Making room for something new often means letting go of the old first. The same is true for our skin.
A cyst on the shoulder can sit under the skin for years, slowly growing as it fills with old, trapped keratin.
Around it, small blackheads often appear, because the pores in that area are large and easily blocked by oil and sweat.
When the cyst becomes irritated, the skin turns red and swollen, and the lump can feel firm and sore to the touch.
Once it is opened, the material inside often comes out as a long, thick, yellowish strand, which is the built-up keratin.
