The term “nail clubbing” refers to a change in the structure of fingernails or toenails during which they take on the appearance of an upside-down spoon and turn red and sponge-like. Symptoms such as shortness of breath or coughing may accompany it.
In most cases, lung cancer is the underlying cause, but heart disease, digestive disorders, and lung diseases are also possible causes. Clubbing can also be a genetic defect.
An examination of the fingers is typically enough to make the diagnosis, and a physician most often orders additional tests such as a chest computed tomography scan (CT scan) and more. It will depend on what the underlying cause of clubbing is.
Nail Clubbing Symptoms
The condition results from the growth of tissue in the distant part of the fingers (the terminal phalanges), enlarging the ends of the fingers and curling the nails downward.
Apart from becoming sponge-like and soft and having a reddish discoloration, the nails may change in angle and become curved. As the digits grow, they do so both laterally; side-to-side as well as longitudinally; longways.
The onset of clubbing occurs most often gradually, although some people experience it more rapidly. The symptom of secondary clubbing may disappear after successful treatment of the underlying cause.
Nail Clubbing Causes
There are numerous causes of nail clubbing, even though many physicians assume lung disorders are to blame. The following categories apply:
- Idiopathic: In this condition, there is no obvious reason for clubbing. It is not considered medically significant: it happens by itself.
- Inherited trait: There is often a 50:50 chance that one of your parents will carry the trait and you will as well.
- Secondary clubbing: In secondary clubbing, clubbing occurs due to a healthcare issue. Clubbing can cause conditions such as:
- Lung Cancer
- Other Cancer
- Lung Conditions
- Congenital Heart Disease
- Gastrointestinal Conditions
- Endocrine Problems
We still don’t understand the underlying processes behind clubbing. However, the precise mechanism is unknown, although scientists suspect platelet-derived growth factor and vascular endothelial growth factor are involved.
There are probably several mechanisms through which clubbing occurs, and no one is quite sure why. There are likely many different reasons why the appearance of clubbing occurs, with dilation of blood vessels leading to connective tissue formation in distant regions of the finger in many people.
Nail Clubbing Diagnosis
A physical exam will usually reveal clubbing, but it is likely to come as a result of another finding (e.g. lung disease or cancer).
A lump is often obvious, but when subtle, it may need to be confirmed by other findings and measurements. Some of these include:
- Lovibond angle: The angle formed by the nail base and the nail itself.
- The ratio between interphalangeal and distal depths.
- Schamroth sign: A gap (gap) between the fingers when both hands are held together with their tops touching each other.
Differential diagnosis: Rheumatoid conditions, such as reactive arthritis (Reiter syndrome), which can imitate the look of digital clubbing.
Clubbing Diagnosis Test
In the event you discuss clubbing with your doctor, the first thing that will go through their minds is to determine if it is a hereditary trait or if your doctor is aware of it. Thereafter, the doctor will conduct a careful physical exam, keeping in mind the causes associated with secondary clubbing.
If you have symptoms, you may be subjected to the following tests:
- An X-ray of your chest, as well as other studies to assess lung cancer and other lung and heart conditions, may be required
- Evaluation of your heart with an electrocardiogram (EKG) or an echocardiogram
- Tests for your pulmonary function and blood gases to evaluate your lung function.
- Tests of liver function and thyroid function in the blood
Nail Clubbing Treatment
Clubbing does not have a specific treatment, including surgery. Clubbing may be resolved for some people if they undergo treatment for the underlying cause. For instance, clubbing may resolve in people with heart valve defects after surgery.