Diagnosis: Folliculitis keloidalis nuchae.
Folliculitis keloidalis nuchae (also known as acne keloidalis) is a rare primary scarring alopecia characteristically involving the nape of the neck and occipital region and typically afflicting adult African American males younger than 40 years.1,2 Grossly, the lesion begins as follicular papules and pustules that progressively enlarge, forming confluent thickened plaques with or without draining sinuses.1 When seeing the lesion late in the disease process, a malignant neoplasm may be considered. Overall, the pathogenesis remains unknown. Postulated mechanisms include in-curving hairs with or without trauma (from football helmets, etc) and secondary bacterial infection leading to a scarring inflammatory process.1,3 Associations listed in the medical literature include antiepileptic drug or cyclosporine use,1,4 elevated testosterone levels,5 seborrheic dermatitis,5 frequently cut hair (short hair) in African descendents,6 and elevated mast cell numbers in the occipital region.1 Some individuals with folliculitis keloidalis nuchae have reportedly developed secondary cutis vertices gyrata characterized by deep furrows and convolutions of the scalp.1
Pathology Quiz Case 2: Diagnosis. JAMA Otolaryngol Head Neck Surg. 2013;139(4):426. doi:10.1001/jamaoto.2013.140b