Which finding most strongly supports a diagnosis of HS rather than an isolated abscess

A 29-year-old patient presents with a tender nodule in the right axilla. The patient reports four similar episodes during the past year, including two in the groin. Previous lesions drained without a procedure and left dark marks. Examination shows one deep tender axillary nodule and several paired comedones. No tunnels are visible.

Which finding most strongly supports a diagnosis of HS rather than an isolated abscess?