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2. Clubbing can be defined as the selective
bullous enlargement of the distal segments of
the fingers and toes due to proliferation of
connective tissue,
particularly on the dorsal surface
There is increased sponginess of the soft
tissue at the nail bed. It is also called
HIPPOCRATIC FINGERS,
DRUMSTICK FINGERS or
WATCH GLASS NAILS

3. Grade 1 – Fluctuation of the
nail bed.
Grade 2 – Obliteration of the
Lovibond angle.
Grade 3 – Parrot beak
appearance or drum stick
appearance
Grade 4 – Hypertrophic Osteo
Arthropathy (HOA)

4. Causes:
Clubbing is associated with diseases of the
lung, heart, GIT, endocrine system and
miscellaneous diseases
simple way of remembering few causes of
clubbing are:

5. C – Congenital Cyanotic Heart Disease, Cystic
fibrosis, Crohn’s disease, Cholangiolitic cirrhosis,
L – Lung abscess, Lipoid pneumonia,
U – Ulcerative colitis,
B – Bronchiectasis, Bronchogenic carcinoma,
B – Biliary cirrhosis,
I – Infective endocarditis, idiopathic pulmonary
fibrosis
N – Neoplasms of lung, liver, esophagus, small &
large bowel.
G – Grave’s disease (thyroid acropachy)

6. Neurogenic theory
a vagotomy causes a symptomatic improvement in
the HOA, thus allowing us to infer that a vagal
stimulus(from a tumour site) via neural reflexes
can lead to proliferation of connective tissue at
the distal extremities
This theory was unable to explain why conditions
like CCHD and aneurysms cause clubbing.

7. Humoral theory
Normally the lung throws out all the soluble
substances by inactivation
But in case of lung problems, these substances
reach the systemic circulation in the active state
and they stimulate the changes seen in HOA
(Prostaglandins, ferritin, bradykinin and growth
hormone)
However this theory suffered a setback because
normal levels of thee metabolites were found in
HOA cases

8. Role of platelets
Normally megakaryocytes and large platelets get
destroyed in the lung
In cases where these is a lung pathology or CCHD or right
to left shunts, these platelets escape and reach distal
extremities interact with the endothelial cells and release
platelet derived growth factor (PDGF) post activation.
PDGF and other mediators then activate the fibroblasts
and transforming growth factor β (TGF-β) which lead to
collagen production and connective tissue laying down
ultimately giving rise to clubbing and HOA
This theory is supported by the evidence that plasma
levels of von Willebrand factor were elevated in HOA
cases. Further platelet clumps were demonstrated in
infected heart valves, walls of aneurysms and valve grafts

9. Hypoxia
Hypoxia is suggested to be a stimulus for
HOA
Hypoxia leads to opening of deep arterio-
venous shunts and fistulae which increase
blood flow to the extremities and leads to
hypertrophy

10. Clinical methods to assess clubbing is done by
The obliteration of Lovibond angle can be
assessed clinically by looking tangentially to
observe for the angle between the cuticle and the
proximal nail. (Normal angle = 15o from the skin or
160-165o from the nail)

11. The nail bed fluctuation is elicited by
stabilising the finger between the index finger
of both the hands such that the nail can be
balloted between the two fingers. Now, either
by using the thumb at the distal margin of the
nail or by using one index finger the nail is
balloted to check for fluctuation

12. Schamroth’s sign:
Normally when the two fingers are held
together with the nails facing each other, a
diamond shaped space is seen at the level of
the proximal nail fold. Obliteration of this
space indicates clubbing and is called as
Schamroth’s +

14. Source
General Medicine Clubbing.htm