Why does basal cell carcinoma cause a sore that will not heal?

Basal cell carcinoma begins in cells near the bottom of the outer skin layer. As the abnormal cells grow, they can weaken nearby tissue and prevent a small break in the skin from closing normally. The area may form a crust, shed the crust, and bleed or look raw again. It can resemble an irritated spot, a pimple, or a minor wound, especially on sun-exposed skin such as the face, ears, scalp, neck, and hands.

A persistent sore has many possible causes, including injury, infection, inflammation, or repeated rubbing. Its appearance alone cannot establish the cause. A clinician may examine it with magnification and may recommend a small skin sample when basal cell carcinoma needs to be confirmed.

Arrange a skin assessment for a sore that repeatedly crusts, bleeds, or reopens, particularly when it has not improved with ordinary wound care. Keep the area gently clean, avoid picking the crust, and protect it from friction and sunlight. Take note of when it began, whether it changes, and whether similar spots have appeared before.

Seek prompt medical attention if bleeding does not stop with steady gentle pressure, redness spreads, pain or swelling rapidly increases, or you develop fever. Otherwise, book a routine dermatology appointment for any sore that persists or keeps returning.

Could this sore need a biopsy, and what other causes are being considered? How should I protect and dress the area while it is being assessed? If treatment is needed, what type of procedure is appropriate for its location and size?