Early syphilis (primary, secondary and early latent syphilis of not more than two years’ duration) in pregnant women. If benzathine penicillin is not available, WHO suggests:

• procaine penicillin 1.2 million units intramuscularly once daily for 10 days.

In rare situations when benzathine or procaine penicillin cannot be used (e.g. due to confirmed penicillin allergy, which occurs in less than 3% of the population, and where penicillin desensitization is not possible) or are not available (e.g. due to stock-outs), WHO suggests one of the following options with caution and enhanced follow-up:

• ceftriaxone 1 g intramuscularly once daily for 10–14 days; or
• erythromycin 500 mg orally four times daily for 14 days.