Pilonidal cyst

Background

1. Sinus is formed by penetration of skin by ingrowing hair
   1. Leads to foreign body granuloma reaction, sinus perpetuated by repeated bouts of infxn
2. Carcinoma is rare complication of chronic, recurring pilonidal sinus disease

Diagnosis

1. May present as a painless cyst, acute abscess, or recurring cysts w/ draining sinuses
2. Occurs in midline in the upper part of the natal cleft
   1. Does not communicate with the anorectum
   2. Because of proximity to anus can be confused for a perianal abscess

DDX

1. Anal fistula
2. Syphilitic and tuberculous granulomas
3. Simple furuncles
4. Fungal infection
5. Sacral osteomyelitis

Treatment

1. I&D
2. Abx only needed if cellulitis is present
3. Refer to surgeon for recurrent disease

Source

Tintinalli