Bone Abstracts

Background: Syphilis remains a great imitator of myriad of clinical diagnosis. Congenital syphilis, though still uncommon, is on the rise once again. Recognition of syphilitic bone disease and its potential impact on growth is important for long term prognosis. We describe our experience of managing a child with congenital syphilis and multisite osteolytic lesions.

Presenting problem: A 6 week-old girl presented with a swollen and painful elbow with reduced movement, but was systemically stable. She had pallor, hepatosplenomegaly, erythematous skin plaques, clear nasal discharge and bilateral conjunctivitis. Born normally, she had developed florid maculopapular erythematous rash with vesicles and bullae in her groins and face. Initial differential diagnoses included osteomyelitis, and severe immunodeficiency.

Her investigations revealed anaemia, neutrophilia, raised inflammatory markers, normal bone marrow cytology and hypergammaglobulinemia. TORCH (congenital infection) screen confirmed positive syphilis serology, and dark ground microscopy revealed spirochetes in the skin lesions. Whole body MR scan and x-rays showed lytic abnormalities within the right elbow and acromioclavicular joints. Subsequent skeletal survey showed diffuse metaphyseal lucency suggesting osteochondritis, increased diaphyseal density and striations, with periostitis. These changes are consistent with secondary syphilitic bone disease.

Clinical management: Child was treated with intravenous benzyl penicillin sodium 1 00,000 units/kg per day in four divided doses for 14 days in accordance with international guidelines. In the following weeks, there was dramatic clinical improvement, with normalisation of the haematological and biochemical parameters. Her syphilis serology progressively improved and was negative at 18 months. Repeat skeletal survey at this stage revealed entirely normal long bones with no residual focal abnormalities of the growth plate, focal sclerosis or limb length discrepancy.

Discussion: Congenital syphilis has a broad spectrum of presentation. Radiologically, infants may have signs of osteochondritis with a distinctive ‘cat bite’ appearance. While antenatal screening facilitates early detection and treatment of maternal syphilis, congenital syphilis can potentially have devastating bone sequelae such as Clutton joints and sabre tibia with impact on growth, if left untreated.

Conclusion: Our experience suggests that prompt recognition and early vigorous treatment of this condition can lead to complete resolution of syphilitic bone lesions, promoting normal growth and development.

Disclosure: The authors declared no competing interests.