A new manifestation of Cutaneous Pili MigransDear Editor: Cutaneous Pili Migrans is a rare skin disease first reported by Yaffee in 1957,it manifests as a creeping rash caused by hair shafts embedded in the superficial layers of the skin[1].To date, over 50 cases have been reported worldwide, and most cases have been reported in Asia[2].This report details a unique case involving a 40-year-old man who presented with Cutaneous Pili Migrans on the scrotum, characterized by a distinctive ring-like pattern.This atypical manifestation is rare, with limited literature addressing similar presentations. A 40-year-old man presented to the dermatology department after discovering a black ring of material beneath the epidermis of his scrotum.He reported no a history of trauma and did not experience any discomfort.There was no similar history reported among his family members. Physical examination revealed an annular, thick black hair shaft clearly visible beneath the epidermis of the scrotum,with slight inflammation at the center of the lesion(Figure 1).Dermoscopic examination showed a black annular hair shaft embedded below the epidermis,with any hair follicles and minimal inflammation in the surrounding skin（Figure 2).Based on the patient’s pertinent medical history and examination findings, we diagnosed the condition as Cutaneous Pili Migrans.Since it was asymptomatic, the patient requested conservative treatment. At the one-month follow-up, the lesion had resolved with no signs of recurrence. Our review of existing literature indicates that most reported cases of Cutaneous Pili Migrans present as a black line . In contrast, our case exhibited a black ring formation—a phenomenon not previously documented. While this is a rare finding, it would not be unusual for any hair bearing area with occlusion to develop this presentation, albeit rarely published. It is also plausible that the curly nature of the hair fibres in the scrotum could be inked with the ring presentation as opposed to curvilinear pattern in terminal hair shafts from the scalp or elsewhere, when exogenous or ingrown hairs that can take a different morphology. Additionally, typical rash locations in other cases include the soles of the feet, neck, legs, and abdomen, with no reports of lesions on the scrotum. This case enhances our understanding of Cutaneous Pili Migrans and may offer new insights for similar clinical presentations. Inflammation is rare in most cases of exogenous causes of Cutaneous Pili migrans and treatment involves removal of the hair shaft. In our case, the patient healed without any treatment.Inflammation is the body’s immune response that serves as a natural defense against damaged cells, pathogens, and harmful stimuli. Most inflammatory responses facilitating self-healing without specific treatment.This explains the spontaneous resolution observed in our case. Differential diagnosis of Cutaneous Pili Migrans is essential and includes Cutaneous Larval Migrans, interdigital pilonidal sinus, creeping eruption due to parasitic infections, and pseudofolliculitis barbae[3]. It is particularly important to distinguish Cutaneous Pili Migrans from Cutaneous Larval Migrans, as the two conditions share similarities[4]. Cutaneous Pili Migrans typically moves linearly in one direction, presenting as erythematous eruptions that are linear or wavy. In contrast, Cutaneous Larval Migrans can migrate in any direction, with lesions often appearing serpiginous or tortuous[5]. Additionally, lesions of Cutaneous Larval Migrans are characterized by intense itching and redness, lacking the distinct black line seen in Cutaneous Pili Migrans, which may be asymptomatic or painful[4].