Snapshot A 2-week-old infant boy is brought to the pediatrician by his parents. He was born to a 25-year-old G1P1 mother who admits that she was unable to make the majority of her prenatal appointments for various personal reasons. She has not heard of a Veneral Disease Research Laboratory (VDRL) test or rapid plasma reagin (RPR) test and does not believe that she received them during her pregnancy. She and the father of the baby both had multiple sexual partners. When questioned about symptoms experienced during her pregnancy, the woman recalls that she had a fever with swollen lymph nodes and a rash on her hands and feet. A physical examination is performed on the infant, who is pale and mildly irritable. Skin examination reveals the finding seen in the image. Introduction Overview syphilis is caused by the spirochete Treponema pallidum cases of syphilis in children are typically congenital, acquired via intrapartum transmission Epidemiology 23 per 100,000 live births in the US ETIOLOGY Pathophysiology T. pallidum spirochetes are transmitted transplacentally from the infected mother into the bloodstream of the fetus spirochetes spread through the bloodstream of the fetus to the organs nearly 100% of infants born to infected mothers get the disease transmission usually occurs after the first trimester Presentation Symptoms early manifestations occur within the first 2 years of life fever blood tinged nasal secretions and snuffles hemolytic anemia maculopapular rash involves palms and soles followed by desquamation wart-like mucosal lesions hepatosplenomegaly osteochondritis may be so painful that the infant refuses to move the affected extremity saddle nose secondary to syphilitic rhinitis late manifestations painless symmetrical joint swelling saber shins anterior bowing of the tibia Hutchinson teeth rhagades peri-oral fissures, cracks, or scars in the skin Physical exam mucocutaneous lesions desquamating rash that may involve the palms and soles Hutchinson triad peg-shaped upper central incisors deafness interstitial keratitis Studies Dark-field microscopy shows spirochetes in tissue sample or lesions Non-treponemal serologic tests RPR and VDRL tests non-treponemal tests 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, and pregnancy) Treponema-specific tests fluorescent treponemal antibody absorption (FTA-ABS) treponemal test using T. pallidum antigen with high sensitivity (85% in primary and 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 Parvovirus B19 infection key differentiating factor classic "slapped cheek" rash no skeletal abnormalities Pediatric HIV infection key differentiating factor positive HIV DNA PCR results Pediatric HSV infection key differentiating factor gingivostomatitis and herpetic whitlow are common dermatologic findings Treatment Medical IM penicillin indications administered in all stages of syphilis if penicillin allergy, patient should be desensitized and treated with penicillin doxycycline and tetracycline indications primary syphilis patients in whom desensitization to penicillin is not feasible Complications Jarisch-Herxheimer reaction major complication of treatment for syphilis abrupt onset of fever, chills, myalgias, headache, tachycardia, and hyperventilation incidence up to 90% of patients with secondary syphilis