Hypertrophic Osteoarthropathy

What is hypertrophic osteoarthropathy?

Hypertrophic osteoarthropathy (HOA) is a condition that causes clubbing of the fingers or toes. People with HOA will have:

• Enlarged ends of their fingers or toes.
• Nails that slope downward.

Underlying health problems may cause hypertrophic osteoarthropathy. But sometimes, people with HOA don’t have any other health conditions.

Hypertrophic osteoarthropathy may appear during childhood, in adolescence or not til later in life. HOA itself isn’t harmful, but any underlying conditions may need treatment.

What are the types of hypertrophic osteoarthropathy?

There are two types of hypertrophic osteoarthropathy:

• Primary hypertrophic osteoarthropathy (PHO): This type of HOA is genetic, meaning parents can pass it on to their children.
• Secondary hypertrophic osteoarthropathy (SHO): Chronic illnesses, such as heart and lung disease, cause this type of HOA. These illnesses are usually associated with lower oxygen levels in your blood.

Who might have hypertrophic osteoarthropathy?

People of every gender and race can have hypertrophic osteoarthropathy.

Primary hypertrophic osteoarthropathy usually appears during the first year after birth or during puberty. PHO is more common in:

• People who are Black.
• Men and people assigned male at birth.

Secondary hypertrophic osteoarthropathy usually appears between ages 55 and 75.

How common is hypertrophic osteoarthropathy?

Researchers don’t know exactly how many people have hypertrophic osteoarthropathy. But 95% to 97% of people with HOA have the secondary type.

What causes primary hypertrophic osteoarthropathy?

Genetic changes (mutations) present at birth cause primary hypertrophic osteoarthropathy. Either one or both parents may carry this gene mutation and pass it to their children.

What causes secondary hypertrophic osteoarthropathy?

The most common causes of secondary hypertrophic osteoarthropathy are lung diseases. When lung diseases cause this condition, the name of the condition is hypertrophic pulmonary osteoarthropathy (HPOA).

The most common lung disease that causes HPOA is lung cancer, especially non-small cell lung cancer. Other lung diseases that cause HPOA include:

• Benign fibrous tumors of the pleura.
• Chronic lung infections.
• Cystic fibrosis.
• Mesothelioma.
• Metastatic lung disease.
• Pulmonary arteriovenous malformation.
• Pulmonary tuberculosis.
• Sarcoidosis.

Other causes of secondary hypertrophic osteoarthropathy include:

• Conditions of the liver, bile, bile ducts and gallbladder (hepatobiliary conditions).
• Heart diseases.
• Gastrointestinal conditions.

Conditions of the liver, bile, bile ducts and gallbladder (hepatobiliary conditions) that cause SHO include:

• Biliary atresia.
• Cancer.
• Cirrhosis of the liver.
• Primary biliary cholangitis.
• Wilson’s disease.

Heart diseases that cause SHO include:

• Atrial myxoma, a non-cancerous tumor of the heart.
• Cyanotic heart disease.
• Infective endocarditis.

Gastrointestinal conditions that cause SHO include:

• Abuse of laxatives.
• Achalasia.
• Cancer.
• Familial adenomatous polyposis.
• Inflammatory bowel disease.

Other conditions that cause SHO include:

• Celiac disease.
• Dysentery, an infection of the intestines.
• Graves’ disease.
• Hyperthyroidism.
• Myelofibrosis.
• POEMS syndrome.
• Thymoma.

What are the symptoms of hypertrophic osteoarthropathy?

The main symptom of hypertrophic osteoarthropathy is clubbing of your fingers, toes or both. The clubbing usually affects both sides of the body equally. You may see:

• Bulging and rounded tips of your fingers, toes or both.
• Disappearance of the creases over the knuckles closest to your fingertips.
• Nails that curve downward and look like they’re floating.
• Shiny, thin skin at the base of your nails.
• Softening of your nails.
• Warmth or redness on the tips of your fingers, toes or both.

Other HOA symptoms may include:

• Excessive growth of glands (glandular hypertrophy). This can result in acne, hyperhidrosis, upper eyelid ptosis (drooping eyelid) and seborrheic dermatitis.
• Inflammation in the membranes covering your bones (periostosis). This may cause tenderness of the ankles, wrists or knees.
• Swelling of the soft tissue in your legs (non-pitting edema).
• Thickening of the bones in your ankles and wrists.
• Thickening of the skin (pachydermia). Skin on the face and scalp can become coarse, with deep grooves.

What are the symptoms of secondary hypertrophic osteoarthropathy?

In addition to the same general HOA symptoms, secondary hypertrophic osteoarthropathy symptoms may include swollen joints (joint effusions). Extra fluid builds up in the tissues in and around your joints. Joint effusions can cause:

• Pain.
• Redness.
• Stiffness.
• Swelling.

Joint effusion related to SHO tends to occur in the knees and wrists.

How is hypertrophic osteoarthropathy diagnosed?

Your healthcare provider will first look for clubbing on your fingers or toes. They will also do a physical exam to look for:

• Coarse facial features.
• Swelling in your legs.
• Tenderness in your ankles, knees or wrists.
• Thickening of your ankle and wrist bones.

