A pink, dome-shaped bump with a hard plug in the center can look alarming, particularly when it seems to grow quickly over a matter of weeks. One possibility a doctor may consider is a keratoacanthoma, a skin growth that often develops rapidly. However, these lesions can closely resemble squamous cell carcinoma, a form of skin cancer, making professional evaluation important.

Keratoacanthomas commonly appear as firm, raised, round growths on areas exposed to the sun, including the forearms. Their central keratin plug can give them a distinctive crater-like or volcano-shaped appearance. Although they are more frequently seen in older adults and people with significant sun exposure, appearance alone cannot determine whether a growth is harmless or potentially cancerous.

Until the bump has been examined, it is best to leave it alone. Avoid squeezing, cutting, picking, freezing, burning, or applying wart-removal products. If clothing repeatedly rubs against the area, a clean, nonstick dressing can provide gentle protection. Taking occasional photographs with a ruler beside the lesion may also help document changes in its size or appearance.

A dermatologist may recommend a biopsy or removal to determine exactly what the growth is. Because keratoacanthomas and squamous cell carcinomas can be difficult to distinguish based only on appearance, tissue examination may be necessary. A rapidly changing, bleeding, painful, or otherwise unusual skin growth deserves timely medical attention rather than experimentation with home remedies.

The most important message is not to panic, but also not to ignore a rapidly changing bump. Many skin growths have benign explanations, yet some require treatment, and early evaluation can provide clarity. Protect the area, avoid manipulating it, and arrange an appointment with a healthcare professional as soon as reasonably possible.