Clinical Features of Pilonidal Cyst
Pilonidal cysts present as inflammatory nodular lesions in the sacrococcygeal region (natal cleft of the buttocks) in young adults, predominantly men, characterized by midline pits with hair entrapment, recurrent pain, and purulent drainage.
Demographics and Location
The disease shows a strong male predominance with a 3-4:1 male-to-female ratio and typically manifests during the late second decade of life 1. While the sacrococcygeal region is the classic location [@1,2@], rare presentations can occur on the scalp, penis, interdigital regions, and cervical areas [@7,9,10@].
Clinical Presentation Spectrum
Early/Asymptomatic Phase
- Solitary, firm, pink nodular lesions near the gluteal cleft 1
- Visible midline pits in the sacrococcyx area due to hair entrapment 2
- Initially painless and may present to dermatology clinics 1
Acute/Complicated Phase
- Abscess formation with warmth, tenderness, and purulent drainage 3
- Pain and local infection with redness 4
- Intermittent drainage episodes 2
- Moderate debility in some patients 5
Dermoscopic Features (When Examined)
Recent dermoscopic characterization reveals distinctive patterns 1:
- Pink homogenous background (most consistent finding)
- Central ulceration with yellow or red structureless areas
- Peripherally arranged vessels: dotted, glomerular, and hairpin patterns (distinguishing from other cysts which show linear vessels)
- White reticular lines at periphery
Pathophysiology
The condition represents a chronic inflammatory disease of follicular occlusion characterized by [@1,2@]:
- Perifollicular inflammatory nodules
- Interconnected draining tunnels/sinus tracts
- Hair penetration beneath the skin
- Granuloma formation around foreign bodies (hairs) 6
Important Clinical Pitfalls
Women are frequently misdiagnosed and undertreated because the disease is less common in females, leading to delayed appropriate care 3. The disease can mimic fistula-in-ano with perianal drainage 2, requiring careful examination to identify the characteristic midline pits. The impact on quality of life, work productivity, and daily function should not be underestimated [@6,11@].
Associated Conditions
When pilonidal disease is identified, consider screening for hidradenitis suppurativa, as both are chronic inflammatory diseases of follicular occlusion with similar pathophysiology [@1,2@]. Patients with HS have 4.97 to 5.61 times higher odds of having pilonidal disease [@1,2@].