CASE

A 9-month-old, full-term, fully immunized male child presented to the clinic with 3 months of oral lesions and nasal congestion. A single oral ulcer was initially noticed 3 months prior, which his mother had attributed to teething. Additional ulcers followed, but he did not have any constitutional symptoms, including fever. The child had normal growth parameters and was breastfeeding in addition to taking complementary foods. He was born to a 31-year-old, healthy, G1P0 mother via normal vaginal delivery at the 39th gestational week after an uncomplicated pregnancy including routine prenatal care throughout. Prenatal screening for human immunodeficiency virus, Treponema pallidum, Neisseria gonorrhoeae and Chlamydia trachomatis were negative during the first trimester and at the 32nd gestational week. The neonatal period was uneventful, and the child did not have any prior hospitalizations.

The infant’s vital signs included a temperature of 37ºC, heart rate of 143 beats/minute, respiratory rate of 40 breaths/minute and oxygen saturation of 100% in ambient air. His physical examination was unremarkable except for 3 shallow oral ulcers measuring around 0.5 × 0.5 cm on the tongue and significant nasal congestion. He did not have any teeth yet. He also did not have hepatosplenomegaly, rash or lymphadenopathy.

Complete blood count showed white blood cell (WBC) of 6.9 × 109/L with a differential of 68% lymphocytes, 20% neutrophils, 8% monocytes, 4% eosinophils, hemoglobin of 9.6 g/dL, platelet count of 420 × 109/L and alanine aminotransferase of 10 U/L.

Further family history and additional laboratory tests revealed the diagnosis.

DENOUEMENT

Upon a detailed family history, it was revealed that the mother had developed a discrete circular, maculopapular rash on her arms and a diffuse, scaly and faint macular rash on her anterior chest around her breasts 3 months after delivery. After evaluations by several providers and her partner’s disclosure of having asymptomatic and untreated syphilis, she was diagnosed with syphilis 5 months after delivery with reactive Rapid plasma reagin (RPR) titer 1:256. She had not noticed a primary syphilis chancre. Because her skin lesions and history were consistent with secondary syphilis, she was treated with a single dose of 2,400,000 U benzathine penicillin G intramuscularly. Her partner was also treated. At this time, the mother brought her child to his pediatrician; however, a syphilis test was deferred because of her negative screening tests during pregnancy. One month after the mother’s diagnosis and treatment, the baby’s first oral ulcer at the tip of the tongue was noticed.

Considering the mother’s recent diagnosis of secondary syphilis lesions on her arms and on the chest, we suspected syphilis with oral ulcers and snuffles in this infant. The child’s treponemal IgM/IgG screening test was positive, but the RPR was initially nonreactive, yet a Treponema pallidum particle agglutination assay test was reactive. We requested dilution of the RPR testing to rule out the prozone phenomenon. The RPR result was 1:256 after dilution.

The child was admitted to the hospital for congenital syphilis evaluation and treatment. Contact isolation precautions were placed since nasal secretions and oral lesions can be contagious. Lumbar puncture was performed and revealed a cell count of 3 WBC/ml, protein 21 mg/dL, glucose 51 mg/dL, nonreactive Venereal Disease Research Laboratory. Long bone radiographs, abdominal ultrasonography, and hearing and ophthalmologic examinations were all normal. HIV test was negative. The infant received 10 days of IV aqueous crystalline penicillin G 50,000 U/kg 4 times per day. His oral ulcers and snuffles resolved completely towards the end of treatment.

Syphilis is a sexually transmitted disease caused by Treponema pallidum. The number of syphilis cases decreased dramatically worldwide after the introduction of penicillin and diagnostic testing; however, in the last decade, cases have been increasing. The Centers for Disease Control and Prevention has reported 171,074 syphilis cases in 2021, a 68% increase since 2017 in the United States (US).1 In parallel with this trend in total syphilis cases, congenital syphilis rates are significantly up trending as well.1

Transmission of syphilis in the pediatric population is most often congenital in infants and sexually acquired in adolescents.2 The mode of acquired syphilis transmission is almost exclusively sexual contact.3 Sexual abuse is also another consideration for children with syphilis.4 Acquired syphilis by nonsexual contact is very rare in the postantibiotic era, although it was common in the early 1900s.5