If your provider suspects hypertrophic osteoarthropathy, they will use tests such as:

• Lovibond’s profile sign: When you look at your finger from the side, you usually see a wide “V” shape where the hard part of your nail (nail plate) meets the fold of skin at the bottom of your nail (proximal nail fold). If you have HOA, your nail points downward, and the angle increases between your nail plate and proximal nail fold. The angle will be less than or equal to 160 degrees with a normal nail, while it will be more than or equal to 180 degrees with a clubbed nail.
• Phalangeal depth ratio: You have three bones (phalanges) in each finger. The bone that includes your nail (distal phalange) is usually shorter than the phalange next to it (middle phalange). If you have HOA, your middle phalange will be shorter than your distal phalange.
• Schamroth’s sign: When you put your fingers together with the tops of your nails facing each other, look for the place between your nail beds and cuticles to form a diamond-shaped window. If you don’t have a window, you may have HOA.

How is secondary hypertrophic osteoarthropathy diagnosed?

If your healthcare provider suspects that hypertrophic osteoarthropathy has an underlying medical cause, they may suggest tests such as:

• Angiography.
• Arterial blood gas.
• Blood tests.
• Bone scan.
• Chest X-ray.
• CT (computed tomography) scan or ultrasound.
• Echocardiogram or electrocardiogram (EKG).
• Magnetic resonance imaging (MRI).
• Pulmonary function testing.

These tests can help your provider to figure out the cause of the HOA. If an imaging test shows any growths, your provider may also suggest a biopsy. This can help them determine the cause of the growth.

How is hypertrophic osteoarthropathy treated?

You may not need treatment for primary hypertrophic osteoarthropathy unless you experience pain or symptoms worsen. Treatments may include medications such as:

• Non-steroidal anti-inflammatory drugs (NSAIDs).
• COX-2 inhibitors.
• Bisphosphonates.
• Octreotide.

How is secondary hypertrophic osteoarthropathy treated?

Treatments for secondary hypertrophic osteoarthropathy also include management of the underlying cause. Treatments may include:

• Antimicrobial therapy, to treat pulmonary tuberculosis.
• Chemotherapy, to treat lung cancer.
• Liver grafts or liver transplantation, to treat liver disease.
• Lung transplant surgery, to treat cystic fibrosis.
• Radiofrequency ablation, to treat lung tumors.
• Surgery, to treat heart problems or lung cancer.

If your provider can’t treat the underlying cause of SHO, they may suggest treatment of symptoms with medications.

How soon after treatment will I see results?

Results will depend on the type of hypertrophic osteoarthropathy you have, the severity of your condition and the treatment you use. Once your provider treats your underlying condition, the clubbing may go away quickly.

How can I reduce my risk of primary hypertrophic osteoarthropathy?

You can’t reduce your risk of primary hypertrophic osteoarthropathy because it’s an inherited form of HOA.

How can I reduce my risk of secondary hypertrophic osteoarthropathy?

You can reduce your risk of SHO by leading a healthy lifestyle, especially if you’re at risk for heart or lung problems. Steps you can take include:

• Achieve and maintain a healthy weight.
• Eat a heart-healthy diet.
• Exercise.
• Limit your intake of alcohol and recreational drugs.
• Quit smoking.
• Reduce stress.

What can I expect if I have primary hypertrophic osteoarthropathy?

Primary hypertrophic osteoarthropathy may stop getting worse on its own. It sometimes goes away completely, especially after adolescence.

What can I expect if I have secondary hypertrophic osteoarthropathy?

Secondary hypertrophic osteoarthropathy can go away completely after treatment for the underlying cause. But if your provider can’t successfully treat the underlying cause, you’ll continue to have SHO. For instance, providers may be unsuccessful in treating SHO related to aggressive cancer.

What is the outlook if I have hypertrophic osteoarthropathy?

If you have hypertrophic osteoarthropathy for a long time, you may experience:

• Loss of range of motion.
• Osteoarthritis.
• Pain.

But you can manage many symptoms with proper treatments.

How do I take care of myself with hypertrophic osteoarthropathy?

You can take care of yourself with HOA by continuing with any treatments that help to control your symptoms.

When should I see my healthcare provider?

See your provider if you notice any symptoms of clubbing coming back after treatment. This may indicate a return of the underlying condition.

Also, see your provider with any concerns about side effects from your treatments or if you don’t notice any results after some time. They’ll be able to suggest other treatments that may help.

A note from Cleveland Clinic

Hypertrophic osteoarthropathy (HOA) is a condition that leads to clubbing of the fingers or toes. Genetics cause primary hypertrophic osteoarthropathy (PHO), while underlying health conditions, especially lung and heart conditions, cause secondary hypertrophic osteoarthropathy (SHO). Besides clubbing, other symptoms may include tender ankles, knees or wrists, swollen legs and thickened facial skin.

Providers diagnose HOA with a physical exam and specific tests. Treatments for PHO include medications to manage symptoms. But treatments for SHO focus on treating the underlying condition. PHO may stop progressing or resolve on its own. The outlook for SHO depends on whether treatment for the underlying condition is successful.