What might cause a rash that looks like fingernail scratches then fades moves around every few minutes?

Possible causes of a rash that looks like fingernail scratches and fades/moves around every few minutes:

- Dermatographia (skin writing): This is a common skin condition that causes the skin to develop raised, red marks in response to light scratching or pressure. The marks usually appear within minutes of being scratched and can last for up to 30 minutes. Dermatographia is thought to be caused by a release of histamine from the skin's mast cells in response to scratching or pressure.

- Allergic reaction: Some people may develop a rash that looks like fingernail scratches in response to an allergen, such as food, pollen, or dust mites. The rash may appear within minutes of exposure to the allergen and can last for several days.

- Insect bites or stings: Insect bites or stings can cause a rash that looks like fingernail scratches. The rash may appear within minutes of being bitten or stung and can last for several days.

- Infections: Some infections, such as chickenpox and shingles, can cause a rash that looks like fingernail scratches. The rash may appear within a few days of exposure to the infection and can last for up to 2 weeks.

- Other medical conditions: A rash that looks like fingernail scratches can also be a symptom of other medical conditions, such as lupus, thyroid problems, and cancer. If you are experiencing a rash that is accompanied by other symptoms, such as fever, joint pain, or fatigue, it is important to see a doctor to determine the cause.

If you are experiencing a rash that looks like fingernail scratches and are not sure what is causing it, it is important to see a doctor to get a proper diagnosis and treatment.