Symptoms and progression
There are three forms of pilonidal cysts to be distinguished:
The bland (“mild”) form is a rather harmless form as it doesn’t show any signs of inflammation. The pilonidal cyst is only detectable – if at all – because of minor fistula orifices on the skin surface.
When the pilonidal cyst becomes inflamed, physicians speak of an acutely abscess-forming progression. The reason for the inflammation are the above mentioned ingrown hairs. Heavy sweating and tight, rough underwear that rubs on the skin also contribute to the inflammation.
In this case, the pilonidal cyst often gets visible through reddening and swelling. The area surrounding the cyst is quite sensitive then and strongly reacts on pressure. Sitting, walking and lying on the back cause severe pain. In some cases, purulent and bloody liquid is discharged out of the fistula orifice.
The chronic fistulous progression shows no acute signs of inflammation, but most people affected suffer from constant itching. Furthermore, the pilonidal cyst permanently discharges blood and pus which often shows in the respective stains in the underwear. Within a few days, the pilonidal cyst can become inflamed and swell considerably, which in turn is accompanied by severe pain.