Differential Diagnosis for a Wart on the Finger

• Single most likely diagnosis
  • Common wart (Verruca vulgaris): This is the most common type of wart and frequently appears on the fingers. It is caused by the human papillomavirus (HPV) and is characterized by a rough, hard, or flat growth.
• Other Likely diagnoses
  • Plantar wart (Verruca plantaris): Although more common on the soles of the feet, plantar warts can occasionally appear on the fingers, especially if there has been direct contact with an infected area.
  • Flat wart (Verruca plana): These are smaller and smoother than common warts and can appear on the fingers, often in large numbers.
  • Molluscum contagiosum: A viral infection that causes small, pearly, or flesh-colored bumps. It can appear anywhere on the skin, including the fingers.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Squamous cell carcinoma: A type of skin cancer that can present as a wart-like lesion. It's crucial to differentiate it from a benign wart, especially in individuals with risk factors such as prolonged sun exposure or immunosuppression.
  • Keratoacanthoma: A low-grade, or sometimes benign, tumor that can resemble a wart but has the potential to grow rapidly and can be mistaken for squamous cell carcinoma.
• Rare diagnoses
  • Verrucous carcinoma: A rare, low-grade malignancy that can present similarly to a wart but is more aggressive and can invade deeper tissues.
  • Epidermoid cyst: While not typically resembling a wart, an epidermoid cyst can sometimes present as a firm, rough lesion that might be confused with a wart, especially if it becomes inflamed or infected.
  • Dermatofibroma: A benign skin growth that can appear as a firm, rough lesion but is usually distinguished from a wart by its characteristic dimpling when pressed from the sides.