We present the clinical picture of primary hypertrophic osteoarthropathy in five children, including two pairs of siblings, who were examined in the Paediatric Rheumatology Department (National Institute of Geriatrics, Rheumatology and Rehabilitation, NIGRIR, in Warsaw, Poland) due to pain and features of arthritis. In the course of the diagnosis of joint ailments, patients were diagnosed with primary hypertrophic osteoarthropathy based on the clinical picture and following a complete diagnosis of possible secondary causes of the disease. All patients were referred for genetic diagnosis (test results were not available until the publication of this description). PGE2 levels in serum and urine were not determined.
The detailed characteristics of clinical symptoms and test results are presented in Table 1.
The reason for the admission of all five described children to the Paediatric Rheumatology Department was pain and swelling of the joints the patients had experienced from the first years of life (i.e. from the age of 2 years). Their diagnostics was started between the ages of 2 and 7 years.
The complaints concerned knee joints in all patients, in 3 out of 5 patients additionally ankle joints, and in one the wrists. Physical examination revealed swelling or widening of the outlines of the knee and ankle joints in all patients and of the elbows in 2 of 5 cases. Limited joint mobility was found in the knee joints in 3 children, in the elbows in 2 children, and in isolated cases in the hip and wrist joints. Local atrophy of the quadriceps muscles of the thighs was observed in 2 children (Fig. 1).
Physical examination revealed clubbed fingers and toes - a symptom which, according to the history of all children, appeared in the first months of life. Only in 2 cases was thickening of the skin of the soles of the feet observed.
The interview showed that in early childhood, 2 children had wide cranial sutures. Radiological examinations revealed disturbances in the mineralization of the skull bones, dilatation and uneven outline of the cranial sutures, in 1 case with visible additional (Wormian) bones. Other changes typical of osteoarthropathy include: hyperhidrosis described in 4 of our patients, seborrhoeic lesions in 2 cases, and large hands and feet in 3 cases. There was no typical scalp hypertrophy.
All patients had normal markers of inflammation. The blood counts were normal in 4 patients, and in 1 girl (patient No. 1) mild microcytic anaemia occurred periodically. No patient was found to have rheumatoid factor or the HLA-B27 antigen. In 2 cases, the presence of antinuclear antibodies (ANA) was found (patient No. 5. 1 : 160 anti-Golgi antibodies, speckled ANA pattern; patient No. 1. 1 : 320 with nucleolus ANA pattern, without the presence of antibodies specific for systemic connective tissue diseases). In the course of rheumatological diagnostics, Borrelia burgdorferi, Yersinia, viral hepatitis and tuberculosis infections were excluded.
Radiological examinations in 2 patients showed typical features of periosteal bone formation, which were visualized in the shafts of the phalanges, radial, ulna, tibia, and fibula (in one of the patients - patient No. 4 - inward bending of the fibulae was also described). Additionally, in one of these patients (patient No. 4) hypertrophy of the right tarsal, heel and ankle bones was described. In 2 patients radiological imaging revealed acro-osteolytic lesions of the bones of the feet. Ultrasound imaging in 2 patients showed inflammatory changes in the synovial membrane: thickening/hyperplasia, but no signs of hyperaemia. Other lesions described in the ultrasound imaging of the joints in individual cases include tenosynovitis, thickening of the subcutaneous tissue and inflammation of Hoffa's fat pad.
All patients were treated with NSAIDs, which alleviated the pain but did not completely resolve any complaints or symptoms. In 2 cases, intraarticular glucocorticosteroids were used, without any evident improvement. In one of the patients (patient No. 1) with primary hypertrophic osteoarthropathy and previous diagnosis of juvenile idiopathic arthritis treated with methotrexate and sulfasalazine, the diagnosis was revised. Treatment was discontinued without worsening of symptoms.