Dermoid sinus disease is characterized by the presence of ectodermal elements—such as hair, sebaceous material, and skin appendages—within a cystic or sinus tract.1,2 While dermoid sinuses are more commonly described in certain well-known locations (e.g., sacrococcygeal area, scalp, or midline sites due to congenital fusion lines), they can occasionally present in atypical regions3-6 Infraclavicular dermoid sinus is extremely rare and can be misdiagnosed as a chronic abscess, infected sebaceous cyst, hidradenitis suppurativa, or cutaneous tuberculosis sinus.5,7- This report details a 7-year-old child with a chronic, discharging sinus in the right infraclavicular region containing hair, ultimately diagnosed as an atypical dermoid sinus.

A 7-year-old child presented with a one-year history of intermittent purulent discharge from the right infraclavicular area. The caregiver reported occasional swelling, localized pain, and the presence of hair strands protruding from the sinus opening. The child had no significant past medical or surgical history. On inspection, a small sinus opening (~5 mm) located ~3 cm below the right clavicle. (Figure 1) Hair shafts were visible at the orifice. Mild erythema surrounded the opening. A palpable tract reaching toward the collarbone and pain upon deep probing were seen. No fluctuance was noted in the adjacent subcutaneous tissue. The patient’s vital sign were normal for the child’s age: Temperature 37.2°C, Heart rate 90 bpm, Blood pressure 100/60 mmHg, Respiratory rate 18 breaths/min.

The Ultrasonography revealed a hypoechoic tract (~4 cm in length) in the subcutaneous tissue extending from just below the clavicle to the skin surface, with suspicion of embedded hair. The finding was further confirmed with MRI dictating a sinus tract confined to the subcutaneous plane with no deeper fascial or muscular involvement. Furthermore, the laboratory investigations showed normal blood chemistry profiles, mild leukocytosis (WBC 11,000 cells/µL),  and mildly elevated ESR and CRP (Table 1).

The surgery was performed under general anesthesia, an elliptical incision (Figure ) was made around the sinus opening. The sinus tract was carefully dissected along its entire length up to the inferior border of the right clavicle. All tracts and any offshoots were excised. During surgery it was observed that the tract contained hair shafts, keratinous debris, and evidence of chronic inflammation. No extension beyond the subcutaneous plane was observed. After thorough irrigation with antiseptic solution, the wound was closed primarily using interrupted non-absorbable sutures. (Figure ) A small suction drain was placed if any dead space was present.

The excised mass was then sent for histopathological analysis that revealed hair shafts, keratinous debris, and granulation tissue with chronic inflammatory changes, confirming a dermoid sinus. No evidence of malignancy or granulomatous infection was noted.

The patient was discharged on the second postoperative day with instructions for daily wound inspection and dressing changes. Sutures were removed on postoperative day 10. At a six-month follow-up, the incision was completely healed, and there were no signs of recurrence.

Dermoid sinus disease, although less common than other sinus pathologies, may present in various anatomical sites. When located in an atypical region such as the infraclavicular area, it can be confused with: (a)Chronic abscess or infected sebaceous cyst9; (b)Hidradenitis suppurativa10 ; (c) Cutaneous tuberculosis or atypical mycobacterial infection11; (d) Fistula from underlying osteomyelitis of the clavicle12-14 and (e) Foreign body granuloma. The differentiating features are enumerated in Table 2.

Several factors may contribute to the formation or persistence of a dermoid sinus, including congenital entrapment of ectodermal components and friction or irritation in the affected region.1 Imaging (ultrasound and MRI) is essential for delineating the extent of the sinus tract and ruling out deeper involvement.15

A complete surgical excision of the dermoid sinus tract remains the mainstay of treatment to prevent recurrence. Techniques may vary depending on the location and complexity of the lesion.1,2 In some cases, healing by secondary intention or flap-based closures are employed, but for this patient, primary closure was feasible and successful. Postoperative complications can like wound infection, dehiscence, or sinus recurrence have been reported. A close follow-up is vital to ensure proper wound healing and to catch any early signs of recurrence. In this case, the child’s wound healed without complication, and there was no recurrence at six months.

This case illustrates an unusual presentation of a dermoid sinus in the right infraclavicular region in a 7-year-old child. Despite its rarity, clinicians must consider dermoid sinus in the differential diagnosis of persistent subcutaneous sinus tracts—particularly those containing hair—in less typical locations. Appropriate imaging and thorough surgical excision are crucial for successful management and to minimize the risk of recurrence.   

Take Home Message

• Dermoid sinus although rare in children can be seen
• The presentation of Dermoid sinus in a atypical site like infraclavicular area should be excised completely and differentiated from chronic abscesses, infected sebaceous cysts, or other cutaneous infections.
• Appropriate screening and excision can minimize the risk of occurrenc

Figure 1 Legend: Location of the sinus area

Figure 2 Legend: Intraoperative photo showing an elliptical incision around the sinus opening, exposing the tract containing hair shafts and keratinous debris.

Figure 3 Legend: Histopathology slide displaying hair shafts, keratinous debris, and granulation tissue with chronic inflammatory changes typical of a pilonidal sinus.

Table 1: Blood biochemistry profile of patient

Table 2: Table enumerates the differential diagnosis of Dermoid Sinus

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