Finger pulp infection

Published by Bupa's Health Information Team, November 2010.

This factsheet is for people who have a finger pulp infection, or who would like information about it.

A finger pulp infection most commonly affects the fleshy area at the tip of the finger known as the finger pulp. Often the infection starts from a cut or a splinter.

About finger pulp infection

A finger pulp infection is an infection in the fleshy part of your fingertip (on the palm side). It may also be referred to as staphylococcal whitlow. Infections are most common in your thumb and index finger.

The infection in your fingertip can often start from an opening in your skin, for example if you get a cut or splinter. This happens to about half of people with a finger pulp infection.

Symptoms of finger pulp infection

Your symptoms will be concentrated around your fingertip and may include:

• a tightness or pricking sensation
  
• redness
  
• swelling
  
• feeling hot and tender to touch
  
• a pus-filled blister (abscess)
  
• throbbing pain

Complications of finger pulp infection

The main complication of a finger pulp infection is osteomyelitis. This is when the infection spreads to the bone underneath your fingertip. If left untreated, it starts to destroy the bone and can eventually cause an abscess in the bone.

Other complications are listed below.

• Skin necrosis. This is when the tissue in and around the infected area starts to die. This happens because there isn't enough blood getting through to the tissue. The skin on your fingertip will appear much darker and may turn a purple or black colour. This can lead to scarring of the fingertip.
  
• Septic arthritis. This happens when the infection spreads to your finger joint. This can cause your finger joint to become painful and swollen.
  
• Tenosynovitis. This is when the infection spreads to the sheath that surrounds the tendons in your finger. It causes pain, swelling and tenderness around the affected area. It's the most serious complication of a finger pulp infection because the infection can keep on spreading through the sheath up the hand and arm.
  
• Compartment syndrome. This happens when swelling compresses the nerves and blood vessels within your fingertip. This can lead to poor blood flow and nerve and muscle damage.

Causes of finger pulp infection

The most common cause of a finger pulp infection is Staphylococcus aureus. This is a bacterium that usually lives on your skin without causing you any harm. Occasionally it gets inside your body through breaks in your skin, for example a cut, and causes an infection.

Meticillin-resistant Staphylococcus aureus (MRSA) can also cause a finger pulp infection, although this is less common. MRSA is resistant to several types of antibiotics, making it much more difficult to treat.

Other types of bacteria have been found to cause finger pulp infection, although this is quite rare and usually only happens to people who have a weakened immune system.

A finger pulp infection can also result from a paronychia. A paronychia is an infection in the skin at the edge of your fingernail. The infection can spread to the fleshy part of your fingertip and cause an infection in your finger pulp.

Diagnosis of finger pulp infection

Your doctor will ask about your symptoms and examine you. He or she may also ask you about your medical history.

Your doctor may need to take a swab of the infected area to test it to see what has caused the infection. This is usually only done if the initial treatment hasn't worked.

Treatment of finger pulp infection

Self-help

Your GP will advise you to keep your finger elevated as much as possible. He or she may also recommend that you soak your finger in warm water three or four times a day.

Medicines

To treat the infection, your GP will prescribe you antibiotic tablets called flucloxacillin that you will need to take for seven days. If you're allergic to penicillin you won't be able to take flucloxacillin. Your doctor may prescribe erythromycin or clarithromycin instead. Always ask your doctor for advice and read the patient information leaflet that comes with your medicine. It's important that you take the complete course of antibiotics.

If you need pain relief, you can take over-the-counter painkillers such as paracetamol or ibuprofen. Always read the patient information that comes with your medicine and if you have any questions, ask your pharmacist for advice.

Surgery

If you have an abscess, you will need to have it drained. The procedure is called incision and drainage. Your GP may do this or you may be referred to a hospital for treatment.

The procedure involves making a small cut over the most inflamed area of your fingertip so that the pus and fluid inside can be removed. The wound is then packed with gauze to keep it open and allow the fluid to continue draining out. Your finger will be covered with a loose dressing and finger splint. You may need to wear a sling to keep your finger elevated above the level of your heart.

You will be given a course of antibiotics to complete and a follow-up appointment to have the dressing removed at the hospital or your GP's surgery.

If your symptoms continue to get worse or you don't respond to these treatments, go back to see your GP. He or she will refer you to a hand surgeon for further investigation.

Prevention of finger pulp infection

Most finger pulp infections are caused by a break or cut in the skin. There are simple steps you can take to reduce your risk of infection.

• If you have damaged skin or a cut, keep it covered with a waterproof dressing. Always wash your hands before and after changing the dressing.
  
• Wash your hands with soap and hot water after going to the toilet and before and after you eat.

For answers to frequently asked questions on this topic, see Common questions.

For sources and links to further information, see Resources.