Why would your thumb swell up and ache 2 days after taking out a splinter or metal burr?

Swelling and aching in the thumb two days after removing a splinter or metal burr can indicate an infection. Here are a few reasons why this might occur:

1. Incomplete Splinter or Burr Removal: If a small piece of the splinter or metal burr remains embedded in the skin, it can cause ongoing irritation and inflammation, leading to swelling and pain.

2. Infection: When the skin is punctured by a foreign object like a splinter or burr, it creates a pathway for bacteria to enter. If the wound becomes infected, it can cause swelling, redness, warmth, and pain in the affected area.

3. Abscess Formation: In some cases, an infection can lead to the formation of an abscess, which is a collection of pus and bacteria. An abscess can cause significant swelling, pain, and tenderness in the affected area.

4. Allergic Reaction: Some people may develop an allergic reaction to the material of the splinter or burr, such as metal or wood. This can cause swelling, itching, and redness in the affected area.

If your thumb is swollen, aching, or showing signs of infection, it's important to seek medical attention promptly. The healthcare provider can properly assess the situation, clean and dress the wound, and prescribe appropriate antibiotics or treatments if necessary. Self-treating an infected wound can increase the risk of complications.