Differential Diagnosis for Toenail Discoloration and Pain
- Single most likely diagnosis
- Subungual hematoma: This condition occurs when blood accumulates under the toenail, often due to trauma, and can cause discoloration (black or green) and pain. The tenderness to the touch, especially with pressure at certain angles, is consistent with this diagnosis.
- Other Likely diagnoses
- Onychomycosis (fungal infection of the toenail): This infection can cause discoloration of the toenail and pain, especially if the infection is severe or has led to the formation of a subungual hematoma.
- Paronychia: An infection of the skin around the toenail can cause pain, tenderness, and discoloration, and may be mistaken for an ingrown toenail.
- Ingrown toenail (despite the patient's statement): It's possible that the patient has a small or partial ingrown toenail that is not visible, or that the pain is referred from another area.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Osteomyelitis (bone infection): Although less likely, osteomyelitis can cause pain and tenderness in the toe, and can be life-threatening if not treated promptly.
- Cellulitis or abscess: A bacterial infection of the skin and soft tissues can cause pain, tenderness, and discoloration, and can lead to serious complications if not treated.
- Melanoma (subungual melanoma): A rare but potentially deadly type of skin cancer that can cause discoloration of the toenail.
- Rare diagnoses
- Subungual glomus tumor: A rare, benign tumor that can cause pain and tenderness under the toenail.
- Subungual keratoacanthoma: A rare, benign tumor that can cause a painful, tender lesion under the toenail.
- Toenail trauma or fracture: A traumatic injury to the toenail or toe can cause pain, tenderness, and discoloration.