with unknown duration).

Under certain circumstances, and also at the request of the patient, it is possible to perform a CSF study and other patients who do not meet the above criteria. If the results of the CSF test indicate abnormalities characteristic of neurosyphilis, the patient should be treated with neurosyphilis (see Neurosyphilis). All patients with syphilis should be tested for HIV.

Follow-up

Quantitative non-treponemal serology tests should be repeated 6 and then 12 months later. There is a limited amount of data on the response to treatment in patients with latent syphilis. If the titres are increased 4-fold or if the initially high titers (t1: 32) do not decrease at least 4-fold (two dilutions) within 12-24 months, or the patient develops symptoms or signs characteristic of syphilis, the patient should to be examined for neurosyphilis and appropriately treated repeatedly.

[10], [11], [12], [13],

Special Remarks

Allergy to penicillin

Men and non-pregnant women with an allergy to penicillin should be treated according to the following schemes.

[14], [15], [16], [17], [18], [19]

Recommended schemes

Doxycycline 100 mg orally 2 times a day

Or Tetracycline 500 mg orally 4 times a day.

Both drugs are used for 2 weeks, if it is known that the duration of infection is more than 1 year; in all other cases - within 4 weeks.

Pregnancy

Pregnant patients with penicillin allergy should be treated with penicillin after desensitization (see Management of patients with penicillin allergy and Syphilis during pregnancy).