This patient has acne keloidalis nuchae (AKN), which is characterized by firm, skin-colored, pink, or hyperpigmented papules that are often centered on hair follicles. AKN often occurs on the back of the neck and is similar in appearance to pseudofollicular barbae, which occurs on the hair-bearing face and anterior neck. These conditions are most likely due to ingrown hair and are more frequent in persons of color with curly hair owing to the shape of the hair and hair follicle. AKN can cause keloid formation associated with chronic folliculitis at the back of the neck. Therapy aims to minimize inflammation and secondary infection, flatten scars, and alter damage done by hairs. Topical and oral antibiotics, glucocorticoids (topical or intralesional), changes in shaving habits, and laser hair removal can be utilized, often in combination. Changes to shaving habits that are recommended include liberal use of shaving cream, avoidance of stretching the skin when shaving, and use of a single-blade razor rather than a multi-blade razor.

The differential diagnosis includes acne vulgaris and bacterial folliculitis. Inflammatory acne consists of erythematous pustules, nodules, or cysts (deeper and often painful) and are the result of inflammation in and around the hair follicles. This patient has only inflammatory papules and lacks comedones, which would be expected if this was acne. Bacterial folliculitis presents with red papules and pustules centered on hair follicles. The beard, pubic areas, axillae, and thighs are most often affected. Acne and folliculitis do not usually heal with fibrotic papules.

Keloids are areas of exuberant scar formation. A keloid is a tuberous growth of scar tissue that extends beyond the limits of the original injury. Any type of injury to the skin, including internal (acne) or external (trauma or surgery), can trigger keloids. Keloids most frequently occur on the earlobe and upper torso. People of African or Asian descent have a higher risk of keloid formation.