What should you know about keratoacanthoma dermnet?

Keratoacanthoma often appears as a round, raised lump on sun-exposed skin, such as the face, ears, backs of the hands, forearms or lower legs. It may have a hard, keratin-filled centre that looks like a plug or crust. Growth can be noticeably quick, but appearance alone cannot distinguish this lesion from an invasive squamous cell carcinoma. A clinician may therefore use the same cautious approach for both. Sun exposure and older, sun-damaged skin are common clinical contexts, although a diagnosis cannot be made from a photograph or from speed of growth alone.

The name describes a pattern of growth, not a diagnosis that can be confirmed at home. Examination and tissue assessment may be needed to identify the lesion and check its edges and depth. Do not squeeze, shave or repeatedly pick at the centre, because this can cause bleeding, infection or make the lesion harder to assess.

Arrange a dermatology appointment promptly for any new lump that enlarges quickly, develops a central crust or plug, or does not settle. Before the visit, note when you first noticed it, how it has changed, and whether it has bled, become tender or formed an open sore. A clinician may photograph it, examine nearby skin and recommend a biopsy or removal so the tissue can be checked. Common procedural options include curettage and cautery or surgical excision, selected according to the lesion’s location, size and clinical features.

Protect the area from further sun exposure with clothing and shade, and use broad-spectrum sunscreen on exposed skin as directed. Sun-damaged skin can develop several different types of growth, so prevention supports skin health but does not replace assessment of an existing lump.

Seek prompt medical review if the lump is growing quickly, bleeds with little contact, becomes increasingly painful, develops pus or spreading redness, or forms a persistent ulcer. Contact urgent care sooner for heavy bleeding that does not stop with firm pressure, rapidly spreading redness with fever, or severe pain. These warning signs do not identify the cause by themselves; they indicate that the skin needs timely examination and treatment.

Ask whether the growth needs a biopsy or complete removal, what the procedure will involve, how the wound will be cared for, and when the tissue result should be discussed. You can also ask whether nearby sun-damaged areas need examination and how to reduce further ultraviolet exposure.