Why does keratoacanthoma cause a sore that will not heal?

Keratoacanthoma is a keratin-filled skin growth that often develops from a hair follicle or nearby surface cells. As it enlarges, the middle may become plugged with hard keratin and the surrounding skin may become raised, firm, or inflamed. The surface can crack, crust, or remain open, so ordinary repair is interrupted by the ongoing growth. It may look like a crater or a wound that repeatedly crusts after seeming to improve.

A non-healing sore has several possible causes, including irritation, infection, trauma, and other skin growths. Appearance alone cannot confirm keratoacanthoma. A clinician may examine the area closely and recommend a tissue sample because keratoacanthoma can resemble a form of skin cancer.

Arrange a timely skin examination, especially if the spot is enlarging, firm, bleeding, tender, or repeatedly reopening. Until it is assessed, wash gently, pat dry, and cover it with a clean non-stick dressing if clothing rubs against it. Do not squeeze, scrape, or attempt to remove the central plug. Protect the area from sun exposure and note changes in its size, crust, bleeding, and discomfort.

A dermatologist can decide whether biopsy or removal is appropriate. Treatment is chosen after examination and may address the entire growth rather than only its surface crust.

Seek prompt medical assessment for a sore that continues to enlarge, bleeds with little contact, becomes increasingly painful, develops spreading redness or drainage, or does not close. Seek urgent help for heavy bleeding that does not stop with steady gentle pressure, or for fever with rapidly worsening redness and swelling.

Ask whether the growth needs a biopsy, which features make keratoacanthoma more or less likely, how quickly it should be treated, and how to dress the area while waiting. You can also ask what changes should trigger earlier review.