What should you know about reactive keratoacanthoma?

Keratoacanthoma often appears as a firm, dome-shaped skin lump with a central keratin plug. It may develop over a short period on sun-exposed skin such as the face, ears, forearms, or backs of the hands. The word reactive can suggest a growth that followed inflammation, injury, or irritation, but appearance alone cannot reliably separate it from squamous cell carcinoma or another lesion.

Because the distinction affects treatment, a dermatologist may examine the lesion with magnification and recommend a biopsy or removal. Do not squeeze, cut, burn, or cover it with unprescribed wart treatment. Mention a history of [Sun-Damaged Skin](/conditions/photoaging/) and any change in bleeding, tenderness, crusting, or size.

Book a prompt dermatology appointment and take a clear photograph to document change. Protect the area from sun and avoid friction from shaving, clothing, or adhesive dressings. Keep the surface clean if it has crusted or opened, and ask the clinic how to dress it rather than applying household chemicals.

Treatment depends on the examination and tissue diagnosis. Options may include [Surgical Excision](/treatments/surgical-dermatology/excisional-surgery/) or [Curettage And Cautery](/treatments/surgical-dermatology/curettage-and-cautery/). Your clinician will explain whether margins, follow-up checks, or additional treatment are needed.

Contact a dermatologist promptly if the lump is enlarging, bleeding, painful, repeatedly crusting, or interfering with an eye, nose, ear, or mouth. Seek urgent care for uncontrolled bleeding, spreading redness with fever, or severe swelling. A lesion that changes quickly should not be watched at home simply because it is called reactive.

Does this need a biopsy or complete removal? How will the tissue be checked? Which procedure suits its location and depth? What wound care should I use, and when should the site be reviewed? How can I protect nearby sun-damaged skin?