CLUBBING

Added: 2026-05-15

[00:00:00]Hello everyone.

[00:00:01]Today we will be discussing about clubbing.

[00:00:04]Clubbing by definition is the bulbous enlargement of the distal segments of fingers and toenails due to a proliferation of soft tissue between the proximal finger and the angle of nail bed.

[00:00:15]Normally, the Lovibond angle, which is the angle between the nail bed and the proximal finger, is 160° or less, as we can see over here. However, in a patient of clubbing, this angle increases to more than 180°, as we can see in this image which shows a club finger.

[00:00:32]Now, we will be discussing the pathophysiology of clubbing.

[00:00:35]The most accepted theory is the megakaryocyte theory.

[00:00:39]Normally, megakaryocytes and giant platelets in the bone marrow enter the lungs and get fragmented there and there itself.

[00:00:45]However, due to certain manifestations, such as cardiac manifestations and lung manifestations, it will lead to the aggregation of these platelets in the peripheral circulation.

[00:00:54]These platelets then go into the digital circulation and get trapped.

[00:00:58]This leads to secretion of uh PDGF, that is platelet-derived growth factor, and other cytokines in the digital circulation, which will lead to proliferation of the angle of nail bed.

[00:01:09]These manifestations which we can lead to this condition include cyanotic heart disease that will cause uh the platelets to bypass lungs due to the shunting of blood.

[00:01:17]Or certain lung pathologies or diseases, such as tumors or infections, fibrosis, will lead to lung function getting deranged, so ineffective fractionization of these platelets will occur.

[00:01:29]Now, we will be discussing the grades of clubbing.

[00:01:32]In total, there are five.

[00:01:34]Grade one is fluctuation and softening of the nail bed.

[00:01:37]Grade two is the loss of Lovibond angle, as we had previously discussed.

[00:01:41]Grade three is the characteristic parrot-beak appearance that refers to increased convexity of the nail bed, as we can see in this image.

[00:01:49]Grade four is the drumstick appearance.

[00:01:52]Here, the nail gets a drumstick appearance due to bulbous enlargement of the nail bed.

[00:01:57]Grade five is hypertrophic osteoarthropathy.

[00:02:00]In this, in addition to digital clubbing, patient also shows periosteal involvement. That is uh bone growth in the fingers.

[00:02:10]Uh now we'll be learning about examination of clubbing.

[00:02:13]Firstly, on inspection uh in this patient we can see that there is increased convexity of the nail bed.

[00:02:25]Now, putting the index finger at the eye level we can see that there is loss of Lovibond angle in this patient. That is the angle at the nail bed increases uh more than 180°.

[00:02:39]Now, uh palpation findings. We'll be demonstrating fluctuation and Shamroth's sign in this patient.

[00:02:45]Now, firstly, coming to fluctuation test.

[00:02:58]As we can see, fluctuation test is present in this patient.

[00:03:01]Now, what is the Shamroth's sign?

[00:03:04]Normally, between two fingers we will see a diamond-shaped space.

[00:03:09]And this is normally present in all individuals. However, this space will be lost in a patient with clubbing.

[00:03:21]As we can see, in this patient there is loss of this space. Suggestive of positive Shamroth's sign.

[00:03:28]So now, we'll be looking at interphalangeal thickness to demonstrate clubbing.

[00:03:33]Uh this is one of the most objective methods of looking at clubbing. However, it is rarely used in clinical practice.

[00:03:39]For this, we'll be using a vernier caliper.

[00:03:42]Uh in a patient who Normally, someone who does not show clubbing, we will see that the distal interphalangeal joint upon interphalangeal joint ratio is less than one. However, in a patient with clubbing, it will be more than one.

[00:03:56]So, now firstly, you'll be measuring the interphalangeal thickness in this patient.

[00:04:08]As you can see, it is roughly 12.6 mm.

[00:04:15]Now, we'll be measuring the distal interphalangeal thickness.

[00:04:28]As you can see, it is 12.9 mm.

[00:04:32]When we will we will be calculating the distal interphalangeal upon interphalangeal ratio, it will come out to be more than one, which means it is suggestive of clubbing in this patient.

[00:04:41]Uh now, we will be demonstrating hypertrophic osteoarthropathy in this patient. As you can see, this patient has significant digital clubbing. Uh along with it, if we see uh swelling near the wrist joint, then it will be suggestive of periosteal involvement.

[00:04:58]As we can see, there's swelling present in the wrist joint of this patient bilaterally.

[00:05:04]Also, when we look near the tibia, uh at the ankle joint, we can see significant swelling suggestive of periosteal involvement.

[00:05:16]Now, coming to causes of clubbing, system-wise, respiratory causes are lung cancer, lung abscess, interstitial lung disease, bronchiectasis, cystic fibrosis.

[00:05:29]Cardiac causes are cyanotic congenital heart disease, in infective endocarditis, and Eisenmenger syndrome.

[00:05:38]Now, we will look for gastrointestinal causes.

[00:05:44]IBD, liver cirrhosis, primary biliary cholangitis, and hepatocellular carcinoma.

[00:05:51]Miscellaneous causes are neurogenic tumor, Grave's disease, and malignancy.

[00:05:58]Now, come to special types of clubbing.

[00:06:01]First, unilateral clubbing.

[00:06:04]Where there is a clubbing only in one arm or one hand.

[00:06:09]Causes: cervical rib, subclavian artery aneurysm, and chronic hemiplegia.

[00:06:15]Another type is unidigital clubbing.

[00:06:18]Where there is a clubbing only of single digit.

[00:06:22]Causes: trauma or rarely median nerve palsy.

[00:06:30]Differential clubbing.

[00:06:32]Where there is a clubbing only in lower limb, where upper limbs are normal.

[00:06:38]Causes: PDA with reversal of shunt.

[00:06:43]When the ductus arises below the origin of left subclavian artery.

[00:06:48]Rarely, there is a clubbing in left upper limb, and bilateral lower limb, and right upper limb is spared.

[00:06:58]Cause is when the ductus arises just before the origin of left subclavian artery and after brachiocephalic artery.

[00:07:08]Another type is reverse differential clubbing.

[00:07:12]Where there is a clubbing in upper limbs, and lower limbs are normal.

[00:07:17]Cause is PDA with transposition of great arteries with reversal of shunt.

[00:07:24]Thank you.