Clubbing is bulbous enlargement of soft parts of the terminal phalanges with both transverse and longitudinal curving of the nails. The swelling of the terminal phalanges in clubbing occurs due to interstitial edema and dilation of the arterioles and capillaries.
Clubbing develops in five steps:
1. Fluctuation and softening of the nail bed (increased ballotability)
2. Loss of the normal <165° angle (“Lovibond angle”) between the nailbed and the fold (cuticula)
3. Increased convexity of the nail fold
4. Thickening of the whole distal (end part of the) finger (resembling a drumstick)
5. Shiny aspect and striation of the nail and skin
Causes of Clubbing
Pulmonary
- Bronchogenic carcinoma
- Lung abscess
- Bronchiectasis
- Tuberculois with secondary infection
- Diffuse fibrosing alveolitis
Cardiac
- Infective endocarditis
- Cyanotic heart disease
- Congenital heart disease
Alimentary
- Ulcerative colitis
- Crohn’s disease
- Cholangiolitic cirrhosis
Endocrine
- Iatrogenic myxedema
- Exophthalmic ophthalmoplegia
- Acromegaly
Miscellaneous
- Hereditary
- Idiopathic
- Unilateral: Pancoast tumor, subclavian and innominate artery aneurysm
- Unidigital- traumatic or tophi deposit in gout
- Only in the upper limbs in heroin addicts due to chronic obstructive phlebitis
Grades of Clubbing
Grade I: Softening of nail bed
Grade II: Obliteration of the angle of the nail bed
Grade III: Swelling of the subcutaneous tissues over the base of the nail causing the overlying skin to become tense, shiny and wet and increasing the curvature of the nail, resulting in parrot beak or drumstick appearance.
Grade IV: Swelling of the fingers in all dimensions associated with hypertrophic pulmonary osteoarthropathy causing pain and swelling of the hand, wrist etc, and radiographic evidence of subperiosteal new bone formation.
Mechanism
The exact mechanism is not known. It is believed that the stimulus for clubbing is hypoxia. Hypoxia leads to opening up of deep arteriovenous fistulas which increase the blood supply of the fingers and toes causing it to hypertrophy.
Another hypothesis is that when reduced ferritin in venous blood escapes oxidation in the lungs and enters the systemic circulation., it causes dilation of arterio-venous anastomosis and hypertrophy of the terminal phalanx resulting in clubbing.
Pseudoclubbing
In hyperparathyroidism excessive bone resorption may result in disappearance of the terminal phalanges with telescoping of soft tissues and a drumstick appearance of the finger resembling clubbing. However, the curvature of the nail is not present.
Schamroth’s test or Schamroth’s window test
This test was originally demonstrated by South African cardiologist Dr Leo Schamroth on himself and is a popular test for clubbing.
When the distal phalanges (bones nearest the fingertips) of corresponding fingers of opposite hands are directly apposed (placed against each other back to back), a small diamond-shaped “window” is normally apparent between the nailbeds.
If this window is obliterated, the test is positive and clubbing is present.
Hi Medicare,
I am Jagadish from Bangalore, I have been searching for the future of clubbing of finger patients, who are reportedly perfect from all tests except clubbing. I have clubbing of fingers but I am perfectly normal. I have underwent all the tests to check whether I have heart or lung or intestinal problem. All test report say that I am normal. So can you please tell me what may happen in the future. Or what might occur or develop.
I would be very grateful to the team of medicare if you could kindly provide me the guidance
Regards
Jagadish
Jagdish,
Idiopathic or primary clubbing [where no cause can be found] is known. If you have that and no associated problem then there should not be any cause of further concern.
Just to be extra cautious, get yourself examined on regular intervals.
i m MBBS student;studying in prefinal year.i m confused about the grading of clubing.
What is the confusion, Sneh?
Hello Medicare,
I would like to ask how can clubbing can present either in fingers or toes. Is the involvement of the toes indicate severity of the disease or its indicate different diagnosis? From what i know its indicate different diagnosis, as in vascular problem (eg. PDA, infected AAA) they will present with both fingers and toes but for lung origin it will present at fingers only. is that true? or nay further explanation..
Thank you for your concern..(^_^)
Regards,
Rafiza
i am one of medical student in ETHIOPIAN university and i am confused how clubbing is happen? i.e the pathophysiology of clubbing.
hai medicare
i had a small question
and my question is 1. patient with adrenal insuffeciency have greatly increased sesitivity to smell ? ( if so why n how)
2. what are all the tested to be taken by the patient with different grades of clubbing?
Hi!
Its Medcare.
I did not get your question. Are you asking from patient,s point of view or want to have more knowledge of the tests for clubbing.
I found this interesting but not an effective article. I’m a 7 year lung cancer survivor. Before I went into surgery, my PCP asked to look at my fingers and toes. He told me that I had digital clubbing which was a sign that I had a tumor in my body. He was speachless when I asked him why the medical profession did not tell people to monitor this condition…like women are told to look for lumps in their breast. My wife asked me, three months before my doctor said I had lung cancer, why my feet looked so weird. I found out later. I think the medical profession is totally irresponsible as regards this issue. I told some cancer advocacy groups about this phenomenon and none of them were aware of it and what it could mean as regards cancer. It’s really sad, because if you read the literature, lung cancer is one of the items listed in association with this symptom. Shame on all of you.
hello i just turned 23 i was pregnant and thats when i really started realizing my finger nails are looking different i know what i have now clubbing nails…the doctor told me i’m gonna live another 80 years please i know he’s just saying it…he says it’ll go back to normal in two years but i know it’s not it’s only getting worser they did xray, PFT, blood gas test and blood test so far say nothing wrong…but now it’s looking worse only…my two thumb nails has a lump now and also along with one of my pinky…and my toes there all clubbing
…my toe at the end seems to be going higher then my toe nails now on the big toes…i dont’ know whats wrong…they won’t send me to a specialist i know till this day they don’t have a cure but in june 2010 i have having alot of chest pain when i started my job for 4 months then it went alway then i found out i was pregnant with my third son…and my nails really started to clubbing and i know it’s not getting any better please any idea on what test to do next…??…seems like my doc was just rushing me kause she wanted to go for lunch…and my chest pain hurted but now it doesn’t so i know the test ain’t gonna show it kause i’m not having the pain i had in 2010 but my mom said my great grandfather had something almost like mines but all his toes and fingers puss came out from to the point where he couldn’t walk….but all this i told my doc they don’t seem to really wanna help what do i do next…stressing me out more and more…
hi med cares,i am very happy in getting this resource about grade of clubbing.i searched it inn harrison but i could not find it.thank u for your invaluable work!!!!!!!!!
sorry!!!!, how disorder of lung and heart are associated with fingers and toes???