Clubbing and hypertrophic osteoarthropathy: insights in diagnosis, pathophysiology, and clinical significance.
BACKGROUND
Digital clubbing and hypertrophic osteoarthropathy (HOA) form a diagnostic challenge. Subtle presentations of clubbing are often missed. The underlying pathophysiology remains unclear. Establishing a differential diagnosis based on nonspecific signs can be cumbersome. Finally, the prognostic value of clubbing and HOA remains unclear.


OBJECTIVE
This article reviews clinical criteria and pathophysiology of clubbing and HOA. A diagnostic algorithm is proposed, based on etiology and current insights. The prognostic impact on associated diseases is discussed.


METHODS
The Internet databases Medline and Embase were searched. Articles were selected based on relevance of abstract, article type and impact of the journal.


RESULTS
Diagnostic criteria include Lovibond's profile sign, distal/interphalangeal depth ratio and Schamroth's sign. Three pathophysiological causes of clubbing can be distinguished: hypoxia, chronic inflammation and aberrant vascularization. A prominent role for vascular endothelial growth factor is suggested. Associated symptoms and clinical signs should guide the initial diagnostic evaluation. Finally, clubbing is a negative prognostic factor in certain pulmonary disorders, including cystic fibrosis.
a Faculty of Medicine , KU Leuven University , Belgium.
Jasper
J
Callemeyn
b Department of Internal Medicine , Sint-Rembert Hospital Torhout , Belgium.
Peter
P
Van Haecke
c Department of General Internal Medicine , University Hospital Leuven , Belgium.
Willy E
WE
Peetermans
c Department of General Internal Medicine , University Hospital Leuven , Belgium.
Daniel
D
Blockmans
D006801:Humans; D010004:Osteoarthropathy, Primary Hypertrophic / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology; D010005:Osteoarthropathy, Secondary Hypertrophic / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology; D011379:Prognosis
Algorithm; Digital clubbing; Lung cancer; Osteoarthropathy; Secondary hypertrophic; Vascular endothelial growth factor