Prevalence, aetiologies and significance of clubbing in a department of general internal medicine

BackgroundClubbing remains an amazing clinical sign. Its strong association with serious disease is still a clinical enigma. Moreover, the significance of diagnosing clubbing is not well established. The aim of our study was to evaluate prevalence, aetiology and clinical significance of clubbing in a department of general internal medicine.Patients and methodsDuring one year (1511 admissions), all patients with digital clubbing assessed by determining ratio of the distal phalangeal depth (DPD) to the interphalangeal depth (IPD) and with the presence of Swamroth sign were included. Fifteen patients were diagnosed with clubbing (10 males and 5 females). They underwent complete physical examination, pulmonary CT-scan, bone scintigraphy, blood gas analysis and were compared with 86 matched controls.ResultsAetiology were renal cell carcinoma, pulmonary arteriovenous malformation, AIDS, inflammatory pseudo-tumour of the lung, adenocarcinoma of unknown origin in one case and in one case, Pet-scan suspected neoplasia but histology was not obtained. In 9 cases, no aetiology was found. Bone scan was normal in 14 cases and revealed periostitis in one case (idiopathic clubbing). Compared to control group, there was no difference in blood gas analysis but emphysema was more often present in patients with clubbing (p < 0.01). No patient without aetiology developed cancer in the one year follow-up.Conclusion:Clubbing is present in 1% of admission in a department of general internal medicine and is associated in nearly 40% with serious disease. In 60% of cases, aetiology is not identified but follow-up do not disclosed cancer.