Clubbing of fingers or toes appears as the curled, spherical enlargement of the ends of the digits . The swelling of tissue distorts the normal placement of the skin and the nail plate, and causes the base of the nail to become spongy.
Disorders of the cardiopulmonary system and gastrointestinal tract can lead to clubbing – the acquired version. However, clubbing also may be inherited. Rarely, clubbing may be the result of acropachy, a thyroid disorder.
Newborn with bilateral club foot, also called congenital talipes equinovarus - Image Copyright: Alis Leonte / Shutterstock
Advanced clubbing - hypertrophic osteoarthropathy - involves a painful growth of connective tissue in long bones such as the tibia or radial bone. This inflammation occurs with a fever and joint pain or a large amount of fluid in the synovial area of a joint. Certain vascular conditions may additionally appear, along with bluish skin discoloration and sweating.
A rare condition called p achydermoperiostosis, characterized by thickening of facial skin, and an abnormal amount of sweat, may also include clubbing of the fingers. Pachydermoperiostosis may occur at a young age and progress slowly for about a decade. A person’s skin may become oily and thicken with this condition, which could be either inherited or acquired. The acquired form is associated with an existing cardiopulmonary or gastrointestinal condition.
Characteristics of clubbing
Often, there is no pain with clubbing. The condition affects both sides. The enlargement of the fingertips or toes occurs over time, and may not be noticed by the individual. In clubbing, the layer of cells under the nails becomes soft. The nails may seem to move around. The nail comes to a more acute angle to the cuticle. The finger’s extremity will enlarge and appear inflamed. Each involved nail bends downward, taking on the appearance of the round part of an inverted spoon.
Causes of clubbing
A specific cause of clubbing is not known. Generally, clubbing occurs with the onset of lung and heart conditions that reduce oxygen levels found in the blood.
- Congenital defects of the heart.
- Chronic pulmonary infections that are caused by bacterial or fungal organisms.
- Bacteria or fungi which infect the heart lining or the heart valves.
- Illnesses that occur with the swelling and scarring of the tissues of the lung.
More than three-quarters of clubbing conditions can be related to chronic lung issues. ardiovascular disorders may be involved in up to 15% of clubbing.A nd up to one-tenth of clubbing may be associated with constantly recurring liver and stomach disorders.
Clubbing may also be related to a number of other conditions, such as liver disease and celiac disease, dysentery, hyperthyroidism, and some forms of cancer, such as liver and stomach cancer.
The mechanism underlying clubbing is not definitively known. An increased flow of blood through the capillaries due to a neurocirculatory reflex could cause tissue hypertrophy and hyperplasia of the tissues. It is not clear whether the same mechanism contributes to inherited clubbing. A study of capillary blood flow in inherited clubbing showed no abnormally increased circulation. However, this could be due to the fact that in cases of inherited clubbing, the clubbing process is usually complete by the time studies are undertaken, whereas in acquired clubbing, the process is ongoing.
Acquired clubbing and osteoarthropathy may have different origins . E ach may occur independently . Clubbing and hypertrophic osteoarthropathy often occur simultaneously with an underlying condition. C lubbing may present before any other symptom of an underlying condition. It could, then, be an initial indicator of a tumor or other serious condition.
Treatments for clubbing
Only a few weeks may be needed for the onset of clubbing to occur. But after the underlying condition is treated, clubbing will resolve . There is no direct treatment for clubbing itself. Its cause can be treated, and it is usually reversible when the associated condition is treated successfully.
Reviewed by Catherine Shaffer, M.Sc.