Single most likely diagnosis:
- Excoriation or Abrasion: This is the most likely diagnosis due to the direct trauma from scratching, which can cause superficial skin layers to be removed, leading to bleeding.
Other Likely diagnoses:
- Laceration: If the scratching was deep or with a sharp object, it could result in a laceration, which is a tear in the skin.
- Hematoma: Especially if the scratching caused damage to blood vessels under the skin, leading to blood accumulation and swelling.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Infection: Any break in the skin can lead to infection, especially in areas that are difficult to keep clean, like the sacral area. Infections can escalate to severe conditions like sepsis if not treated promptly.
- Anal or Rectal Trauma: Depending on the exact location and depth of the wound, there could be injury to the anal or rectal mucosa, which requires immediate medical attention to prevent infection and further complications.
Rare diagnoses:
- Pilonidal Sinus or Cyst: While rare, scratching could potentially irritate or rupture a pre-existing pilonidal sinus or cyst in the sacral area, leading to infection or abscess formation.
- Pressure Ulcer (Decubitus Ulcer): Though less likely without a history of prolonged pressure on the area, any wound in the sacral region could potentially develop into a pressure ulcer, especially in individuals with mobility issues.