Early Congenital Syphilis: Recognising Symptoms of an Increasingly Prevalent Disease

Congenital syphilis (CS) is an infectious disease resulting from transplacental transmission of Treponema pallidum spirochetes from an infected mother to fetus during pregnancy. While uncommon, CS has shown an increased incidence in Canada and the United States since 2001 and 2012, respectively.

We present the case of a 5-week-old female infant with blistering rash on the palms and soles. The infant displayed decreased movement of the left upper extremity, clinically consistent with Parrot pseudoparalysis. Cutaneous involvement was limited to few tan crusted papules on the palms and soles. Mother reported a "false-positive" result of rapid plasma reagin (RPR) testing at 31 weeks. Cerebrospinal fluid studies of the infant resulted with positive Venereal Disease Research Laboratory (VRDL) test and positive microhemagglutination assay (MHA-TP). Histopathology of a crusted papule revealed a lichenoid infiltrate composed of lymphocytes, histiocytes, and plasma cells. Immunohistochemical staining for T pallidum was negative. The patient completed treatment with a 10-day course of intravenous penicillin.

While CS is largely considered a historic entity, it has been increasing in incidence in the United States since 2012 and in Canada since the early 2000s. Diagnosis of CS can be difficult as infants may be asymptomatic or present with nonspecific signs. This case highlights the presentation of minimal cutaneous involvement as well as skeletal involvement after birth. RPR testing may result in false negatives or indeterminate results, further complicating diagnosis. Given these difficulties in screening and the increasing incidence of CS, clinicians may need to refamiliarise themselves with its clinical findings.