Epidermal cyst (atheroma)

An epi­der­mal cyst is a benign cavi­ty in the skin fil­led with kera­tin mate­ri­al. It feels like a firm, ela­s­tic nodu­le beneath the skin and grows slow­ly. It is com­mon­ly refer­red to as a sebace­ous cyst.

Cau­ses

The cyst deve­lo­ps when the duct of a hair fol­lic­le beco­mes blo­cked and shed hor­ny cells accu­mu­la­te insi­de. It can appear spon­ta­neous­ly or after an inju­ry. A fami­li­al ten­den­cy is pos­si­ble; its deve­lo­p­ment has not­hing to do with hygiene.

Sym­ptoms

Typi­cal is a mobi­le, skin-colou­red nodu­le from a few mil­li­me­t­res to seve­ral cen­ti­me­t­res in size, often with a tiny cen­tral pore. Cysts occur pre­fe­ren­ti­al­ly on the head, neck, back and face. When infla­med, the nodu­le beco­mes red, pain­ful and may dischar­ge foul-smel­ling contents.

Tre­at­ment

Tre­at­ment is only neces­sa­ry if the cyst is bother­so­me, grows or repea­ted­ly beco­mes infla­med. The stan­dard is com­ple­te sur­gi­cal rem­oval inclu­ding the cyst wall, as other­wi­se it recurs. An acu­te­ly infla­med cyst is first drai­ned and only remo­ved once the inflamm­a­ti­on has settled.