Most of the cysts or cysts like lesions appearing externally on skin are harmless. If there is any pain or redness, it may be due to infection of skin glands like sebaceous glands or hair follicles. Sometimes there is pus formation and pus can be seen extruding, when pressure is applied. Cyst like swelling can form following minor trauma, due to foreign body getting embedded in skin around which a pus filled swelling may occur.
Lipomas are formed by accumulation of lipid cells and can be felt as movable swellings under skin. They are usually harmless and need not be removed unless other complications like inflammation or pressure on nerves etc., are present. Other harmless conditions like cherry angiomas (due to abnormal small blood vessels of skin), epidermoid cysts (sebaceous gland cysts) may appear as cystic swellings on skin. Only if the cyst is growing in size or appear fixed to the underlying tissues or bone, then a possibility of tumor (either benign or malignant cancer) has to be ruled out. You need not be scared to go to a physician as in most of the cases cysts does not even require any treatment and in case of infection or pressure symptoms or cosmetically required, simple excision of cyst is enough as treatment.
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