Pilonidal disease

The diagnosis of pilonidal disease is clinical, and diagnostic tests are not required.

History and physical findings

Pilonidal disease has a variable clinical presentation. Some patients are unaware of the disease and may be identified on a routine physical examination as one or more pits in the midline of the natal cleft.

Other patients may present with an acute exacerbation characterised by sudden onset of mild-to-severe pain in the natal cleft. The patient may also describe swelling and/or purulent or bloody discharge from the area. The presence of a fever or malaise are indicative of an undrained abscess. On physical examination, there is often cellulitis in the natal cleft associated with a tender, fluctuant mass commonly located just lateral to the midline at the superior aspect of the natal cleft. If the abscess has spontaneously ruptured, there may be purulent and/or bloody discharge associated with the abscess cavity.

[Figure caption and citation for the preceding image starts]: Acute sacrococcygeal pilonidal abscessWalker H, et al. BMJ 2023; 382: e071511; used with permission [Citation ends].

Patients with chronic pilonidal disease often report a prior history of a pilonidal abscess that was either drained by a provider or spontaneously. These patients endorse persistent intermittent or constant drainage that may be associated with pain or discomfort. On physical examination, one or more sinus openings can be visualised with mucoid, purulent, and/or bloody fluid. The deep skin of the natal cleft is often macerated and hair may be visualised protruding from the sinus opening.