Raised patches that look like moles

They appear after the age of forty and increase with time: small raised plaques, brown or almost black, with a dull, slightly greasy surface. They look stuck onto the skin rather than part of it, and indeed the typical impression people describe is "it looks as if it could be picked off with a fingernail."

They are benign lesions, and this should be said at once because the worry that brings them to the clinic is almost always the same: the fear that they are moles that are changing. They are not moles, and they do not derive from sun in the same way as actinic keratoses: they are a benign growth of keratinocytes, linked mainly to age and to family predisposition — those who have them often have many, and often had a parent who did too.

The delicate point is different: a pigmented seborrhoeic keratosis and a melanocytic lesion can look alike to the naked eye. Dermatoscopy distinguishes them reliably, because they show different structures. The correct answer to "is it just a keratosis?" is therefore not reassurance at a distance, but looking at it — and it is usually a quick assessment.

Once established that this is what they are, they require no treatment. They are removed for practical or cosmetic reasons: when they catch on clothing or bra straps, when they become repeatedly irritated, or when they sit somewhere visible that bothers the person. Removal is a choice, not a necessity — and it is a distinction worth hearing clearly.