Snapshot A 7-year-old boy presents to the pediatric clinic complaining of painless swelling of the left knee joint for the past three days. He reports that bright light has also been bothering him lately. The synovial fluid is found to be sterile, and a diagnosis of synovitis is recorded. On physical exam, the child is noted to have a saddle nose, peg-shaped upper central incisors, and a maculopapular rash. Eye exam reveals interstitial keratitis. It is noted during the exam that the child has difficulty hearing. Introduction Infection caused by the spirochete Treponema pallidum Primarily spread via intrapartum transmission nearly 100% of infants born to infected mothers get the disease transmission usually occurs after the first trimester TORCH infection (Toxoplasmosis, Other [syphilis], Rubella, CMV, Herpes) Results in both early and late manifestations of disease in the child Presentation Symptoms early manifestations occur within the first two years of life and include fever blood tinged nasal secretions and snuffles hemolytic anemia maculopapular rash followed by desquamation of hands and feet wart-like mucosal lesions hepatosplenomegaly (elevated LFTs) osteochondritis so painful that the infant refuses to move the affected extremity saddle nose secondary to syphilitic rhinitis late manifestations include mainly skeletal in nature painless symmetrical joint swelling saber shins anterior bowing of the tibia Hutchinson's teeth rhagades peri-oral fissures, cracks, or scars in the skin Physical exam notable for Hutchinson's triad peg-shaped upper central incisors deafness interstitial keratitis Evaluation Dark-field microscopy shows spirochetes in tissue sample or lesions VDRL/RPR non-treponemal test with moderate sensitivity (60-75%) and specificity (85-99%) main issue is that it can yield many false positives (i.e., cross-reactivity with viruses, SLE, rheumatic disease, tuberculosis, pregnancy) FTA-ABS treponemal test using T. pallidum antigen with high sensitivity (85% in primary; 100% in other stages) and specificity (96%) used as secondary diagnostic test T. pallidum particle agglutination test (TPPA) easier to use than FTA-ABS with similar sensitivity and specificity Differential Other TORCH infections, drugs, viruses, and diseases (i.e., SLE, leprosy, and rheumatic disease) resulting in VDRL false positives Treatment Medical management IM penicillin administered in all primary and secondary infections tetracycline or doxycycline for two weeks given to penicillin allergy patients Prognosis, Prevention, and Complications Prognosis fetal/prenatal death occurs in 40% of cases Prevention screen and treat infected mothers Complications multiple, congenital deformities and deficiencies as described above; death