Pilonidal disease: Clinical sciences

Pilonidal disease refers to an acute or chronic infectious process within the natal cleft of the intergluteal or sacrococcygeal region. To review some embryology, the natal cleft or sulcus forms as a result of the anchoring of the deep layers of the skin to the anococcygeal raphe and the dorsum of the coccyx up to the tip of the sacrum.

Pilonidal disease is related to mechanical forces causing damage on the skin around the area, as well as disruption and breakage of hair follicles, and ultimately leading to the formation of natal cleft pores, where broken hairs and skin debris can accumulate. This is most commonly seen in young biologically male patients.

Pilonidal disease can present acutely as an infection such as folliculitis or cellulitis or the infectious process can further develop into an abscess. On the other hand, in chronic pilonidal disease, there are pilonidal cysts, sinuses, or tracts that contain inspissated debris such as hair and skin debris. That's right, we’re talking about a crack attack!

When a patient presents with a chief concern suggesting pilonidal disease, your first step is to obtain a focused history and physical examination, which will help determine if they have an acute or chronic disease.

Alright, some patients might report mild to moderate pain at the location of the intergluteal or sacrococcygeal region. The pain is usually associated with movement that causes the skin area to stretch. They might also report intermittent swelling along with purulent, mucoid, or bloody drainage from the location, as well as a fever, which means that an abscess might have formed.

Now, on a physical exam, you’ll typically find primary or midline natal cleft pores that may be acutely infected with signs of cellulitis like erythema and swelling; or folliculitis such as papules or pustules on an erythematous base. If your patient presents with this clinical picture, you can diagnose your patient with acute pilonidal disease.

Now that you have made the diagnosis, the next step is to assess if there is an associated abscess. If there is one, you’ll see a painful erythematous lump, and you'll feel fluctuance and might be able to express drainage. If these findings are present, you can diagnose your patient with a pilonidal infection with an abscess. The next step will be to consult the surgical team for incision, drainage, and curettage.

Okay, even though the abscess is drained, you’re still not done. In some cases, the abscess might remain after treatment, or it might reaccumulate in 48 to 72 hours. So, if you see findings consistent with reaccumulation, a remaining fluid collection, or a loculated abscess, it means that your patient has a refractory abscess or infection. If this is the case, consider repeat incision and drainage or adding an antibiotic to treatment.