In this case, we could not totally rule out congenital syphilis since the mother did not have a syphilis test around the time of delivery. However, the timing of the baby’s symptoms in relation to the mother’s symptoms (Fig. 1), completely negative congenital syphilis workup, and the fact that the index case in the family had sexual contact with the infected individual after delivery, strongly support acquired syphilis. We surmise that syphilis acquisition was through close skin-to-skin and oral mucosal contact with the mother’s secondary syphilis lesions during breastfeeding, along with contamination of the baby’s eating utensils and pacifier with the mother’s oral secretions. Upon follow-up evaluations in the pediatric infectious disease clinic, the infant continued to be asymptomatic, and RPR titers were 1:8 and 1:2 at visits 2 and 8 months after discharge, respectively.

FIGURE 1.:

Timeline of baby’s symptoms and diagnosis in relation to mother’s symptoms and diagnosis.

Syphilis in young children is almost exclusively caused by congenital transmission or sexual abuse. However, the nonsexual transmission of syphilis to infants from an infected caregiver with prolonged and repetitive contact, breastfeeding, sharing eating utensils, and handling certain objects such as a pacifier is a well-described entity.6 There was a special term for this form of syphilis transmission in the preantibiotic era: Syphilis Brephotrophica. Brephotrophica literally means nourishing baby, and it was used to describe syphilis transmission to infants through handling and feeding from an infected caregiver, especially from an infected wet nurse.7Syphilis Brephotrophica and other forms of nonsexually acquired syphilis acquisition were a common public health problem in the preantibiotic era; however, it is now a virtually forgotten form of syphilis transmission due to accessible testing and treatment and public health measures such as mandatory reporting to health authorities.8

In the postantibiotic era, there are few case reports in the medical literature regarding nonsexual syphilis transmission in children, and most were associated with feeding children premasticated foods.4,9 Moscatelli et al.9 from Argentina recently published the first nonsexually acquired syphilis study in the 21st century. In their retrospective study, they reported 24 patients with nonsexually acquired syphilis with a median age of 4.2 years and the youngest and the oldest being 1 and 17 years of age, respectively. Secondary syphilis skin manifestations were presenting symptoms in 19 of 24 patients, and 4 of them had oral lesions. Similar to our case, 5 of their patients received 10 days of IV penicillin treatment since they could not rule out congenital syphilis. The exact mode of transmission in nonsexually acquired cases was not provided in this study, although they mentioned all patients came from a crowded households with poor hygiene conditions.9

Potentially, we report the first nonsexually acquired pediatric syphilis case in the US in the last 30 years to our best knowledge based on our literature search.10 Our patient is also one of a few reported cases of Syphilis Brephotrephica in patients less than 1 year of age in the postantibiotic era.8 Although nonsexually acquired syphilis is rare, providers should be aware of this possibility, especially in infants with positive family history regardless of prenatal screening results.

REFERENCES 1. Centers for Disease Control and Prevention. The State of STDs in United States. 2021. Available at: https://www.cdc.gov/std/statistics/national-Aug2022.pdf. Accessed January 1, 2023. 2. Heston S, Arnold S. Syphilis in children. Infect Dis Clin North Am 2018;32:129–144. 3. Stoltey JE, Cohen SE. Syphilis transmission: a review of the current evidence. Sex Health 2015;12:103–109. 4. Dayal S, Sahu P, Aggarwal K, et al. Acquired syphilis in children: a retrospective study over two-and-a-half decades in a tertiary care center in northern India. Pediatr Dermatol 2020;37:311–315. 5. Ackerman AB, Goldfaden G, Cosmides JC. Acquired syphilis in early childhood. Arch Dermatol 1972;106:92–93. 6. Hofmann B, Schuppe HC, Ruzicka T, et al. Acquired syphilis II in early childhood: reappearance of syphilis brephotrophica. J Am Acad Dermatol 1998;38:638–639. 7. Thom BP. Syphilis. Lea & Febiger; 1922. 510 p. 8. Meyer GS. Occupational infection in health care. The century-old lessons from syphilis. Arch Intern Med 1993;153:2439–2447. 9. Moscatelli G, Moroni S, García Bournissen F, et al. Acquired syphilis by nonsexual contact in childhood. Pediatr Infect Dis J 2021;40:892–898. 10. Echols SK, Shupp DL, Schroeter AL. Acquired secondary syphilis in a child. J Am Acad Dermatol 1990;22:313–314.