Seborrheic keratoses can vary in size from very small to as large as an inch in diameter. They usually appear as waxy or wart-like growths, are round or oval shaped, and are often either flat or slightly raised with a scaly surface; SKs are often described as having a “stuck on” appearance. Seborrheic keratoses may itch or become irritated by clothing. They range in colour from light tan to brown or black, and frequently appear on the head, neck, chest, shoulders or back. You may develop a single growth, but multiple are more common. Though harmless, many patients decide to have them removed for cosmetic reasons, or if they begin to cause discomfort.