Skin cyst
Overview
Skin cysts are round lumps, often filled with fluid or pus. They're usually harmless and often do not need treatment. But see a GP if you have an unexplained lump.
Symptoms
Skin cysts: are round lumps just underneath the skinoften contain fluid or pussometimes have a small, dark spot in the middlegrow slowly and vary in size from smaller than a pea to several centimetres acrosscan get sore or red if they get infected – the redness may be harder to see on black or brown skin Skin cysts can form on most areas of the body, including the head, face, neck, chest and back. It's also possible to get them on the scrotum or inside the vagina.
Causes
Anyone can get a skin cyst and it's not always known what causes them. You may be more likely to get a skin cyst if: a family member also has cysts (particularly pilar cysts)you're an adult, particularly in middle ageyou're a womanyou haveacneyou have a rare condition, such as familial adenomatous polyposis syndrome Skin cysts are not cancerous and you cannot get them from someone who has one.
Treatment
Skin cysts do not need to be treated if they're not causing any problems. But treatment may be recommended if you have: an infected skin cyst – you may be givenantibioticsa large, painful cyst which interferes with everyday life – for example, a cyst on your head that catches when you brush your hair